LIBKARY yjJIVERSITY OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA partment of Wa ter Resources BULLETIN No. 98 NORTHEASTERN COUNTIES GROUND WATER INVESTIGATION VOLUME TEXT EDMUND G. BROWN Governor State of California FEBRUARY 1963 ^cu 2 iy63 Ll.. Y WILLIAM E. WARNE Administrafor The Resources Agency of California and Director Department of Water Resources NORTHEAStE.., ,,.^^.,, GROUND WATER INNi^^ffcATION state of California THE RESOURCES AGENCY Of CAllfORNU Department of Water Resources BULLETIN No. 98 NORTHEASTERN COUNTIES GROUND WATER INVESTIGATION VOLUME TEXT FEBRUARY 1963 EDMUND G. BROWN Governor State of California UBRARY PNIVERSITY OF CALIFORNIA DAVIS WILLIAM E. WARNE Administrtrior The Resources Agency of California and Director Department of Water Resources a2ABLE OF COHTEHTS LETTER OF TRANSMITTAL xxi ORGANIZATION, DEPARTMENT OF WATER RESOURCES xxii ORGANIZATION, CALIFORNIA WATER COMMISSION xxiii ACKNOWLEDGMENT xxIt CHAPTER I. INTRODUCTION 1 Origin and Authorization for Investigation 2 Objective and Scope of Investigation k Geologic Data 6 Well Data 7 Water Quality Data 9 Precipitation Data 9 Geography and Economy of the Area of Investigation 9 Population 11 Present Economy and Development I3 Mining 13 Timber I5 Agriculture I5 Recreation I5 Access 16 Soils 16 Climate I8 Drainage Basins and Ground Water Basins I9 111 Page Central Valley Drainage Basin i^ Lahontan Drainage Basin 22 Water Svpply and Demands 22 Water Supply 22 Demands 2$ Organization of Report 25 CHAPTER n. GEOLOGY AND HYDROLOGT 2? Oeologyt A Fundamental Part of Ground Water Studies ... 27 Geologic Formations 27 Geologic Structure 28 The Geologic Map 30 The Relationship Between the Geologic Materials and Ground Water 31 The Ground Water Basins .•• 3^*- Hydrologyi From Precipitation to the Well ..».•..• 35 Well Yield: A Function of Geology and Hydrology 38 Water Quality ......... 39 Measuring the Hazard in Irrigation Water ^0 Total Dissolved Solids ^1 Sodium ^1 Boron ^2 Hazards in Domestic Waters •.•.• k2 At'senic ^2 Flttoxdde k2 Iron ^3 Nitrate k3 IT Page OiAPTBR III. GEOLOGIC HISTQRT AND JtHttlATIONS .... h^ Geologic History of Northeastern California ^5 Geologic Formations of Northeastern California ...... ^0 Basement Complex Rocks ^0 Metamorphic Rocks (pKn) ^0 Granitic Rocks (JKgr) ^0 Volcanic Rocks ^i Sierran Volcanic Rocks (Tst, Tsvb, Tsva, and Tsvp) 3I Cedarville Series (Tnc) ^2 Turner Creek Fonnation (itatc) ^2 Big Valley Mountains Volcanic Series (iVb) ... 52 Miocene Volcanic Rocks (Ttev, Trnvh, Tuva, Tmvp). • 53 Rhyolite (Tvr) 514. Pliocene Volcanic Rocks (Tpvb, Tpva, Tpvp). ... 54 Plio- Pleistocene Volcanic Rocks (TQvb, TQvp), . . 55 Warm Springs Tuff (TQvt) 56 Pleistocene Volcanic Rocks (Qpvb, Qpvp) 57 Cinder Cones ( -^|c- ) 58 Recent Basalt (QrVb) 38 Sedimentary Deposits 59 Fort Sage Sandstone (Tfs) 59 Gold Run Sandstone (Tgs) 59 Auriferous Gravels (Teg) 59 Deep Creek Conglomerate (T0dc) 60 Forty-Nine Camp Formation (Tmfc) 60 Page Pliocene Lake Deposits (Tpl) 6o Alturas Fomation (TQa) . 6l Bleber Formation (TQb) 6l Moraines (Qpm) ••.*. 62 Glacial Oatvash (Qpo) 62 Pleistocene and Lahontan Lake Deposits (Qpl)* . • 63 Near-Shore Deposits (Qps) 63 Terraces (Qt) 6^4^ Alluvial Fans (Qf ) Sk Intermediate Alluvium (Qal) 66 Basin Deposits (Qb) 66 Muck and Peat Deposits (Qmp) 66 Talus (Qta) 66 Landslides (Qls) 66 Recent Lake Deposits (Ql) 67 Sand and Silt Deposits (Qs) 67 Sand Dunes (Qsd) 6j CHAPTER IV. GROUND WATER 69 Goose Lake Valley Ground Water Basin 73 Geologic History 77 Water-Bearing Formations 77 Pliocene to Pleistocene Lava Flews 19 Near-Shore Deposits 79 Recent Valley Sediments 79 Influence of Geologic Structure on Ground Water ... 80 Page Recharge and Movement of Ground Water 83 TfCllow Ranch Siibbasin 85 Davis Creek Siibbasin 85 Franklin Creek Subbasin 87 Present Use of Groiind Water 88 Groxind Water Development Potential •... 88 ■A» Zone 88 "B* Zone , 89 "C Zone •• , , 90 •D" Zone 90 General 91 G3ro\md Water Storage Capacity 92 Quality of Ground Water 92 Water Quality Problems 92 Conclusion ,, 93 Alturas Ground Water Basin 95 Geologic History 96 Water-Bearing Formations 96 Plio-Pleistocene and Pleistocene Lava Flows . • . 98 Alturas Formation ,, 98 Near-Shore Deposits , 99 Recent Valley Sediments 99 Influence of Geologic Structure on Ground Water. ... 99 Recharge and Movement of Ground Water . 102 South Fork Pit River Valley Subbasin 104 Warm Springs Valley Subbasin IO5 Present Use of Grovmd Water •••••• 106 Ground Water Development Potential •• 107 •A" Zone 107 "B" Zone IO7 "C* Zone 108 •D" Zone IO8 Qeneral IO9 Qrotmd Water Storage Capacity ..•••.....•• 109 Quality of Ground Water 109 Water Quality Problems 110 Conclusion «• HO Big Valley and Round Valley Ground Water Basins ...... 113 Geologic History UH- Water-Bearing Formations ••••• ••••• ^3 Pliocene to Pleistocene Lava Flows ••••••• H^ Bleber Formation • 13.5 Recent Valley Sediments ••• •••• 117 Influence of Geologic Structure on Grormd Water • • • HT Recharge and Movement of Ground Water .••....• 120 Big Valley Ground Water Basin • • 122 Round Valley Ground Water Basin 123 Present Use of Ground Water • 123 Ground Water Development Potential .• • 12lt- Big Valley "B* Zone 12^ Big Valley "C" Zone 12^ Big Valley "D* Zone 126 vlll Page Big Valley Ckintiguous Areas 126 Round Valley "B" Zone 126 Round Valley "C" Zone •..., 127 Round Vallej *D" Zone ».••• 127 General •• ...... 127 Ground Water Storage Capacity ..».• 128 Quality of Ground Water 128 Water Quality Problems , 129 Conclusion , 129 Fall River Valley Ground Water Basin 131 Geologic History , 131 Water-Bearing Formations 132 Pliocene to Recent Lava Flovs ••.••....• 132 Lake and Near-Siore Deposits ..•...••.. 131^ Recent Valley Sediments X35 Influence of Geologic Structure on Groxrnd Water ... 137 Recharge and Movement of Ground Water I38 Present Use of Ground Water lI^O Ground Water Development Potential ^.kl ■A" Zone , 2.1^1 •B" Zone ,. iln "C» Zone II4.2 •D" Zone 2X2 General ll{.2 Ground Water Storage Capacity ,. 142 Quality of Ground Water ll».2 tx Page Water Quality Problems Ik3 Concl\islon 114-3 Sierra, Mohawk, and Humbug Valleys Ground Water Basins . . 114.5 Geologic History 114-6 Water-Bearing Formations 114-7 Pleistocene Lava Flows •.•.••.••.•»• ll4-7 Glacial Outwash II4-9 Lake and Near-Shore Deposits II4-9 Becent Valley Sediments ll4-9 Influence of Geologic Strvicture on Ground Water . . . 15O Recharge and Movement of Ground Water 155 Sd.erra Valley Ground Water Basin • 155 Mohawk Valley Ground Water Basin 157 Present Use of Ground Water 157 Groxmd Water Development Potential I58 Sierra Valley "A" Zone 159 Sierra Valley "B" Zone 159 Sierra Valley "C" Zone 159 Sierra Valley »D* Zone 160 General I60 Mohawk Valley "B" Zone I60 Mohawk Valley "C" Zone I6I Mohawk Valley "D" Zone I6I Ground Water Storage Capacity I6I Quality of Ground Water 1^1 Water Quality Problems I62 Concliislon •..•• 1^2 Stirprlse Valley Ground Water Basin • 1^^ Geologic History I65 Water-Beairing Formations I66 Near-Shore Deposits ..• 166 Recent Valley Sediments I68 Influence of Geologic Structure on Ground Water ... 3.69 Recharge and Movement of Ground Water 1Y2 Present Use I76 Ground Water Development Potential • 176 "A* Zone 177 •B" Zone I77 ■C" Zone 178 "D" Zone I78 East Side Valley Lands I78 General • 178 Ground Water Storage Capacity 179 Quality of Ground Water I79 Water Quality Problems I80 Conclusion I81 Madeline Plains Ground Water Basin 183 Geologic History l8'4- Water-Bearing Formations .... ..... 18^ Plio-Pleistocene and Pleistocene Lava Flows ... 185 Pleistocene Lake and Near-Shore Deposits .... 185 Recent Valley Sediments I87 Page Influence of Geologic Structure on Ground Water ... I67 Recharge and Movement of Ground Water I88 Present Use of Ground Water 190- Ground Water Development Potential • 190- "A" Zone 1% »B» Zone 192 "C* Zone 192 »D" Zone 192 General 192 Ground Water Storage Capacity 193 Quality of Ground Water 193 Water Quality Problems 193 Concluslosi 193 Willow Creek Valley and Secret Valley Ground Water Basins . 195 Geologic History I96 Water-Bearing Formations ... ..... 197 Plio-Pleistocene to Recent Lava Flows I97 Pliocene Lake Deposits ............. 199 Recent Valley Sediments ..... 199 Influence of Geologic Structure on Ground Water ... I99 Recharge and Movement of Ground Water 200 Present Use of Ground Water 201 Ground Water Development Potential of Willow Creek Valley 203 •B" Zone 203 ■C" Zone 203 General .••.•••..•.'• • 203 jdi Page Ground Water Development Potential of Secret Valley. . 203 Quality of Ground Water 20i|- Water Quality Problems 2()k Conclusion 20ll- Honey Lake Valley Ground Water Basin .•.••• 20^ Geologic History 206 Wateivfiearing Formations 207 Pliocene Lake Deposits 207 Plio-Pleistocene and Pleistocene Lava Flows • . • 207 Lahontan Lake and Near-Shore Deposits ...... 207 Recent Valley Sediments 209 Influence of Geologic Structure on Groxind Water ... 209 Recharge and Movement of Ground Water •.••..•• 213 Present Use of Ground Water •«•• 215 Ground Water Development Potential •••.•••«.• 2l6 "A* Zone 2l6 »B" Zone 2l6 «C" Zone 2l6 "D" Zone ..• 23^7 General •.....• 217 Grotind Water Storage Capacity 217 Quality of Ground Water 218 Water Quality Problems 2l8 Conclusion ........ 219 CHAPTER V. CONCLUSIOHS 221 Accoinplishments ••.. »...• 221 xiii Page Conclusions 222 TABLES Number ' Page 1 Well Data Available for GroTind Water Basins Investigated 8 2 Water Quality Analyses 10 3 Area and Population of Northeastern Counties: 1950 and i960 Ih k STirface Drainage and Valley Jloor Areas 21 5 Estimated Average Seasonal Natural Runoff From Each Hydrographic Unit Within the Area of Investigation 2k 6 Estimated Ultimate and Limited Ultimate Mean Seasonal Water Requirements in Each ^drographic Unit Within the Area of Investigation 26 7 Distribution and Water-Bearing Importance of Geologic Units in Northeastern California 29 8 Ground Water Basins 36 9 Geologic Formations in Goose Lake Valley 78 10 Geologic Formations in Alturas Bsisin 97 11 Geologic Formations in Big Valley and Round Valley Area II6 12 Geologic Formations in Fall River Valley 133 13 Geologic Formations in Sierra, Mohawk, and Humbug Valleys ikS Ik Geologic Formations in Surprise Valley 167 15 Geologic Formations in Metdeline Plains I86 xlv Nrimber Page 16 Geologic Formations in Willow Creek Valley and Secret Valley I98 17 Geologic Formations in Honey Lake Valley .... 208 FIGURES Ntunber Page 1 Population Within Census County Divisions, I960 . 12 2 Valley Floor Areas Investigated • 20 3 Hydrographic Unit Designations i^pearing in Bulletin No. $6, Northeastern Counties Investigation 23 U Occurrences of Ground Water 33 5 Iftxconfined and Confined Groxind Water •*.... 33 6 Looking Back in Geologic Time k6 7 Diagraaonatic Section of TJnpical Basalt Flow • • • ^6 8 Longitudinal Section Along Typical Alluvial Fan . 65 19 3 9 Generalized Geologic Section A-A -A^-A"', Goose Lake Valley Ground Water Basin ........ 81 10 Generalized Geologic Section B-B , Goose Lake Valley Ground Water Basin , 82 11 Generalized Geologic Section A-A"'"-A^, Alturas Ground Water Basin 100 12 Generalized Geologic Sections B-B"^ and C-C^, Alturas Ground Water Basin •• • 101 13 Generalized Geologic Section A-A , Big Valley and Round Valley Ground Water Basins • • ll3 lU Generalized Geologic Section B-B^, Big Valley Ground Water Basin • 119 15 Generalized Geologic Section A-A^* Fall River Valley Ground Water Basin I35 16 Generalized Geologic Section B-B"^, Fall River Valley Ground Water Basin ••••• 138 XV Nuaiber 17 Oeneraliaed Geologic Section A-A-^-A^, Sierra Valley Ground Water Basin I5I 18 Generalized Geologic Section fr-B-^-B^, Sierra Valley Groimd Water Basin I52 19 Generalized Geologic Section G-C > Mohank Valley Ground Water Basin 1^ 20 Generalized Geologic Section A-A t Surprise Valley Ground Water Basin I70 21 Generalized Geologic Section B-B > Suzprise Valley Ground Water Basin • 171 22 Generalized Geologic Section A-A^-A^-A^, Madeline Plains Ground Water Basin I89 23 Generalized Geologic Section B-B^, Madeline Plains Ground Water Basin I90 2U Generalized Geologic Section A-A-^, Willow Cre^ Valley Ground Water Basin • 202 25 Generalized Geologic Section B-B , Secret Valley Ground Water Basin 202 26 Generalized Geologic Section A-A^, Honey Lake Valley Ground Water Basin ••• 211 27 Generalized Geologic Section B-B*'-, Honey Lake Valley Ground Water Basin pit 28 Generalized Geologic Section C-C^-C^, Honey Lake Valley Ground Water Basin 212 ILLUSTRATICNS ( ToUoidiig Page 46) Warner Mountains, iiest of Surprise Valley Hays Canyon Range, east of Surprise Valley Goose Lake, Warner Mountains in the background Fall River Mills, Fall River in foreground Road cut west of Fall River Mills xwl Devils Garden, southwest of Goose Lake Wendel Fan, Honey Lake Valley Owl Creek, west of Surprise Valley Hot Springs near Cedar Plunge, Surprise Valley Wendel Hot Springs, Honey Lake Valley Sprinkler irrigation from ground water, near Pittville Slysian Valley, west of Honey Lake Artesian stock well. Sierra Valley Hot spring, east of Cedarville, Surprise Valley Stock well in Sierra Valley Irrigation well in Honey Lake Valley PUTES (Plates contained in Volume II) Number 1 Area of Investigation 2 Geographical Distribution of Precipitation in Northeastern California 3 Areal Geology, Goose Lake Valley Ground Water Basin U Generalized Lines of Equal Elevation of Water in Weils in Near-Surface Aquifers, Goose Lake Valley Ground Water Basin, Spring I960 5 Generalized Lines of Equal Elevation of Water in Wells in Confined Aquifers, Goose Lake Valley Ground Water Basin, Spring I960 6 Potential for Development of Ground Water, Goose Lake Valley Ground Water Basin 7 Areal Geology, Alturas Ground Water Basin 8 Generalized lines of Equal Elevation of Water in Wells in Aquifers, Alturas Ground Water Basin. Spring I960 xvxx Ntmiber 9 Potential for Beyelopment of Grotind Water, Alturas Ground Water Basin 10 Areal Geology, Big Valley and Round Valley Ground Water Basins 11 Generalized Lines of Equal Elevation of Water in Wells in Near-Surface Aquifers, Big Valley and Round Valley Ground Water Basins, Spring I960. 12 Generalised Lines of Equal Elevation of Water in Wells in Confined Aquifers, Big Valley and Round Valley Ground Water Basins, Spring I960 13 Potential for Development of Ground Water, Big Valley and Round Valley Ground Water Basins lU Areal Geology, Pall River Valley Gz'ound Water Basin 15 Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Fall River Valley Ground Water Basin, Spidiig I960 16 Potential for Development of Groxind Water, Fall River Valley Groimd Water Basin 17 Areal Geology, Sierra, Mohawk, and Humbug Valleys Grouixi Water Basins 18 Generalized Lines of Equal Elevation of Water in Wells in Near-Surface Aquifers, Sierra, Mohairic, and Humbug Valleys Ground Water Basins, Spring I960 19 Generalized lines of Equal Elevation of Water in Wells in Confined Aquifers, Sierra, Mohatric, and Hundsug Valleys Ground Water Basins, Spring I960 20 Potential for Development of Ground Water, Sierra, Mohawk, and Humbtig Valleys Grotind Water Basins 21 Areal Geology, Surprise Valley Ground Water Basin 22 Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Surprise Valley Ground Water Basin, Spring i960 23 Potential for Development of Ground Water, Surprise Valley Ground Water Basin 2k Areal Geology, Madeline Plains Ground Water Basin xviii Number 25 Generalized Lines of Bqual Elevation of Water In Wells In AqiiLfers, Madeline Plains Qrovind Water Basin, Spring i960 26 Potential for Development of Groimd Water, Madeline Plains Ground Water Basin 27 Areal Geology, Willow Creek Valley and Secret Valley Grovind Water Basins 28 Generalized Lines of Eqiial ELevation of Water in Wells in Aquifers, Willow Creek Valley and Secret Valley Ground Water Basins, Spring I960 29 Potential for Development of Ground Water, Willow Creek Valley and Secret Valley Ground Water Basins 30 Areal Geology, Honey Lake Valley Ground Water Basin 31 Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Honey Lake Valley Ground Water Basin, Spring i960 32 Potential for Developraent of Ground Water, Honey Lake Valley Ground Water Basin APPENDIXES Appendix Page A DEFINITIGNS A-1 B BIBLIOGRAPHY B-1 XLX EDMUND 6. BROWN IlllAM E. WARNC Diractor of Wcrtar RMOurcM kBBOn GOLDBERG M Daputy Director OINAIO C. MtlCE Mity Dlractor Policy '^'lEELY GAKDNER . D*pu«y Dlractor AdmlnUtratlon .LFRED R. GOLZE Chltf Engliwor WILLIAM E. WARNE ADMINISTRATOR RESOURCES AGENCY ADDRESS REPLY TO P. O. Box 388 SacranMnto 2, Calif. THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES 1120 N STREET, SACRAMENTO November 29, I962 Honorable Edmund G. Brown, Governor, and Members of the Legislature of the State of California Gentlemen : I have the honor to transmit herewith Bulletin No. 98^ "Northeastern Counties Ground Water Investigation." This bulletin sumnarizes the investigation approved by the Legislatiore and for which funds were first appropriated by the Budget Act of 1957 (Item 263.C). Bulletin No. 98 includes plates showing the most detailed areal geology of the northeastern counties published to date. The bulletin also presents the first published information concerning the subsvirfewje geology of the ground water basins within this area. Based upon geologic and all other data collected during this investi- gation, preliminary evaluations of the potential for ground water development within these ground water basins of the northeastern counties are presented. Sincerely yours. ^;.^c_r^>*^ Director STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES EDMUND G. BROWN, Governor WILLIAM E. WARNE, Administrator, The Resources Agency of California and Director, Department of Water Resoxirces ALFRED R. GOLZE, Chief Engineer JOHN R. TEERINK, Assistant Chief Engineer NORTHERN BRANCH John M. Haley Branch Chief John W. Keysor. . .Chief, Planning Section The investigation leading to this report was conducted vmder the direction of Stuart T. Pyle Senior Engineer by Robert S. Ford Associate Engineering Geologist Joseph N. Soderstrand Associate Engineer Russell E. Franson . . . Water Resources Engineering Associate Freeman H. Beach Assistant Civil Engineer Stanley A. Feingold Assistant Civil Engineer W. Roger Hail Assistant Engineering Geologist Thomas I. Iwamura Assistant Engineering Geologist Arvey A. Swanson Assistant Engineering Geologist xxii CALIFX)RNIA WATER CCMMISSION RALPH M. BRODY, Chairman, Fresno WILLIAM H. JENNINGS, Vice Chairman, La Mesa JOHN W. BRYANT, Riverside JOHN P. BUNKER, Gustine IRA J. CHRISMAN, Visalia GEORGE FLEHARTY, Fresno JOHN J. KING, Petal \ma NORRIS POULSON, Los Angeles MARION R. WALKER, Ventura 0- WILLIAM M. CARAH Executive Secretary GEORGE B. GLEASON Principal Engineer xxiii ACKNWLEDGMENT During this Investigation landowners, well dzillers, and IndividTialSy too numerous to specifically acknowledge} provided valtiable assistance to department personnel in the collection of basic data. Those idu> observed and compiled climatic and lake stage data devoted many hours to the collection and preparation of information. Their cooperation is gratef\illy acknowledged* Specific acknowledgment is made to the following agencies and organizations t Bureau of Land Management, United States Department of the Interior Corps of Engineers, IMited States Army Forest Service, United States Department of Agriculture Soil Conservation Service, I&iited States Department of Agriculture Agricultural Extension Service, Ifaiverslty of California California Division of Forestry California Division of Highways California Division of Mines and Geology Sierra-Pacific Power Company Western Pacific Railroad xxLv CHAPTER I. INTRODUCTION Developnient of the water resources of California reqiilres that investigations be initiated many years prior to the need for water to insure proi)er economic growth. Recommendations concerning the development of California's water resources should be based upon consideration of all means of supplying foreseeable demands. The utilization of ground water in conjtmction with plans to develop surface supplies is one method of providing future supplies when needed. Previovis investigations have determined that the northern peurt of the State as a whole prodiices more water than it reqiiires for full devel- opment. Unfortunately, this excess water is not equally available to all peurts of Northern California. Areas in the .northeastern part of the State axe so located that economl cal develojineiit of STirface supplies cannot satisfy predicted needs for water. Knowledge concerning the ground water resources within these areas has been lacking in the past but is needed so that continued development of this valviable segment of the water supply cam be realized. The primary aim of the Northeastern Counties Gro\ind Water Investigation was to make the studies necessary to establish a fsLctual basis for evaltiating the ground water potential of several ground water basins located in Northeastern California. Preliminary evaluations of this potential ba^ed upon the data collected axe presented euid discussed In this bulletin. Additional investigations and considerable study will be required to evaluate fully the potential for grotmd water development within the axeas investigated. -1- Origin and Authorization for Investigation The need for a study of the ground water potential of several ground water basins in Northeastern California was shown by past investi- gations by the Department of Water Resources. A comprehensive survey of the water supplies, water needs, and possible water developments within this area was made as part of the statewide water resovirces investigation conducted iinder the direction of the California State Water Resources Board during the period from 19'4-7 to 1957- Encompassing the entire State, the study was conducted euad reported upon in three phases. The first phase consisted of an inventory of the basic water resources of the State. Bulletin No. 1, "Water Resources of California," published in 1951, presented a compilation of data on precipitation, natural stream runoff, flood flows, and water quality. Bae second phase involved estimates of present and ultimate water requirements on a statewide basis. Bulletin No. 2, "Water Utilization and Requirements of California," Jvine 1955, Includes determinations of present use of water for consumptive purposes and forecasts of ultimate water require- ments based upon the capability of the land to support further development. Bae concluding phase of the statewide investigation is contained in Bulletin No. 3, "The California Water Plan," dated May 1957* ^e California Water Plan has been adopted by the Legislature as a comprehensive master plan to guide and coordinate the activities of all agencies for developing California's water resources for all beneficial purposes. In general, it shows that the water supply of the State is sufficient euad can be properly developed to meet the forecasted futiore demands for water. The statewide investigation pointed out many problems and recommended continuing studies for their further analysis. -2- An area containing many problems associated with its present and potential water develonnent comprises the 15 northeastern counties of Butte, Colusa, Glenn, LaJce, Lassen, Modoc, Plumas, Shasta, Sierra, Siskiyou, Sutter, Tehama, Trinity, Yolo, and Yuba. In 195^ the Legislature provided for an investigation emd determination of ultimate water needs of these counties, predicated upon the full development of all other natural resources. This study included a much more detailed analysis of both water supply £uad water requirements than was possible in the statewide study. The resxilts^ published in Bulletin No. 58, "Northeastern Counties Investigation," dated June 1960^/, showed that ultimate water requirements for some portions of the northeastern counties would exceed the potential surfewje water supplies that could be develciped eccMiOBiically from local sources. The areas with limited water supplies are mainly within the mountain valleys east of the Cascade Reuige and Sierra Nevada in Modoc, Lassen, Plumas, and Sierra Counties. A reconnaissance study of the geology and ground water conditions within these valleys, made as peurb of the Northeastern Counties Investigation, showed that more detailed investigation of the potential for ground water development was warrajited. The Department of Water Resources proposed in I956 that a thorough investigation be made of ten ground water basins in the northeastern counties as p6irt of the California Water Development Program. The valleys proposed to be included were Goose Lake, South Fork of Pit River, Big Valley, and Fall River Valley, all within the Pit River Drainage Area; Siirprise Valley, Madeline Plains, Willow Creek Valley, and Honey Lake Valley, all closed basins; and Sierra Valley and Mohawk Valley within the Feather River Drainage Area. Most of these were shown in Bulletin No. 58 to have ultimate water requirements in excess of their available surface water supply. 1/ The .preliminary edition was published in December 1957. OJie Legislatttre approved the proposal for the Northeastern Counties Ground Water Investigation, and in the Budget Act of 1957 (Item 263. c) appropriated $75^90 to begin work. During the five fiscal years from 1957-58 through 1961-62, a total of about $560,000 vas made available to carry this vork to completion. Objective emd Scope of Investigation The original objective of the Northeastern Counties Ground Water Investigation vas to collect all data relevant to the occurrence and move- ment of ground water in the ten basins, to analyze the hydrology of the ground water basins aixd to estimate the probable safe yield and potential for development of each basin. The data collection program was initiated to provide Information regarding the extent and character of the ground water basins, the number of wells, amounts of water produced by the wells, and other factoirs to aid in the evaluations. Prior to this investigation there had been no comprehensive studies of ground water in any of these areas. Q)ere were no data available on the locations of wells or historical water levels. Existing geological information was generall2sed for broad areas or developed in detail for limited aresus for such purposes as mining or damslte studies. Field Investigations for this investigation disclosed that the limited development of the ground water in seme basins would not provide sxifficient data to determine items such as specific yield, storage capacity, and changes in the volume of ground water storage, needed for quantitative evaluation of the potential for ground water developoent. As a result, studies of water supply and water use to estijnate safe ground water yield could not be cooipleted. Quantitative estimates of the missing items needed for the hydrologic analysis of several ground water basins were made, but the results were Inconclvisive. -k- Therefore, much of the emphasis of tMs Investlgsttlon was placed on the collection of data regarding veils and vater levels and on detailed sttidy of the geology of the ground vater basins. The Investl^tlon of geologic conditions vas Intensely pursued as the foundation to understanding the characteristics of the ground vater basins. The Information collected vas extremely useful, and from It preliminary general evaluations have been made of the potential for ground vater development. Considerable emphasis vas placed upon correlation and analysis of data pertaining to the occurrence and movement of ground vater. Such data vere obtained by conducting geologic studies to ascertain the characteristics of the vater-beeurlng formations, by collecting Information relating to the yield of veils, by measuring vater levels In veils, and by taking vater saniples so the quality of vater could be analyzed. Many precipitation stations vere established by the department and maintained by residents of the area to provide rainfall measurements In axeoA for vhlch no data previously existed. Details of the geologic Investigations and vater quality studies are contained In unpublished office reports prepared during the Investigation. Basic data obtained by the continuing data collection activities of the department vUl appear In futixre publications. The evaluations of the ground vater potential In each beuiln axe shown on plates Mhlch vlll be presented and discussed In this bulletin. The Investigation shoved that ground vater may provide an econoiii- Ical source of vater supply In conjunction vlth surface supplies. !nie data collected and compiled during this Investigation should also provide the basis for future coniprehenslve qxiantltatlve evaluations of the potential for ground vater development. -5- GeoLoglG Data A geologic mapping program vas Initiated for each ground vater basin Investigated. !Qie 8u%a dapped for each basin vas scheduled to Include as nruch of the probable recharge areas as possible. Beca\ise of the close proximity of adjoining recharge areas, the mapping program vhen completed provided full coverage of the entity region of Northeastern California In vfalch the several basins are located. Tibe geologic mapping program began vlth compilation of all available published and unpublished geologic maps and reports of the region. Original geologic mapping vas then carried out as needed for this Investigation, partlciilarly In the main valley areas. Subsurface geologic conditions were evaluated Initially from data obtained from logs of water wells. Additional subsurface data were collected from test holes drilled during the Investigation. Seven test holes were drilled In Surprise Valley, and samples of water-bearing and nonwater-bearlng materials were studied. OSiese test holes ranged In depth from 13 to 301 feet. Twenty- two test holes were drilled In Big Valley. Of these latter holes, 20 were auger holes ranging In depth from 20 to 2k feet. !Ilhe other two were deep test holes emd were drilled to depths of 1,231 feet and l,81v3 feet, respectively. Samples were obtained from both deep test holes, and an electric log and a micro-log were made of the deeper hole. Additional subsurface data wez*e collected firom gravimetric studies made In Big Valley, Sierra Valley, Surprise Valley, and Honey Lake Valley. Through evaluation of data collected In these surveys, the probable depth to bedrock beneath the floor of the valley was determined. In eiddltlon, the locations of many of the faults which pass beneath the valley floor were ascertained. A seismic survey was made for a portion of Sierra Valley In cooperation with the United States Geological Survey. The seismic survey -6- provided information to evaluate the depth to bedrock and the probable loca- tion' and extent of several bviried lava flows. Well Data In each valley as many wells as possible were located aad e xamin ed. Information was soiight from owners and well drillers regarding the subsiirface formations into which the wells were drilled, the elevations of water in the wells, and the amount of water produced by the wells. Elevation of each of the wells was determined by field svtrveys. Use was also made of vertical control surveys conducted by other agencies. A program to make periodic measurements of depth to ground water was established for selected wells throughout the valleys. As a result of the Northeastern Countxes Ground Water Investigation, well measvirements will continue to be made monthly for a few wells within the valleys as part of the department's ground water measurement program. In addition, over 500 wells will be measured once every five years and used to prepare maps showing^ lines of equal elevation of water in wells. Table 1 lists well data available for the ground water basins investigated and indicates the relative degree of developnent in the several basins. Most of the wells have been developed for domestic or stock purposes, and comparatively few are used for irrigation, industrial, or municipal purposes. Table 1, in addition to listing the present use of wells, also indicates the availability of additional information concerning these wells. In the course of the current investigation, 14-88 well logs were obtained from various sources. The information contained therein was useful in evaluating the geology of the area. In interviews with owners and well drillers , information obtained concerning the yield of wells gave some indication as to the quantity of -7- H u a a o a -p u d Q) '9 =1 f-l tft ■p (U "'^ rA ^ V o 4) ca CO 0) t^ M 1-4 1"^ .3^ MD O -d- ro CVJ H CVJ H C\J OJ -+ ^ OJ CO Hoi cvj-^ t;:;- VD Cr\C3\_:f CO rH OJ J- CM -d- O rn O LTN Q CO ir\ONH CO mc\i r-{ en t~ r^ cntr-cr, CO iTNOo CM on LfN LTN^ CM VO CO H VO PuMTN C\l H CU H H CM r- CM L/N ir\MD VD VO VO I H I CKO CM i^ CM COH CTnO CTvl CM ^1 VO oo I Hi CO CO On roOJI J- CT\ C7V H i^ VO u^l 00 VO <^ Cr H Lr\ o\| VO CM O J- J- H H -* I o i) a a H U m ^ td w d ^ 0) J •rl -H > H ^^ H O H >5 u Ti rA > a B a -A o CO s rs w _ft_ water that could be developed from certain geologic formations. The data collected concerning the elevation of water levels in wells were utilized to prepare maps showing lines of equal elevation of water in wells. All of the information collected pertaining to wells is contained in the files of the Department of Water Resources. Water Quality Data To determine the suitability of the ground waters for irrigation and domestic uses, a water quality investigation was undertaken. Following a review of available well data, a group of representative water samples were subjected to a complete mineral ajaalysis. Sajoitary suxalysea were not made because conditions of bacterial contamination, if they existed, would be controlled by Public Health Agencies. Table 2 lists the number of surface and ground water samples analyzed during this investigation for each of the grotind water basins studied. All of the water quality Informa- tion collected during this investigation concerning ground water is contained In the files of the Department of Water Resources. Precipitation Data With the cooperation of tbe local residents in the area of investigation, more than a hundred precipitation stations were established. The precipitation data collected during the investigation were correlated with records from precipitation stations idiich had long periods of record. All available precipitation data were then utilized to prepare a map of the area showing lines of equal mean seasonal precipitation. Geography and Economy of the Area of Investigation The ground water basisis Included in this investigation are located principally In the four northeastern counties of California, adjacent -9- TABLE 2 WATER QUALITY ANALYSES Grovind water liaslns Numiber of water quality analyses Surface : Groimd water : water 13 38 21 Ih 10 70 5 a. 16 GS 37 83 21 36 12(t) 7(b) 1? 1?? Central Valley Drainage Basin Goose Lake Valley (*) Alturas Big Valley and Round Valley Fall River Valley Sierra, Mohawk, and Humbug Valleys Lahontan Drainage Basin Surprise Valley (•) Madeline Plains Willow Creek Valley and Secret Valley Honey Lake Valley (*) Total 150 610 (a) California portion only. (b) All samples indicated were taken in Willow Creek Valley. -10- to the State of Nevada. These counties, from north to south, are Modoc, which lies adjacent to the State of Oregon, Lassen, Plumas, and Sierra. One groxuid water basin investigated and its drainage area extends into Siskiyou and Shasta Counties, which are located to the west of Modoc and Lassen Coxuities. Plate 1, Area of Investigation, shows the valley floor area and the tributary drainage area for each of the ground water beisins investigated .=/ Population The Counties of Modoc, Lassen, Flumas, and Sierra showed decreases in population from 195O to i960. Population losses ranged from a 6.8 percent reduction in Sierra County to a 26. k percent reduction in Lessen County. Mariposa with a 1.6 percent decrease and San Francisco with a. k.^ percent decrease were the only other counties in California to show a population loss in the last decade . In Figure 1, the census county divisions of each of the counties involved in this investigation are shown. The total population in each census county division is shown in bold print on the figure. Population of the communities located within a census county division is indicated in parentheses and is included in the total shown for each cens\is county division. Population data shown in Figure 1 were obtained from "United States Census of Population, I96D, California, Number of Inhabitants, U. S. Department of Coramerce, Bureau of the Census, PC(l), 6a, California." Alturas, with a 196O population of 2,8l9, Is the only city reported upon in Modoc County. Of the ccomunltles for which population figures are given in Lassen Co\mty, only the City of Susanville, with a population of 5,59T, is included within the area of investigation. In 1/ Plates are under separate cover. -11- R E G N LEGEND — -—^^ STATE BOUNDARY — — COUNTY BOUNDARY CENSUS COUNTY DIVISION BOUNDARY (1209) POPULATION WITHIN TOWN IKOK POPULATION WITHIN CENSUS '*'*'' COUNTY OIVISION, VALLEY FLOOR AREAS INVESTIGATED Figure I. POPULATION WITHIN CENSUS COUNTY DIVISIONS, I960 12 Flumas County, four ccoimunities are shown but only the City of Portola, with a population of 1,8714-, is within the study area. Loyalton, with a population of 936, is the oixLy city in Sierra County that is within the study area. A few additional towns and villages with smaller populations are included within the rural population of the area of investigation. Pliiraas County has a population density of 14-.5 persons per square mile; Lassen, 3.O; Sierra, 2.3; and Modoc, 2.0. Only three other counties in California have population densities lower than Modoc County. They are Alpine with O.5, Mono with O.7, and Inyo with 1.2 persons per square mile. The land area and population for 195O and i960 for the counties of Modoc, Leissen, Flumas, and Sierra eire presented in Table 3> Present Economy and Developnent The present economy of the four counties is based upon the devel- opnent and use of their existing natural resources. Mining for gold was probably the first Important development within the area, but this resource is only of in^rtance in quite limited areas today. Timber was initially vised in connection with mining and later became a major segment of the economy. The early settlers found good cattle feed available on the meadow and pasture lands that are in the areas. Agricxiltural pursuits were first centered upon providing food for those engaged in mining and related activities. Recreation has assumed a more lii^rtant aspect of the area's economy, as population pressures in the remainder of the State have created demands for additional recreational aresus. Mining . Mining activity within this area todtay is more concerned with the pzx}duction of non-metallic minerals than the meteCLs, eLLthongh some gold continues to be mined in Sierra County. Soane prospecting for tiranium has been done, but no production has as yet resulted. Commercial -13- TABLE 3 AREA. AND POPULATION OF NORTHEASTERN COUNTIES: 1950 AND I96O County Land area in square miles 1950 Population i960 Percent decrease Lassen ^>^^1 l8,li-T^ 13,597 26.k Modoc ll-,092 9,678 8,308 114-.2 Plumas 2,570 13,519 11,620 li+.O Sierra 958 2,1+10 2,2kl 6.8 vrfcc; -Ik- production of silver, copper, merciiry, or other metals baa not been too successful. Sand, gravel, and crushed rock make up a substantial poirtlon of the total production of nilnerals vlthln the entire area. Throughout portions of the Mortheaistem Counties, various rocks and minerals ajre found vhlch are of Interest to rock collectors and lapidaries, but they have little cQnmerclal value. A type of variegated obsidian found In Modoc County Is of particular Interest to stich collectors. Timber . There are extensive areas of publicly ovmed and privately owned forest lands. Quite recently timber production has been significantly cut back from the relatively high rates of production during World War II and post-var years. Much of the population loss Is attributable to this cut back. Timber Is the most Important non-agricultural Industry and many mills cure found In all of the counties. It Is predicted that the futvire timber harvest vlU be considerably reduced from the peaks of World War II levels but will continue at a long-teim sustained yield basis. Agriculture . From the beginning of the settlement of this area, the beef Industry has been an Importemt segment of the economy because relatively large tracts of land have been available for the grazing of livestock. Natural pastures and range lands are used for cattle grazing. Timbered eireas also are grazed to the extent feasible. Much of the Irrl^ted agrlcultiiore within the valley axeas Is devoted to crops which support livestock. Irrigated pasture, hay, and alfalfa axe the principal crops. Only a very small percentage of the Irrigated axe& Is used for truck or sx>eclalty crops. Recreation . Tourists, campers, hunters, and flshex^nan find that the arid deserts, rugged mountains and forest lemds of the northesustem -15- counties comtsdn seme of the last remaining primitive areas in California. Big game hxinting is an important sport. Rocky Mountain and California mule deer thrive on the seemingly beuren lava plateaus; they browse the brush lands, and range over the moimtain slopes until advancing winter snows slowly herd them back to lower altitudes. Modoc County is one of the few remaining areas in irtilch antelope hunting is legal. Concentrated hiinting of waterfowl occurs in the Croose Lake area, although hunters find waterfowl in other valleys throughout the region. A few idieasaats and quail also are found. Giood fishing is found in many areas, but lack of access prevents extensive fishing in some of the better trout streams in the region. Of the several lakes within the area. Eagle Lake probably possesses the greatest recreational potential and currently is being developed for more intensive use. Camp and picnic areas have been developed thro\ighout the region. Undoubtedly, recreational activities will become a larger part of the general economy. Access . Most of the towns and cGnnminitles in the northeastern counties are accessible by eidequate all-weather federal or state highways. U. S. Highways ho Alternate, 299 and 395 and State Sign Routes 36, k9, 89 and 139 serve the area. Susanville, Alturas, and PortciLa, the three largest communities in the region, are served by the Southern Pacific Company or the Western Pacific Railroad. Big Valley is also served by the Great Northern Railway, and the Western Pacific Railroad. Most of the population centers have airports, or at least landJTtg strips, nearby. Soils High volcanic plateaus and rugged terrain are found in portions of the eurea, while Madeline Plains and other valley areas are relatively flat. In general, the soils found within the axea, investigated may be -16- divided Into two broeul groups; residual soils, vhlch have developed In place, and transx>orted soils. Residual soils occur mainly on hilly and mountainous lands. Soil differences largely are dependent upon variation of peurent material and climatic feu:tors. Soil depth varies from very shallow on scab lands or lands having considerable rock present on the surface and throughout the soil profile, to good depth on lands having little or no irock present. Drainage is usually good. Suitability of much of these soils for irriga- tion development is limited because of the cooiplex topographic conditions; however, certain of these soils are suited for many climatically adapted crops. Transported soils vary in their physical and chemical character- istics according to the nature of the deposition, parent material, and the degree of development that has taken place since their deposition. This group of soils can be broe^y classified as dd valley fillings, basin and lacustrine soils, and Recent alluvium. Soils derived from old valley fillings and remnants of former alluvial fans are extensive in many mountain valleys throughout the north- eastern counties, dese soils have undergone marked changes in profile characteristics since their deposition. Leaching and other soil forming processes have brought about soils varying frcm those underleiin vith dense claypans or cemented hardpans to those with moderately compact subsoils. Agriculturally, these soils are generally siiitable only for crops vith fairly shallow roots. Berlin and lacustrine soils have developed from fine sediments deposited in overflow basins or in fresh water lakes. These soils are normally fine-textured and, doe to limited or restricted drainage, an accumulation of salts is often present. Much of the saline soil could -17- be reclaimed by improvement of local drainage. Certain of the alkali lacustrine soils, beca\ise of the greater difficulty in reclamation, vere not considered as potenticiLly irrigable, particularly in Surprise Valley and Honey Lake Valley. Otherwise, the basin and lacustrine soils are suitable for many climatically adapted medium and shallow rooted crops. Recent alluvial soils occupy flood plains adjacent to stream channels. In general, these soils are moderately deep, friable, euid mediiun-textured and have undergone little or no change in their profile characteristics since deposition. These soils are only found to a limited extent in the ground water basin areas of the northeastern cottnties. dimate In the area voider investigation, the climatic conditions are infltienced to a great extent by the landward movement of water-bearing air masses that originate in the central and northern Pacific Ocean. Abrupt changes in topography, however, cause wide variations In the climate. This is evidenced by the variation of the mean seasonal precipitation from more than 70 inches in a portion of Sierra County to less than 10 Inches in eastern Modoc and Lassen Counties. Plate 2, Geographical Distribution of Precipitation in Northeastern California, indicates the variation in mean seasonal precipitation over the area of investigation. Much of the pre- cipitation falls in the form of snow on the higher mountain ranges, althotigh rain above 8,000 feet sometimes occurs. Heavy snowfall is the iisual winter feature of the Sierra Nevada at elevations above 5,000 feet. Snow falls in moderate amovmts on the mountains and the plateaus in Lassen and Modoc Counties. The northerly and westward movement of the prevailing Pacific high-pressure ridge during the summer results in a practically rainless period during these months, except for local showers and thunderstorms which occur in the mountainous aireas. -18- Temperatxire, vlnd movement, and himildlty axe similarly Influenced by the moYement of the Pacific Coast air masses and the topography of Northern Califonala. Warm, dry STinners characterize the northeastern counties. Maximum daily summer temperatoires in the northern plateaxis often exceed 100 degrees. In the winter, temperatures are lovr in the mountains and plateaus, jreaching at times -30°F. The mountain valley and plateau areas are ustially frost-free from June until the latter part of September, but in many locations frosts may occvir in any nonth of the year. Drainage Basins and Ground Water Basins The valley floor areas in which ground water was Investigated are located either within the Central Valley or Lahontan Drainage Basins, and are shown as shaded axeas on Figure 2. The Central Valley and the Lahontan Drainage Basins are two of the nine major hydrographic divisions of the State of California. The surface drainage areas tribvctary to each ground water basin were determined primarily from the topographic maps available for the areas. The valley floor area usually cannot be as precisely deter- mined as the surface drainage areas \Aich extend to the crests of the surrounding terrain. The limits of ground water basins are determinable by careful consideration of the geologic and topographic conditions of each ground water basin and occurrence of ground water within the various foima- tions as defined on page 34 . The boundaries of the ground water basins were determined for each basin to the extent that data were available and will be presented and discussed in Chapter IV, Ground Water. Table k shows the acreage of the drainage and valley floor areas for each basin. Central Valley Drainage Basin . The areas of investigation within the Central Valley Drainage Basin are located within the Pit River and the Upper Feather River watersheds. The Pit River originates in Modoc County -19- R E 6 N NORTH COASTAL {DRAINAGE BASIN SI SKI Y LEGEND MAJOR DRAINAGE BASIN BOUNDARY VALLEY FLOOR AREAS INVESTIGATED f^ Figure 2. VALLEY FLOOR AREAS INVESTIGATED 20 TABLE h SURFACE DRAIMGE AND VALLEY FLOOR AREAS (in 8K:res) Gro^md water 'basin Drainage area (a) Valley floor area Central Valley Drainage Basin Goose Leike Valley (3») Alturas Big Valley and Round Valley Fall River Valley Sierra, Mohawk and Hunibug Valleys Lahontan Drainage Basin Surprise Valley (b) Madeline Plains Willow Creek Valley Secret Valley Honey Lake Valley (b) '.h 260,000 foc, 121,300 835,000 i-bo'y 76,500 588,000 under natural conditions and do not include runoff from upstream tributary drainage areas. Demands . Futvire demands for water within each hydrographic unit also were evaluated from Bulletin No. ^8, and pertinent abstracts from Table 33 ond. Table 53 a^re shown in Table 6. Under the column headed "Probable Ultimate " are listed the quantities of water needed to satisfy projected ultimate demands within each of the hydrographic units. Bulletin No. 38 concluded that ultimate water requirements in some areas would be limited because of the lack of available water supply. Ifoder the column headed "Limited Probable Ultimate" appear the quantities that could probably be developed and utilized. The develpiment of a water supply to meet limited probable ultimate demands requires increased use of the ground water potential for such an area. Organization of Report Chapter II, Geology and Hydrology, presents the elements of geology and hydrology that form the basis for ground water evaluations. Chapter m. Geologic History and Formations, briefly outlines the geologic history of Northeastern California. A discussion of the geologic and water-bearing characteristics of each of the fozmatlons found in the area is also set forth. Chapter IV, Ground Water, sxmmiarizes for each basin the preliminary evaluations of ground water based upon the available data for each basin. Chapter V, Concluding Remarks, outlines the a-ccoogpllsbments of this investi- gation and presents conclusions and recoomendatlons . An annotated bibliography of reference material used in the course of the investigation immediately follows the test. FLates, because of their size, are included under a separate cover. Fhotograpbs, figures, and tables are found throughout the text. -25- TABLE 6 ESTIMA.TED ULTIMATE AND LIMITED ULTIMATE MEAN^/ SEASONAL WATER REQUIREMENTS IN EACH HYDROGRAPHIC UNIT WITHIN THE AREA OF INVESTIGATION (in acre-feet) Hydrographic unit Water requirements : : Limited Reference Probable : probable number : Name ultimate : ultimate Central ' i^alley Drainage Basin 12 Goose Lake 120,300 120,300 13 Jess Valley 26,000 26,000 Ik *Alturas 30li-,900 ?1 1 ,14-00 15 *Big Valley 219,800 179,600 16 McArthur 157,000 157,000 kk *Sierra Valley 219,800 138,100 Lahontaji Drainage Basin 68 ■*Surprise Valley 277,900 119,300 69 ■^Madeline Plains 14-66,800 36,000 70 *Eagle Lake 1^,600 40,100/ 20,500iv 71 •ifwniow Creek in, 900 72 *Secret Valley 57,500 41,000 73 *S\isajQ River 215,200 118,900 71^ *Herlong 2l44,0OO 27,200 * Efcrdrographic units in which probable ultimate water requirement would be limited by available water supply. a/ Data extracted from Tables 53 and 55, Department of Water Resources "Bulletin No. 58." b/ Limited probable ultimate water requirement for Willow Creek hydrographic unit of 41,900 acre-feet shown in "Bulletin No. 58" was a typographical error. Correct value is 20,500 acre-feet. .2^ CHAPTER II* GEOLOGY AKD HTDROLOGY The geologic sispects of a ground water basin and the hydrology of the area provide the basis upon vhich evaluations of the ground water conditions of each basin have been made. This chapter discusses the elements involved in description and evaluation of ground water basins. Chapter IV presents the description and evaluation of each ground water basin investigated. Geology; A Frmdamental Part of Ground Water Studies Ground water exists at many places beneath the surface of the earth. It is usually hidden from view but frequently can be seen flowing from springs and wells or seeping into tunnels. Certain properties of geologic materieils control the ability of ground water to enter into, move through, be stored in, or be extracted from the groxmd. Therefore, em understanding of the geology of the Northeastern Coxinties Is necessary to gain an understanding of the ground water foiand within the basins investigated. Furthermore, an explanation of geologic concepts and terms used is necessary for complete understanding of much of "this report. Geologic Formations A geologic formation is a fairly widespread groitp of rocks related in origin, age, and composition. Only a few formations in Northeastern CsLLifomia have been named due to a lack of previous geologic study of the area, but the remaining materials can be subdivided on the basis of age and composition. The discvussion of the geologic formations of Northeastern California beginning on page 5© indicates for each formation its map symbol and describes its general location, extent, physical character ist ice, and water-beeiring -27- characteristics. For the purpose of this report, the rocks have heen divided into three main groups: basement complex rocks of pre -Tertiary age, volcanic rocks of Tertiecty-Qiiaternary age, and sedimentary deposits of Tertietry-Quaternary age. A discussion of the importeuit water-hearing features of each geologic unit is contained in CSiapter IV for each ground water basin studied. Also included in Chapter IV are stratigraphic columns for each basin. The stratigraphic column presents the various geologic units found in the basin and is arranged in chronologicetL order. Ihe colimin includes a summary of the physical and water-bearing properties of each geologic unit or formation. Table 7 shows the areal distribvrtion of the vario\iB geologic units and their relative water-bearing importance. Geologic Structure To the average person, the rocks making iip the crust of the earth appear to be solid and nearly unbreakable. However, the crust is actually somewhat plastic, ^is is demonstrated by the forces which slowly bend and squeeze the bedrock upward into folds called anticlines ( ^) and downward into folds called synclines ( w ). If conditions are such that folding cannot relieve the strain, then rupture and movement accoopanied by an earthquake occxirs along a plane called a fault. Ibe movement may be in either a horizontal or vertical direction or a combination of both. During movement, the materials along the fault sometimes become grotind up into a mass of clay called gouge. If the rock is hard and brittle, no gouge may develop and the fault zone becomes filled with rubble. If vertical movement along a fault creates a cliff, it is called a fault scarp. -28- TABLE 7 DISTRIBUTION AND WATER-BEARING IMPORTANCE OF GEOLOGIC UNITS IN NORTHEASTERN CALIFORNIA Ground Water Basin ] GEOLOGIC UNIT 3E >- 1/1 in < =) 1- _!■ < >- UJ ^i < Q > z CQ 0£. -D c >- LU _J _l < > > _) _i < u. >- LJ _l _J < > ai LU 8 o >- LU _i _i UJ < >- LU Z o t/1 z < -J Q. LU Z _I LU O ii so - LU _J _i < > Q. oc Z3 C >- oc > S UJ Ij 1^ SEDIMENTARY ROCKS (Qsd) (Qs) (Ql) (Qls) (Qta) s S M s Sand dunes Sand and silt deposits Recent lake deposits Landslides Talus Muck and peat deposits Basin deposits INTERMEDIATE ALLUVIUM ALLUVIAL FANS Terraces (Omp) (Qb) (Qal) (Qf) (Qt) s M L s M M M M s M L M s M L M M s M L M s M L S M M NEAR -SHORE DEPOSITS PLEISTOCENE AND LAHONTAN UKE DEPOSITS Glacial outwash Moraines (Qps) (Qpl) (Qpo) (Qpm) M M M L L L M S M L M s L S* ALTURAS FORMATION BIEBER FORMATION PLIOCENE LAKE DEPOSITS Forty-nine Camp formation Deep Creek conglomerate (TQo) (TQb) (Tpl) (Tmfc) (TiDdc) L M M* M* M M* M* M M Auriferous gravels Gold Run sandstone Fort Sage sandstone VOLCANIC ROCKS RECENT BASALT Cinder cones PLEISTOCENE BASALT Pleistocene pyroclastic rocks PLIO- PLEISTOCENE BASALT (Teg) (Tgs) (Tfs) (Qrvb) (^ (Qpvb) (Qpvp) (TQvb) M M L L S L L L S* S L M L L L M L L L Plio-Pleisfocene pryoclastic rocks Worm Springs tuff Pliocene basalt Pliocene andesite Pliocene pyroclastic rocks (TQvp) (TQvt) (Tpvb) (Tpvo) (Tpvp) S S M s M Rhyolite Miocene volcanic rocks Miocene basalt Miocene andesite Miocene pyroclastic rocks (Tvr) (Tmv) (Tmvb) (Tmva) (Tmvp) s s s M Big Valley Mountains volcanic series Turner Creek formation Cedarville series Sierron volcanic rocks Sierron basalt (Tvb) (Tmtc) (Tmc) (Tsv) (Tsvb) s s M s S* s s Sierran andesite Sierron pyroclastic rocks BASEMENT COMPLEX Granitic rocks Metamorphic rocks (Tsva) (Tsvp) (JKgr) (pKm) S NOTE : Principal water yielding units are indicated by bold face type. L - May transmit or yield large amounts of ground water. M - May transmit or yield moderate amounts of ground water. S - May yield small quantities of ground water, generally sufficient only for domestic or stock uses. - Yields little or no ground voter. * - Water bearing importance restricted to areas away from valley floor. Northeastern California is an intensely faulted area. At least four major faults and numerous lesser ones occur in the area. Some of these faults stretch for many miles and several have up to 7,000 feet of vertical displacement. The faulting has broken the crust of the earth into huge, uplifted mountain ranges flanked by low-lying valleys. The faults characteristically present bold, jagged scarps which can be seen for miles as they bound one side of a mountain or moiantain range. The most notable faxilt block mountains, large masses of rock that have been pushed bodily upward, are the Waamer and Diamond Mountains. Surprise Valley and Mohawk Valley are relatively narrow trenches botinded on the two longer sides by nearly paj:«llel faiilts. Folding on a regional scale in Northeastern California is of less significance thaji is regional faiilting. There is one series 6f northwest trending anticlines and synclines in northern Lassen and southern ^fodoc Counties. Synclines form Big Valley and the Alturas Basin, with anticlines occurring in the Intervening areas. Neither the synclines nor the anticlines are simple folds. The large syncllne in the Alturas Basin has been faulted and also contains several minor anticlines and synclines. The major anticlinal areas have been further favilted and tilted, so that now the tilted fault block structture is predominant. The Geologic tfeip One of the phases of a study of ground water geology is the compilation of a geologic map showing the surface expos\ires of the various formations. Through the combined use of the geologic map and the geologic sections, a three dimensional geologic model of an area can be visualized. (See geologic maps and sections listed under Plates.) -30- The varioiis formations are designated on the map by letter symbols. Each symbol contains letters representing the eige and either the rock type or the format! onal name. For example, Pleistocene beisalt is designated by the symbol "Qpvb." The first two letters stand for the age of the material, in this case Quaternary period and Pleistocene epoch, the third for volcanic rocks, and the last for basalt. The Relationship Betveen the Geologic Materials and Ground Water Neaxly all of the materials that make up the surface of the earth have oi)en spaces vhich may contain ground water. The size of these openings ranges from minute pores in clays and small fractures found in many consoli- dated rocks to large lava tubes found in some basalt flows. The porosity, or percentage of the total volume of a material occupied by voids, is not necessarily indicative of the ease with which groimd water can move through the material. If the openings are very small, or are not connected, the material is said to have a low permeability even though its porosity may be high. Thus materials of low permeability and high porosity such as clay and t\jff transmit very little water. In contrast, materials of high permeability but somewhat lower porosity can yield large amounts of ground water. Materials of this latter type include fractured basalt and mixtirres of coarse gravel and sand. A geologic formation or part of a formation which readily trans- mits groiind water (i.e., has high permeability) is called an aquifer. In contrast, materials which contain ground water but do not transmit extract - able quantities (i.e., have low permeability) are called aquicludes. Certain rocks, such as non-fractured granite, neither absorb nor transmit water as they are practically impermeable; a rock of this type is called an aquifuge. All geologic fonnations can be classed either as aquifers, axiuicludes, or -31- aqulfuges. However, certain formations may act as an aqiilfer In one area and an aqvildude In another area because of changes In permeability resulting from changes In pbyslcal characteristics of the materials. J Underground vater Is present In tvo major zones beneath the grovind surface. Flgui*e k shows the occurrence of ground water within these zones. In the upper zone, or zone of aeration, most of the openings In the geologic materials are filled paxtly with air and partly with water. An exception Is In the subzone of soil water where conditions approaching saturation may exist due to lnflLti«,tlon of rainfall or water used for Irrigation. Another exception Is In the capillary subzone which extends from the under- lying water table up to the limit of capillary rise of water. Wells cannot produce ground water from the zone of aeration. Vflaere perched ground water occtirs, It Is contained In an Isolated saturated zone separated from the main body of grovmd water by an underlying Impermeable stratum. Well "B" on Figure 5 represents a well producing from perched groiind water. In the lower zone, or zone of saturation, all of the Interconnected openings In the geologic materials are filled with ground water. Ground water exists In this zone tinder unconflned or confined conditions, or \mder a condition Intermediate between the two. An iinconflned aquifer Is not overlain by Impervious materials, and contains water In Interconnected open- ings In the zone of saturation. The water table is the upper stirface of an unconflned body of ground water or approximately the level to \riilch water will rise in a well tapping xmconfined ground water. Well "D" on Figure 5 represents a well located in an unconflned aquifer. Unconflned ground water flows in the direction of the downward slope of the water table. A confined aquifer contains ground water overlain by material sufficiently impermeable to Isolate the aquifer from overlying aquifers -32- Figure 4 OCCURRENCES OF GROUND WATER Confinad Aquifer Figure 5 UNCONFINED AND CONFINED GROUND WATER 33 except in areas of recharge. Confined ground vater moves through an aquifer under pressure. The level to -vrtiich confined ground vater will rise in non- pumping wells is the piezometric surface. This surface is a representation of the pressure exerted by the confined ground vater on the materials enclosing the confined aquifer. When the piezometric surface is below ground, the water level will rise to some point, as represented by Well "A" on Figure 5. If the piezometric surface is above ground, the well will flow as represented by Well "C". The stratification of aquifers and aquicludes is the result of deposition under different environments. Coarse-grained deposits, saind and gravel, are laid down principally by streams, and are coarsest at the apex of alluvial fans nearest the mountains. Silts and clays are deposited where streams flood over areas surrounding active channels. Deposition in alluvial basins and in lakes is also principally of fine material, except that near- shore deposits are frequently sajidy. As environmental conditions have changed in the geologic past, due to changes in climate, faulting, and folding,^ the type of deposition has changed and variation in stratification is the result. The Ground Water Basins A ground water basin consists of an area underlain by permeable materials which are capable of furnishing a significant vater supply; the basin includes both the surface area and the underlying permeable materials. Ground water basins are separated from each other, or may be subdivided into groimd water subbasins, by the following features and conditions, listed in approxljnate order of desirability as boixndaries: nonwater- bearing rock, constriction in permeable materials, faxilt, zone of low -31^- permeability, topographic ridge, shoreline of a lake, or ground water divide. The various grovmd vater basins \rtiich are the subject of this Investigation are listed in Table 8. Hydrology; From Precipitation to the Well The initial soijrce of nearly all ground vater is precipitation. Some precipitation innnediately infiltrates into the ground, but the re- mainder becomes runoff and collects in streams and rivers. This surfax:e flow may be used for many purposes or stored for subsequent Tise. The runoff restilting from precipitation usually has seveiral opportunities to beccane ground water. The pattern of movement of a drop of water from the time it enters the ground to the time it emerges either naturally or by pumping from a well is controlled by the subsurface conditions encountered. Upon entering the ground, the water moves downward throxogh the zone of aeration and into the zone of saturation. This happens -vriienever water from precipitation, streamflow, applied irrigation water and all of the varioxis other sources, moves into the ground through the open spaces in permeable materials. The area over which this is accomplished is called the recharge area. These areas are foiind on mountains, along foothill slopes, and on valley floors. Important recharge areas often occur in alluvial fan and stream channel deposits below the mouths of canyons. Here the deposits are usually very permeable, allowing for rapid infiltra- tion. In addition, water flows over these recharge areas dioring all, or at least most, of the year. Areas of younger volcajaic rocks such as highly fractiored lava flows constitute smother important type of recharge area. In this case, the major portion of the precipitation infiltrates and only a minor portion produces streamflow. ■35- TABLE 8 GROUHI) WATER BASINS Ground vater bsusins (a) Plate showing areal geology Plates showing ground vater data and subbaslns Lines of : Potential Name : Number (b) equal : for elevation : development CENTRAL VALLEY DRAINAGE BASIN GOOSE LAKE VALLEY Willow Ranch Davis Creek Franklin Creek ALTURAS South Fork Pit River Valley Wazm Springs Valley BIG VALLEY ROUND VALLEY FALL RIVER VALLEY SIERRA VALLEY MOHAWK VALLEY HUMBUG VALLEY LAHONTAN DRAINAGE BASIN SURPRISE VALLEY Upper Alkali Lake Middle Alkali Lake Lower Alkali Lake MADELINE PLAINS Madeline Ravendale Dry Valley Grasshopper Valley WILLOW CREEK VALLEY SECRET VALLEY 5-1 ( 5-1.01 ( 5-1.02 ( 5-1.03 ( ( 5-2 5-2.01 5-2.02 5-U 5-36 5-5 5-12 5-11 5-35 6-1 ( 6-1.01 ( 6-1.02 ( 6-1.03 ( HONEY LAKE VALLEY 6-2 ( 6-2.01 ( 6-2.02 ( 6-2.03 ( 6-2.01^ ( 6-3 6-63 6-if ( 21 2k 27 30 k 5 10 11 12 13 11* 15 16 17 18 19 20 22 25 28 31 23 26 29 32 (a) Capitalized names are basins. Uhcapltallzed are subbaslns. Groupings are arranged In order of discussion In text. (b) Department of Water Resources numbering system for ground water basins. -36- Water vhlch peisses downvard through a permeable material eventiially reaches a zone of saturation. This zone contains vater under hydrostatic pressure. Under nattiral conditions, vater vmder hydrostatic press\ire moves laterally toward eo^as of pressure relief, such as springs. In causes vhere the pressure relief area Is a stream channel, springs often form along the channel and help to maintain streamflov during low precipitation periods. If a ground water basin Is ccmpletely surrounded by Impermeable materials and has no surface outflow, ground vater movement may terminate In upward seepage to the sxirfeice In the lowermost portion of the basin. If a stream flows through and out of the basin, ground vater movement may originate or terminate at this stream. Development of veils In a ground vater basin diverts some or all of the nat\iral discharge of the ground vater to artificial discharge through veils. The general ground vater movement pattern of a valley can be interpreted from maps vhlch show lines of equal elevation of the groimd vater surface. From such a map, the direction of ground vater movement Is Interpreted as being perpendicular to the contour lines and moving from the higher elevation contour to the lover. The relative spewing betveen the contour lines Indicates the hydraulic gradient of the ground vater, frtilch Is sin Index of the resistance encoimtered as the vater moves through the various permeable materials. Other physical baxrlers vhlch impede the movement of ground vater are also Indicated by the patterns or spellings of the ground vater contours. The effect of faults on the movement of ground vater ccui often be Interpreted from the contour maps. Where faults have rejosltloned a particular vater-bescrlng stratum opposite an Impermeable stratum, gro\md vater may rise along the fault zone and appear at the ground stirf ace as springs . If the groimd vater has percolated deep -37- enough to become heated and mineralized. It vlll appear at the siirface as a hot spring. Well Yield; A Function of Geology and hydrology The Interrelationship of m£uiy geologic and hydrologlc factors must be known to predict the yield of a well proposed for construction. Some of the more important factors axe: the type, depth, and extent of the various subsurface materials; the trajasmissibillty of the various aquifers; the relative locations of the aquifers and the aquicludes; the extent said permeability of the rechaxge areas; and the availability of water for recharge. When these and other faxitors are evaluated, an opinion of the ground water development potential of an area can be made. Proper construction and development methods must be utilized in order to obtain the pptlmum ground water yield from a well. The two most cOTmon methods of drilling an irrigation well are either by using a cable tool rig or a rotaxy rig. The choice of method is often dependent upon the geologic materials that are expected to be encountered. The cable tool method employs a string of tools suspended from a cable. A bit, alternately raised and dropped, breaks up the material at the bottom of the hole. The broken material is removed from the hole at intervals by a bailer. This method of drilling is frequently tised in hard, broken materials such as burled lava flows. The second method is the rotary. This method employs a rotating cutting head. Cuttings are removed by mud-laden drilling fluid which is pumped down through the drill pipe, and then rises to the surface in the space between the drill pipe and the wall of the hole. The rotary method is often used for drilling through bedded sedimentary materials. -38- After the well has been drilled, steel pipe casing is usually installed. By selectively perforating the well casing, water can be drawn from the desired aquifers and any subsurface strata yielding poor quality water can be sealed off. The well should be properly developed in order to produce the maximum amoiint of water with a minimum of drawdown. Complete and proper development will also reduce sanding, if it is a problem, and lengthen the economic life of the well. Development usually consists of introducing rapidly moving water into the materials surrounding the well and then reversing the flow. This procedure sorts the geologic materials and results in the removal of fine materials near the casing. After a well has been developed, a surface seal is usually placed aroimd the casing. Ihis seal prevents any ixndesirable surface water from flowing into the well. Furthermore, after the pump has been installed, a well intended for domestic use should be adequately chlorinated. Water Qixality Ground water may be available in abundaxit quantity but if it is of unsatisfactory quality it may be useless. Water may be unsuitable for beneficial use due to excessive dissolved mineral content. It may have excessive temperature or contain objectionable bacteria and be unfit for use. Bacterial contamination and hi^ temperature are temporary water qxiality hazards which can usually be corrected readily by treatment or storage. However, problems associated with dissolved minerals iisually cannot be easily corrected and therefore mineral criteria have been used in our evalua- tion of the suitability of water for beneficial xise. Water is an excellent solvent capable of dissolving many minerals and gases. Most of the dissolved substances are in solution as electrically charged particles called ions which can usually be identified and their -39- concentration measured. When certain of these constltxients are present In water In high concentrations they make the vater unsuitable for particular beneficial uses. For example excessive sulfate and chloride Ion concen- trations In Irrigation vater may prevent plants from obtaining needed molstxire and nutrients from the soil. These damaging effects can resxilt In reduced crop yields or conrplete loss. Mineral analyses of ground vater samples from the Northeastern Counties vere made to determine the suitability of the ground vater for a^lcultural and domestic use. These analyses Included determinations of four cations, namely, calcium, magnesium, sodium, and potassium; and six anions, namely carbonate, blceurbonate, chloride, sulfate, fluoride and nitrate. The boron auad sUlca content vas determined. The pH value and electrical conductivity of each vater sample vas measured and hardness vas also computed. Measuring the Hazard In Inrlgatlon Water No rigid criteria for Irrigation vater quality can be established becaxise there exe so many factors vhlch affect the damage that excess of a mineral constituent can cause. Some of the more Important of these factors Include climate, frequency of Irrigation, stage of plant grovth, tolerance of the plant, type and texture of the soil, drainage, and use of soil additives . General criteria, >rtilch are quite viseful, hovever, have been developed based upon average climatic conditions, soil propeirtles and normal Irrigation practices. A study of the vater quality data from Northeastern California as related to these criteria has Indicated that only a limited number of the ground vater constituents are present In hazardous concentratlc -1^0- We have evaluated these problem constituents on the beusis of the following criteria. Total Dissolved Solids . "Bxe term total dissolved solids refers to the total amount of the various mineral constituents in solution. An excess of total dissolved solids can among other things ^ limit the avail- ability of moistixre to plants and require more frequent irrigation and more intensive soil leaching. The electrical conductivity of water is readily determinable suid is a convenient indicator of this salinity hazard. Nearly all irrigation waters which have been Msed successfully over a long period of time in California possess en electrical craiductivity of less than 2,250 micronhos per centimeter and in most caises it is less than 73O microoihos per centimeter. This latter conductivity value is used, in this bulletin as the demarcation of salinity hazard. Sodium . When irrigation waters containing high concentrations of sodivmi ion are utilized, they can result in the buildup of sodiinn ion in the soil solution and can modify the soil structure. This will result in poor aeration of the soil, lew infiltration rates, and a decrease in the available moisture to plants. In addition, sodivun ion may replace calcium ion in the root tissues, resulting in a calciim deficiency which may kill the plant. A nttmerlcal value ^diich can be used as an index of sodium or al k ali hazard of water is the sodium-adsorption-ratio, referred to as the SAR* value of water. Irrigation waters possessing SAR values of less than 10 and electrical conductivities of less than 75O micromhos per centimeter are considered to be relatively free of sodiiom hazard. All waters with SAR values greater than 10 are considered to contain some sodium hazard and should be used with care. ♦ SAR s» Na Constituents axe expressed in ^_^__^^^^ equivalents per million. /Ca-^ + Mg-^ -in- Boron » Very low concantratlons of boron are essential for plant grovth; however, irrigation waters with horon concentrations greater than two parts per million axe considered to possess a boron hazard. Excessive boron can cavuse leaf bvcm, prematixre leaf drop, and reduced crop yields. Waters containing concentrations between one -half and two parts per million may be hazardous to specific plants. Hazards in Domestic Waters Criteria for domestic waters are generally more stringent than those for irrigation because public health is involved. Both the IMlted States Public Health Service and the State Department of Public HeeuLth have established certain standards for drinking water. Some of Ifae mineral con- stitvients of water which are inclvided in these standards have been identified in hazardous concentrations in waters from the northeast counties. They include arsenic, fluoride, iron, and nitrate. Arsenic . Small amoiants of arsenic are found in body tissue but in excess it is considered toxic to man. Concentrations exceeding 0.05 parts per million are considered to be hazardous in drinking water. Fluoride . Excessive concentrations of fluoride ion may cause mottling of teeth and dama^ to bone structure. Biere is increasing evidence that the threshold concentration of fluoride in water for barely detectable mottling of teeth varies with the mean annual air tenrperature and htmiidity. ahe threshold is indicated to be about 0.5 - 0.7 parts per million in warm dry climates while in colder regions the threshold is 1.0 - 1.5 parts per million. Under the prevailing climatic conditions, concentrations over 1.3 parts per million are considered to be excessive within the areas of use in the northeast counties. -1^2- Iron . Trace amoimts of Iron are essential to nutrition and concentrations found in the ground vaters of the Northeastern Covmties do not constitute a hazcurd for physiological reasons. However, waters con- taining dissolved iron in excess of 0.3 parts per million are considered to he unsuitable for domestic use as they can stain laundry and porcelain fixtures, and may detrimentally affect the taste. Nitrate . High concentrations of nitrate ion in irrigation waters can be very beneficicuL to plant life. In domestic waters, however, excessive nitrates are considered as a possible cause of a disease in infants. This diseeuse is characterized by insufficient aeration of the blood. For this reason concentrations of nitrate ions exceeding h^ parts per million in domestic waters are considered to be hazardous. ■k3- ''•^^S^^tfr.' ii^^V- :, S»r< ;*s«- Warner Mountains, west of Surprise Valley ^ater may fall as snow along rugged mountain slopes of the Northeastern Counties or as rain on eroded escarpments of barren plateaus. It may nourish stands of virgin timber or evaporate from the burning surface of alkali flats. Hays Can/en Range, east o^ Surprise Valley Wmdel Fan, Horn/ Lake Valley Melting snows feed mountain streams which wash silt and stones downslope and spread them In fan-shaped deposits where the canyons widen into broad flat valleys. Much of the water sinks into permeable deposits and percolates into aquifers which extend beneath the valley floor. Coon* moferio/ depotited by Owl Creek, west of Surprite Valley Goosm Laka, Warner Movnfains in fhs background Some Streams drain into broad lakes, shallow and valley bound, from which the waters rarely spill. Others form rivers i^ich meander through farmland and forests, flow quietly past the valley towns, contribute water to the aquifers, and continue to the sea. Fall Rhrar A4i7lt, Fall Rivar in foregrounif. Pit Kivar above ■//-^ Sood cut west o^ Fat/ RiVer Mills Within upland areas where flowing lavas have cooled and crumbled and faults have fractured the crust of the earth, the water may sink rapidly into the ground. Devils Garden, southwest of Goose Lake •■^■JinTf, ?3>*tK ^If.,?^— ,^,. ._^ _ -'■^*it' ;^^^; ^jliich has a uniform easterly dip, suggesting that it may extend beneath the floor of Big Valley where its depth would be several thousand feet. The Big Valley Mountains volcanic series has a low overall per- meability. Hence, it is considered to be of little importance to ground water. However, there may be local permeable zones which could yield suffi- cient water for domestic or stock purposes. Miocene Volcanic Rocks (itav, Itovb, Bcva, Pnvp) . Miocene volcanic rocks occur in many areas north of Madeline Plains. In most of the cureas studied, the Miocene volcanic rocks have been divided into basalt, andesite, and i>yroclastic rocks. The Miocene basalt (Ttovb) is a dark-colored lava containing occasional fracture and scoria zones. It frefuently occurs as tilted lava XO.ateaus up to several hvuidred feet in thickness. The basalt is found along the crest of moiintains, such as at Eagle Peak, and also at low areas such as along the east side of Suirprise Valley, thus indicating a great amount of fault movement since the basalt flows were eitrplax:ed. Areas of Miocene basalt frequently have a niimber of faults crossing them. These faults may interrupt the continuity of the fracture and scoria zones, thus affecting the flow of ground water along these zones. In general, the Miocene basalt rsmges from low to moderate permeability. Where located within the zone of satiuration, it may yield moderate amounts of water to wells . -53- Miocene andesite (Dnva) occ\irs in the Warner Mountains and at a few other localities. It is more massive than the basalt as it frefuently occxirs £U3 short, stubhy flows or as plugs and domes. As it is relatively impermeable, it is of little significance to ground water. Miocene pyroclastic rocks (Tmvp) outcrop to the northeast of Madeline Plains and also in the Warner Mountains. The rocks may be corre- lative to similar rocks found in the Turner Creek formation and consist of dark-colored mudflows and beds of pale-colored tuff. Included in this group are a few beds of sandstone axid diatomite. In general, the Miocene pyroclastic rocks are of low permeability and thus of little importance to ground water. Some of the sandstone beds, however, may be sufficiently perme- able to provide limited amounts of ground water to domestic or stock wells. Rhyolite (Tvr) . Rhyolite of Miocene to Pliocene age has a wide- spread distribvrtion in the area studied; however, the total area of rhyolite outcrops is quite small. The rhyolite is a pale-colored, massive to Jointed rock; it occasionally contains zones of black to brown obsidian. The rock usually occurs as plxigs and domes, but on occasion may occur as sills within older rocks. As rhydite is essentially impermeable, it is of little importan to ground water. Pliocene Volcanic Rocks (Tpvb, Tpva, Tpvp) . Pliocene volcanic rocks occur north smd west of Willow Creek Valley. The ELiocene volcanic rocks are divided into basalt, andesite, and pyroclastic rocks. Pliocene basalt (Tpvb) is gray-black in color and contains a few permeable scoriaceous zones along the top and bottom of individual flow i units. In addition, the basalt also contains some vertical Joints which I form permeable paths connecting the various scoriaceous zones and render i the basalt moderately permeable. Some of the precipitation falling on the -5^ basalt seeps downward along the joints and then mo-ves laterally along the scorlaceous zones. Pliocene basalt, vhere sufficiently recharged, yields moderate qiiantitles of ground water to wells. Pliocene andesite (Tpva) occiirs at widely sepaxated areeis as plugs and short, stubby flows. The rock is massive to platy, essentially impenne- able, ajid unimportant to ground water. Pliocene pyroclastic rocks (Tpvp) consist of mudflows and beds of tuff. The rock is quite massive, essentially impermeable, and of little importance to groxmd water. Plio-Pleistocene Volcanic Rocks (TQvb, TQvp) . Basalt £uid tuff of Elio-Fleistocene age occur in widely separated areas from Honey Lake Valley north to the Oregon state line. The basalt (TQyb) makes up the cones of old ELio-Fleistocene volcanoes such as Snowstorm, Shinn, Shaffer, and Tule Mountains. It also occurs as sloping plateaus in the Altureis Basin and in Goose Lake Valley. In the latter area, the basalt is about 500 feet in thickness. Individual flows in the basalt range from 10 to 80 feet in thickness, and are separated by highly permeable zones of scoria up to 20 '^. feet in thickness. Each flow has been broken by Joints and fractures caused by cooling of the lava and by folding and faiilting. Occasional beds of silt, clay, diatomite, and tuff up to 50 feet in thickness are also present. The breaking and fracturing of the basalt flows and the presence of scoria zones have resulted in the creation of many permeable paths for ground water movranent. Much of the precipitation which falls on the Plio-Pleistocene basalt 8eex>s downward and laterally toward the sediments in the adjacent valley aji^as. Ground water movement in the basalt is illustrated in Figure 7. The basalt is moderately to highly permeable and where stiffi- ciently recharged probably would yield moderate to large quantities of water to irrigation wells. In areas where the basalt flows are interbedded with -55- '*t^«^*44JUJ«u Vorticol Joints Baked Cloy Zone Figure 7. DIAGRAMMATIC SECTION OF TYPICAL BASALT FLOW less penneable valley sediments, the basalt contains confined groiind -water. Irrigation wells tapping these buried lava flows may yield large quantities of ground water. Minor areas of ELio-Pleistocene tuff (TQvp) occTir in a few basins. It is of little Importance to ground water. Warm Springs Tuff (TQyt) . Extensive ELio-Pleistocene pyroclastic rocks occur in the Alturas Beuain, and are named herein the Warm Springs tuff member of the Altiiras formation. The rock is made up of a sequence of from 100 to lj-00 feet of gray to brown, massive pumice lapilli tuff, light-colored ashy sandstone, and resistemt rimrock areas formed by basalt-like welded t\iff . One of the distinguishing charswiteristics of the Warm Springs tuff is the ntmierouB c himn ey rocks caused by weathering of the massive ash flow t\iff . .56- In general, the permeability of the Warm Springs tuff is fairly low; hence, it would not yield large quantities of water to weHs. However, some of the seuidstone beds and zones of fractured, welded t\iff , where suffi- ciently recharged, may provide moderate quantities of water to domestic or stock wells. Pleistocene Volcanic Rocks (ermeable; however, there may be a few zones which could yield small, quantities of water to wells. Gold Run Sandstone (Tgs) . A semi-consolidated, poorly cemented sandstone and shale occurs along Gold Run Creek. This sandstone, named herein the Gold Run sandstone, is of early Tertiary age and of unknown thickness. The permeability of the Gold Run sandstone appears to be low. However, it may yield small amounts of water to wells. Auriferous Gravels (Teg) . River gravel deposits of Eocene age occur in the mountainovis area southwest of Honey Lake Valley. The deposits are of low to moderate permeability auid consist of semi-consolidated gravel, sand, and clay, in pert gold-bearing. Auriferous gravels yield small amounts of ground water to many springs, but becaoise the deposits are located only at higher elevations, they are uninrportant to ground water in Honey Lake Valley. ■59- Deep Creek Conglomerate (l)6dc) . A conglomerate of QLigocene to Miocene age outcrops along the vestem side of Surprise Valley, at the foot of the Warner Mountains. The conglomerate, named herein the Deep Creek conglomerate, is composed of vestvard-dipping heds of massive, consialidated conglomerate separated by beds of shale, mudflows, ajad tx>ff. The rocks are essentially inrpenaeable and of little importance to grovmd vater. Forty- Nine Camp Formation (ihifc) . The only recognized outcrops of the Forty- nine Camp formation are to the northeast of Surprise Valley. The formation consists principally of Miocene sandy txiff and volcanic gravel. It may be a sedimenteiry phase of the more widespread CedarviUe series. In its outcrop area, the Forty-nine Camp formation is about 750 feet thick and dips gently to the west. It is overlain by Miocene basalt flows. Certain beds of the Forty-nine Camp formation appear to be mod- erately permeable Gind may provide moderate quantities of ground water to irrigation wells. Recharge to the Forty-nine Camp formation is from precipitation falling on the area between Surprise Valley and Long Valley in Nevada. Pliocene Lake Deposits (Tpl) . Bedded lake deposits of Pliocene age outcrop in Honey Lake Valley, Secret Valley, and several other valleys. The greatest accxmrulation is in Honey Lake Valley, where the deposits are neatrly 5, OCX) feet thick. The Pliocene lake deposits generally consist of bedded consoli- dated sandstone, siltstone, and diatomite. The deposits in the vario\is valleys are probably of equivalent age, having been deposited during the Pliocene ei>och. -60- The vater-bearing characteristics of the Pliocene lake deposits are largely uiilmown. It appears that the deposits in general possess only- low to moderate permeability and thus would be able to provide only relatively SBiall to moderate quantities of confined ground water for limited irrigation purposes. Olie deposits usviaUy should provide stiff icient water for domestic or stock purposes. A few areas of Pliocene lake deposits are composed of near-shore sand and gravel. These latter areas could provide somewhat greater amounts of ground water for irrigation purposes. Alturas Formation (TQa) . Plio-Pleistocene lake deposits in the Alturas Basin belong to the Alturas foxmation. The formation consists of two nearly identical sedimentary members separated by a Plio-Plelstocene bcutalt member and the Warm Springs tuff member. The lower and upper sedi- mentary members consist of flat-lying, light-colored sandstone, gravel, diatcmite, and tuff, having a total thickness of about 800 feet. The lower neiBber is believed to be underlain by basalt emd rocks of both the Turner Creek formation and the Cedarville series. The lower and upper members of the Alturas formation are the principal water- yielding materials in the Alturas Basin. Beds within the two members range in permeability from moderate to high, contain both semi- confined and confined water, and provide abundant water to irrigation wells. Bieber Formation (TQb) . Most of the lake deposits in Big and Round Valleys belong to the Bieber formation of Plio-Pleistocene age. These deposits are ccmposed of interbedded gravel, white sand, black sand, clay, silt, and diatcsnite. They are estimated to be at least 1,000 feet thick and sure probably underlain by similar materials belonging to the Turner Creek formation. -61- The Bieber foimation is moderately permeable and yields moderate amounts of ground vater to n\mierovis domestic and irrigation veils. The best producing zones appeeir to be the white sands and the black sands. However, the main difficulty in developing the sand zones is that they cure usually very thin and are separated by less permeable zones of clay, silt, and diatomite. Moraines (Qpn) . During the Pleistocene ei)Och, hxige masses of ice covered the crest of the Sierra Nevada ajxd the Warner Mountains. These slowly moving glaciers cajrved broad basins into the xtx:k. The Lakes Basin in the Sierra Nevada is an example of such a glaxiial-carved feature, and today it gives mute evidence of the relentless grinding and polishing action of the glaciers. The great volumes of rock that were removed from the mountains were transported by the glaciers downsloi)e. When the glaciers melted, they dropped their rock loads in the form of moraines. These moraines are exposed today along the west side of Mohawk Valley, eind at scattered localities in the Warner MountedLns. The moraines are composed of a slightly consolidated mixture of boulders, cobbles, sand, and rock flour. Permeability of the moraines is generally low; however, a few springs issue from the deposits confirming the presence of a fev permeable zones. Glacial Outwash (Qpo) . While the glaciers were melting, great torrents of water were cascading down the mountains csurrying rocks and sand into the adjacent valleys. This material fozmed the outwash deposits that are now found along the west side of Mohawk Valley. These outwash deposits appeeu: to be moderately permeable ajid locally may yield moderate amovints of ground water to wells. A few zones in the outwash deposits are probably highly permeable and may yield large amounts of gro\md water to wells. -62- Pleistocene and Labontan Lalce Deposits (QpOl) . Lake deposits of Pleistocene age are found in Pall RLver Valley, Madeline PledJis, and tlie Sierra Valley-Mohawk Valley area. Lake deposits also occur In Honey Lake Valley where they are called Lahontan Lake deposits. The Pleistocene lake deposits are made up of bedded blue-gray sUt, clay, and lesser aino\mts of sand. The deposits may be up to several thousand feet thick. Interbedded with the materials are a few lava flows and occasional beds of dlatomlte and volcanic ash. Most of the lake deposits pi^bably grade downward to older lake deposits of Pliocene a^e. Moderate permeabilities are characteristic of the Pleistocene lake deposits in Fall River Valley and Madeline Plains. This, along with the presence of alkali and high concentrations of dissolved salts in the ground water, frequently makes the deposits in these aareas of little direct valtie as a source of ground water. Pleistocene laJae deposits in Sierra and Mohawk Valleys are moderately to highly permeable and yield moderate to large quantities of water to wells. In Honey Lake Valley, Pleistocene lake deposits were foimed on the bottcm of Lake Lahontan. These deposits, althoiigh generally similar to the previously described Pleistocene lake deposits, have extensive sandy zones that are moderately to highly permeable. Consequently, these deposits constitute the most important aquifer in Honey Lake Valley. The Lahontan lake deposits often provide leurge quantities of water to wells located in the southesistem and northwestern portions of Honey LeJce Valley. Near- Shore Deposits (Qps) . Near-shore deposits, of Pleistocene age, flrequently are associated with both the Pleistocene and the Lahontan lake deposits. 15a.e near-shore deposits were formed at the same time as the lake deposits and differ from them only in composition and permeability. The two types of deposits generally interfinger. -63- Neair-shore deposits were fozmed along teachee, terraces, and deltas surroxmdlng the lakes idilch once occupied the valleys. The deposits consist of hedded, poorly consolidated gravel, sand, silt, emd clay. Ihey are usually not over 300 feet In thickness, bxxt they may extend laterally beneath the lake deposits to the lowest point in the bedrock floor of the valley vhere they may be several thousand feet thick. The near-shore deposits generally are of moderate to high pezne- ablllty. The presence of occasional cemented zones and beds of silt and clay tend to confine ground water to certain more pezmeable beds. In general, where the near-shore deposits are within the zone of saturation, they yield fair to moderate to large quantities of giound water to Irrigation wells. Terraces (Qt) » A few lake and stream terraces are located in Goose Lake Valley and Mohawk Valley. These deposits are of Pleistocene to Recent age and are probably not over 50 feet in thickness. The terraces are composed of poorly sorted gravel, sand, silt, and clay. Becavise of their small areal extent and moderate permeability, the terraces are only capable of yielding moderate quantities of ground water to shallow dcnestic and stock wells. Alluvial Fans (Of) . Alluvial fans of Recent age have formed at the mouths of meuiy canyons entering the valleys of Northeastern California. The fans are cooiposed of stratified gravel, sand, and silt, and in some ceuses may be as much as 1,000 feet in thickness. The alluvial fans frequently con- tain the principal aquifers In a valley. These aquifers are capable of yielding large quantities of confined and semi-confined water to wells. Alluvial fans also axe imoportant as recharge areas. IBals is demonstrated by the high permeability of the upper, bouldery portions of the fans. Wells located here may yield large quantities of unconfined ground water even -6i^- thOTigh the water table nay be fairly deep. The middle portions of the fans consist of a sandy and gravelly zone that Is somewhat less penoeahle, but still could act as a recharge area to a lesser degree. Wells located In this middle zone may encovtnter moderate to high quantities of both \inconflned and confined vater. The beds In this zone of the fcua exe discontinuous. Thus, there Is no certainty of finding a permeable bed at a specific point and specific depth. The lowermost portion of the fans are usually scmevhat less permeable but may contain pezneable sand beds vhlch could yield con- fined water. Like the middle zone, however, the beds In this lower zone also may be discontinuous. Hence, for this zone too, there Is the imcer- talnty of Intercepting beds at a specific location or depth. Figure 8 shows a longitudinal section along a typical fan and delineates the three water-bearing zones. FINE GRAINED ZONE (sond.sllt ond cloy) Generally of low ptrmtobillty, but often contains permeable tend beds whicti yield confined woter. MEDIUM GRAINED ZONE (grovel, land, silt and cloy) Moderately permeable, contains moderate to Itigh quontitles of unconfined and confined water. COARSE GRAINED ZONE (boulders, gravel ond sand) Highly permeoble, may yield lorge amounts of unconfined water. Important rechorge Oreo. Figures. LONGITUDINAL SECTION ALONG TYPICAL ALLUVIAL FAN -65- Intermediate Alluylxm (Qfil) . The toe euce&B of alluvial feuis merge Into alluvial plains coniposed of Intermediate alluvium of Recent age. The alluvlvun generally consists of unconsolidated sand and sUt with some lenses of gravel and clay. It Is us\ially not over 100 feet In thickness. In general, the Intennedlate alluvium Is only moderately permeable; however, lenses of coeirse material are present vhlch are capable of providing good quantities of ground water to shallow Irrigation wells. Basin Deposits (Qjb) . Basin deposits of Recent age occur In the flat, central portions of many valleys. The deposits consist of unconsolidat sUt, clay, organic laacls., and a few thin layers of fine sand. Some alkali ma be present. The basin deposits are usually not over 100 feet In thickness. The permeability of the basin deposits Is generally low and henc^ they yield only small amounts of water to shallow domestic and stock wells. Muck and Peat Deposits (Qprp) . Organic muck and fibrous peat occur In Jess Valley. The deposits are of Recent age and are currently being mined as a source of agricultural peat. The deixjsits are of very low permeability and of no Importance to ground water. Talus (Qta) . Accumulations of unconsolidated rubble form wedge- shaped talus slopes at the bases of many steep fault scarps along Pit River. These talus deposits, along with the faxilt zones with which they are related, provide vertical paths which may effect recharge of deep aquifers within adjacent sediments. Because the talus deposits are small in azreal extent and are mostly located above the water table, they are considered to be of minor importance as a direct source of ground water. Landslides (Qls) . Leurge landslides, of Recent age, have occurred at a few localities. The slides usually consist of a mixtture of rubble, clay sand, and crushed rock. Landslides are generally of low permeability and imlmportant to ground water. However, the landslides along the north side -66- of Honey Lake Valley appeaj: to be moderately permeable ajid locally yield moderate amounts of ground water to wells. Recent Lake Deposits (Ql) . Recent lake beds ajre found at Goose Lake, Eagle Lake, Honey Lake, the three alkali lakes in Surprise Valley, and at nmnerous other localities. The deposits consist of sticky, blue-black silt, clay, and organic muck; they also contain occasional stringers of salt, alkali, and fine sand. These laJce deposits range in thickaess from a feather edge to a possible maximum thickness of about 5^000 feet. While the deposits are of Recent a^e near the surface, mainy of them are probably Pleistocene and older in age at a depth greater than 100 feet. The overall permeability of the Recent lake deposits is very low. As a consequence, they apparently serve £is a barrier to both vertical and horizontal ground water movement. Furthermore, alkali, salt, and organic matter adversely affect the quality of any ground water that is contained in these deposits. Hence, the lake deposits are not considered to be a source of either appreciable quantities or good quality groimd water. Sand emd Silt Deposits (Qs) . Recent wind blown accumulations of scuid and silt form a widespread mantle over the alluvial fans, baain deposits, and lake deposits in portions of Surprise Valley, Honey Lake Valley, and Sierra Valley. The deposits axe moderately to highly permeable, but because they are at most only about 20 feet in thickness and are located above the water table, they do not contain any great amounts of water. Sand Dunes (Qsd) . Scattered areas of Recent sand dunes occur along the east side of Surprise Valley, at the south end of Goose Lake, at the east end of Madeline Plains, and on the west store of.EagLe Lake. The dxmes range from 6 to 30 feet in height and are composed of unconsoli- dated beach sand. The dimes are highly permeable, but being sitviated above the water table, contain little water. -67- CH/yPTER IV. GROUND WATER Ground water in amounts needed to provide for existing euad probable future requirements for dojuestic and stock use can be obtained in all ground water basins investigated. Significant potential for economic develojment of ground water in sufficient qviantities for irrigation purposes exists in portions of all the ground water basins evaluated. Preliminary evaluations of the potential for ground water development for each ground water basin and a discussion of the variotis factors involved cure included in this chapter. A brief description of the physical features of each grovind water basin and subbasin is presented. The more important topographic features of each basin axe also described along with conments pertaining to the surface water drainage systems found within each bajsin. A brief geologic history of each individual basin points out the similarities ajid differences in the processes which formed the several valleys. In this chapter, only the principal water-bearing formations found in each ground water basin are discussed. (However, all of the geologic formations found in the northeastern counties are included in the foregoing discussion starting on page 50.) Plates, figures, and tables concerning the ground water geology of each basin are also presented and explained. The influence of geologic struct\ire on the occurrence and movement of ground water is also set forth for each basin investigated. Plates showing generalized lines of equal elevation of water in wells were prepared for conditions as they existed in the Spring of I96O for all but two of the grotind water basins investigated. These plates are found under separate cover but are discussed in this chapter. Plates showing lines of equal elevation of water in wells could not be prepared for Secret axid Humbug Valleys because well data were unavailable for these valleys. -69- The lines of equal elevation for the several baisins reflect either confined or Tmcne areas should yield stiff icient quantities of ground water for most irrigation pTirposes. Yields generally will be somewhat less than in "A" Zone areas. "C" Zone: Fair areas for development of groiond vater. Properly constructed wells located in "C" Zone areas may yield sufficient quantities of ground water for limited irrigation purposes. Yields should be Siifficient for domestic and stock - watering pxirposes, but generally will be substantially less than in "A" or "B" Zone areas. -71- "D" Zone: Poor areas for development of ground water. Properly constructed wells located in »T)" Zone areas may yield sufficient quantities of groxind water for domestic or stock- watering purposes. The possibility of dry holes is much greater in "D" Zone areas than in other areas. Plates showing the areas in each zone for each ground water basin summarize the conclusions as to potential for quantitative development of ground water. Classification of each area is based upon interpretations of the data regarding geology, precipitation, and ground water. k brief summary of the mineral quality of ground water within each groxind water basin is presented. Known hazards due to poor quality water are pointed out in the text and areas of hazard are prominently indicated on the plates showing potential for development of groTind water. Under the subheading "Concluding Remarks and Recommendations" comments appropriate to each specific ground water basin are set forth. This i investigation has attempted to collect, integrate, and evaluate all available i data in order to develop and present a generalized opinion of the ground water* development potential within certain ground water basins located in Northeaste California. It is realized that some of the details of this opinion are of * i preliminary nature and should be revised as additional data are obtained. It is believed that this bulletin and particularly the evaluations presented in this chapter, provide a foundation which will aid in making decisions con- cerning the development of additional groTind water supplies. In the atten^Jt to integrate and evaluate the available data, the need of additional infonnatij became quite apparent. Some of this needed information could be obtained frou new wells, while other information necessitates records to be coUected over long periods of time. Certain information can be obtained only by specialized geologic and hydrologic investigations. Thus, if a more reliable opinion is required concerning the ground water development of these basins, the -72- department's continuing data collection activities should be supplemented by specialized programs to obtain all the data needed. Throughout the text, the use of wells of usual construction for developing gcouai water is frequently referred to. Ihere is another method by vAiich near-surface ground water has been developed for stockwatering and limited irrigation use within certain portions of the area of investi- gation. This method involves the excavation of sumps to intercept the near-surface groimd water. The yield from sumps is usiially lower than the yield of good irrigation wells, but their cost is many times lower. The operation of a sump for irrigation use can be accomplished without inter- fering with its continued use for livestock. There are some locations in most of the basins in the northeastern counties where this method of ground water develojment seems feasible. A high water table within permeable deposits is the major prerequisite for this type of ground water develop- ment. However, it must be realized that incorrect location, a severely fluctuating water table, local overdevelopment of ground water, or a pro- longed drought may severely restrict the potential yield of such an installation. -73- Goose Lake Valley Groiind Water Basin This investigation concerns itself only with the California portion of the Goose Lake Valley grovind water basin, although a considerable portion of the basin lies in southeni Lake County, Oregon. Goose Lake Valley, about 47 miles long by 12 miles wide, extends into Oregon from northern Modoc County. From the Fremont Mountains to the north and the Warner Mountains to the east, several streams flow into the valley and enter Goose Lake. The bed of the lake covers a large portion of the valley, particularly in California. The bed lies at elevation 4,692 feet and was exposed in the early 1930' s when the lake was dry. In the extreme southerly portion of the basin, streams flow into North Fork Pit River rather than into the lake, although in 1869, when the water level of the lake rose to elevation 4,716 feet, the lake itself spilled into the river. Three small towns lie within the California portion of the basin: Davis Creek, Willow Ranch, and New Pine Creek. The Modoc Plateau covers an extensive area west of the valley, and the Devils Garden area of the plateau lies to the southwest. In California, the eastern portion of the Goose Lake Valley ground water basin is subdivided into California portion of the Willow Ranch sub- basin, the Davis Creek subbasin, and the Franklin Creek subbasin. Plates 4 and 5 show these subbasins. The California portion of the Willow Ranch subbasin, about 11 miles long and 2 miles wide, extends south from the California-Oregon border to Willow Ranch. The easterly and southerly boundary of this subbasin is along the contact between the water-bearing materials, such as unconsolidated sedijnents and permeable volcanic rocks, and essentially nonwater-bearing rocks of the Warner Mountains, and those in the vicinity of Sugar Hill. The westerly boundary of this subbasin is considered to be the edge of the bed of Goose Lake because materials underlying the lake bed are relatively impermeable. -75- The Davis Creek subbasin generally comprises valley floor lands within a radius of about 3 miles from the community of Davis Creek. Only a portion of the boiuidary of the subbasin can be defined vrLth available data. The northwesterly and northerly boundary of the subbasin is the edge of the bed of Goose Lake. The easterly boundary of the Davis Creek subbasin is along the contact between the water-bearing materials and essentially nonwater-bearing rocks of the Warner Mountains and the Sugar Hill complex. The southerly boundary is the surface water drainage divide between Roberts Creek and Linnville Creek, The extent of the subbasin to the west is unknowi The Franklin Creek subbasin extends southerly from the Davis Creek subbasin and includes those lands drained by the North Fork Pit River. The easterly boundary is defined by the impermeable rocks of the Warner Mountains and the northerly boundary by the drainage divide between Roberts and Linnvil Creeks. Ground water data are lacking to define the westerly and southerly boundaries, therefore the surface water drainage boundary of Goose Lake ValleJ drainage basin is considered to be the boundary along the southerly and westerly perimeter of the subbasin. Surface exposures of the various geologic formations of the California portion of Goose Lake Valley area are shown on Plate 3, Areal Geology, Goose Lake Valley Ground Water Basin. Plate 4, Generalized Lines of Equal Elevation of Water in Wells in Near-Surface Aquifers, Goose Lake Valley Ground Water Basin, Spring I960, presents a generalized picture of the elevation of unconfined and semi-confined ground water within the California portion of the gix>und water basin. Plate 5, Generalized Lines of Equal Elevation of Water in Wells in Confined Aquifers, Goose Lake Valley Ground Water Basin, Spring I960, indicates the general elevation to which confined ground water would rise in a well. Plate 6, Potential for Development of -76- Ground Water, Goose Lake Valley Ground Water Basin, presents preliminary- evaluations of the potential for grovind water development within the California portion of this basin. Areas of hazard because of poor quality- water are also indicated on Plate 6. Geologic History During the Pliocene epoch, a large fresh water lake covered what is now north central Modoc County. The lake was bounded on the east by a range of hills that were in the process of being tilted to form the Warner Mountains. The lake apparently drained northwesterly toward the ancient Klaunath River system. At some time in the early Pleistocene epoch, vents and fissiires opened up west of the Warner Mountains and huge volumes of lava poured out. These lavas blocked the drainage to the Klamath River and the lake became isolated. Subsequently, drainage began to develop to the southwest as erosion of the canyon of North Fork Pit River began. As the canyon was deepened, the headwaters of the river moved northward. Finally, a new outlet to Goose Lake Valley was formed, and the lake drained southward into the Pit River system. After the close of the Pleistocene epoch, the climate became drier and the lake began to dry up. Today, Goose Lake is an intermittent lake, and It has been completely dry several times in the last 60 years. Water-Bearing Formations Table 9 briefly describes the geologic formations in Goose Lake Valley. Of these, the principal water-bearing formations in the California portion of the valley are Pliocene to Pleistocene lava flows, near-shore deposits, and Recent valley sediments. -77- GEOLOGIC FORMATIONS IN GOOSE LAKE VALLEY GEOLOGIC AGE STRATIGRAPHY APPROXIMATE THICKNESS IN FEET PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS SAND DUNES Qad i Unconaolldftted tin* s«nd« wind deposited. Cont&lna little water* <^ i thiconsolldated olay aid allty clay, alkali present. ^: t7nconsolidated» interatratl fled olajt 8llt» md sand. May have alkali. Peraeablllty aioderate to slight* Yields small supplies of water to shallow wells. QjSl ! tJnconsolidated, poorly sorted silt and sand with Isnaes of grsTel. Moderate permeability. Yields moderate quantities of water to wells. eraieabla. Hearly lq>ermeable* May yield sittll amounts of water from fractures. Hearly iiiq}erBMable. May yield small amounts of water from fractures and Joints* 78 Pliocene to Pleistocene Lava Flows * The Pliocene to Pleistocene lava flows are generally highly permeable and where exposed at the ground surface are excellent areas for ground water recharge. Only a few producing water wells have been drilled into the basalts; consequently, only limited data on the water yielding capabilities of the basalt are available. Lava flows on the west side of Goose Lake appear to contain numerous permeable zones which may be capable of providing large quantities of grovind water to irrigation wells. In addition, well log data indicate the presence of several basalt flows buried within the valley sediments in the Davis Creek subbasin. These layers of fractured lava are interbedded with sand and clay and yield moderate to high quantities of ground water to wells, Near-Shore Deposits . Extensive near-shore deposits occur along the east side of Goose Lake Valley. The near-shore deposits appear to be moderately to highly permeable, especially in a horizontal direction. Occasional cemented zones and beds of silt and clay tend to confine ground water, and the more permeable beds of sand and gravel yield artesian water to wells. The near-shore deposits may yield large quantities of ground water to wells. Recent Valley Sediments . Recent valley sediments include alluvial fans, intermediate alluvium, and basin deposits. The lake deposits in Goose Lake Valley are also included with the Recent valley sediments. As lake deposits yield only small amounts of ground water to wells they will not be discussed below. Alluvial fans are generally the most permeable of the valley sediments. The east side alluvial fans, about 300 feet thick, are considered to b^ the most important sources of ground water. The upper portions of the -79- fans are moderately to highly p>enneable and if sufficiently recharged can yield large quantities of ground water to wells. The middle and lower portions of the fans, although less permeable, contain confined aquifers iiidiich may yield moderate amounts of ground water to wells. In contrast, alluvial fans along the west side of the valley are only about 100 feet thick and are of relatively low permeabilityj hence, they can yield water sufficient only for domestic and stock purposes. Intemediate alluvium occurs at the lower limits of many alluvial fans. It is generally about 100 feet thick and is underlain in some areas by less permeable lake deposits and in other areas by more permeable alluvial fans and near-shore deposits. The intermediate alluvium is moderately permeable and if sufficiently recharged and of sufficient thickness is capable of yielding moderate quantities of water to shallow domestic and stock wells. Basin deposits occur on the flat, poorly drained portions of the valley. They may be up to 100 feet thick and are underlain by relatively impermeable lake deposits, or in a few localities, by more permeable alluvial fan or neaz>-shore aeposits. Numerous areas of basin deposits are crusted with alkali. Because of their low to moderate permeability, the basin deposits yield only small quantities of ground water to wells. Influence of Geologic Structure on Grotind Water Goose Lake Valley is a downfaulted block bounded by many scarps. Generalized geologic structure of the valley is presented on Figures 9 and 10, >diich are geologic sections showing the probable structural conditio) to a depth of about 1,500 feet below the lake. ■80- ^1 l|D»d OftuOpuOi ^(_ 1IIH JObns S6£ AVMHOIH Sn avOa 3015 1S3M &3AW lid MHO J HiyON ySMd lid MdOJ HldON < I I L wnivo sosn j.33d ni NoavAana 81 GOOSE LAKE VALLEY PI«Utoc«n« Baiolt GOOSE LAK£ Botm D^poLtt^ ^X — ^^ ^^^^,^ :; — -_ -_ _R consist of perme- able basalt flows of Pliocene to Pleistocene age. Precipitation and surface runoff infiltrates the permeable materials and then percolates valleyward to recharge the valley sediments. The portion of the surface drainage area boundary on the west side of Goose Lake Valley shown on Plate h approximates the extent of the recharge area on the west side of Goose Lake Valley ground water basin. Mean seasonal precipitation along the shore of the California portion of Goose Lake is approximately 12 to ik inches. Mean seasonal precipitation ranges to about l8 inches along the foothills of the Warner Mountains and to about l6 inches at the southern edge of the valley floor. The precipitation station within Goose Lake Valley possessing the longest record is Lakeview, Oregon, where the estimated mean seasonal precipitation is 13.30 inches. The recorded maximum and minimum precipitation at this station is 22.82 inches dioring the I906-O7 season, and 6.9I inches during the 1930-31 season, respectively. This degree of variation of precipitation is probably typical for Goose Lake Valley. Most of the groiind water recharge to deeper aquifers along the east side of the California portion of Goose Lake Valley is derived from infiltration of surface water, generally along the foothill portions of stream channels. The streamflow here is generated by precipitation on the -83- Warner Mountains, mostly occurring in the form of snow during the winter months. The meaji seasonal precipitation on these mountains is approximately 18 inches along the foothills and reaches estimated maximums of 32 inches near Mount Vida and 34 inches along the crest approximately 3 miles east of Scamraon Reservoir. A relatively large portion of precipitation occurring along the west side of the valley infiltrates upland recharge areas. On the Devils Garden, mean seasonal precipitation is about 12 to 14 inches. Even though these precipitation values are relatively low, a generally thin soil mantle and limited amounts of natural vegetation in the Devils Garden area allows a considerable portion of this precipitation to recharge xinder- lying ground water bodies. North of the Devils Garden, where soils are deeper and vegetation is of greater density, precipitation is also greater. Within this portion of the west side recharge area, mean seasonal precipita- tion ranges fi\)m 14 inches near Poindexter Reservoir to upwards of 24 inches along mountain peaks near the boundary between California and Oregon. On the west side of the valley between McGinty Point and the State boundary, ground vater Intercepted by wells is moving from the Modoc Plateau eastward toward Goose Lake. No information is presently available to determine the direction of movement south of McGinty Point, although the most probable direction of movement within the first 300 feet of depth is toward Goose Lake in Township 45 North, Range 13 East, M.D.B.^., and toward North Fork Pit River and its tributary streams in Township 44 North, Range 13 East, M.D.B.SM. Generalized lines of equal elevation of water in wells are shown on Plates 4 and 5. The general direction of ground water movement indicated for most ground water within the California portion of the east side of Goos«< Lake Valley is from the foothills of the Warner Mountains toward Goose Lake, -81^- ^ile the remaining portion moYes tovrard North Fork Pit River and its tributary streams. Ground water movement within each of the three sub- basins of the valley is discussed below. Willow Ranch Subbasin . There are two ground water bodies within Willow Ranch subbasin. The upper, essentially unconfined body, is inter- cepted by wells of depths usually less than 50 feet. Recharge to this ground water body is from streams draining the Warner Mountains. Water from these streams infiltrates the highly permeable upper portions of alluvial fans and then moves westward toward Gk>ose Lake. Return water from irrigation within this subbasin is evidently also a source of recharge to this upper ground water body. The lower ground water body is confined and probably occurs in near-shoi^ and related deposits. The piezometric surface of this body has a pattern similar to that of the overlying, essentially vmconfined, gro\ind water body. The piezometric surface of the lower body ranges from 30 feet below the ground water table of the upper body along portions of the foothills, to perhaps 20 feet above the water table at some places at the edge of the lake bed. This lower confined ground water body is re- charged from deep percolation of ground water in the upper portions of alluvial fans. The area depicted in blue on Plate 5 is vriiere the piezo- metric surface of this lower ground water body is above the ground surface. Davis Creek Subbasin . Plates 4 and 5 indicate the probable loca- tion of the ground water divide between the Davis Creek and Franklin Creek subbasins in the Spring of I96O. As a ground water divide is subject to change in location, the surface water drainage divide located north of the ground water divide is considered as the boxindary between the two subbasins. -85- The analysis of the elevation of the ground water surface deter- mined at certain wells within Davis Creek subbasin indicates the existence of at least three sep>arate grotind water movement patterns. Each pattern is assumed to represent a separate grotind water body. Wells of depths generally less than 50 feet intercept ground water moving within near-surface materials in a predominately westerly to northwesterly direction towarti Cioow Lake. The recharge to this ground water body is from alluvial fans along foothill slopes of the Warner Moxintains and from channels of valley floor streams. The ground water mound in the vicinity of Lakeshore Ranch shows that overlying irrigated lands also recharge this ground water body. Local areas of aquifer confinement, one of which is located in Section 19, Town- ship 45 North, Range 14 East, M.D.B.&M., exist within this essentially unconfined ground water body. The observed confinement apparently results from cementation of the upper portions of gravel bed aquifers within certain areas of the near-shore deposits. Wells of depths between 100 and 400 feet apparently intercept ground water moving within near-shore deposits and interbedded Pleistocene basalts. Ground water in this body is recharged by deep percolation in the upper portions of alluvial fans of Davis Cz>eek and Roberts Creek and moves in a northwesterly direction toward Goose Lake. Certain wells of depths in excess of 400 feet located in or close to Section 18, Tovmship 45 North, Range 14 East, M.D.B.&M., apparently inter-i cept a third major ground water body which is confined in sediments and PliO' Pleistocene basalts underlying the Pleistoc«ie basalts. There is some evidence that shallower wells 2 to 3 miles north of the community of Davis Creek also intercept this grovmd water body. Evidence from a few wells which have intercepted this ground water body Indicate that the direction of movement is southwesterly from its apparent recharge area within the -86- Plio-Pleistocene basalt east and northeast of the community of Davis Creek. This apparent direction of movement of the defined portion of this ground water body is therefore perpendicular to the direction of movement of the two overlying gixjvmd vra.ter bodies, Franklin Creek Subbasin . Geologic evidence indicates that several ground water bodies may exist within the Franklin Creek subbasin, particularly in the area near Devils Garden. Wells within this subbasin confirm the exist- ence of at least two ground water bodies. However, as ground water elevation information is available principally from shallow wells, only generalized lines of equal elevation of water in wells in near-surface aquifers can be determined at this time. The general direction of movement of this ground water body is from recharge areas within alluvial fans along the foothills of the Warner Mountains, westerly to southwesterly toward North Fork Pit River and certain tributary streams. Overlying irrigated lands within this subbasin undoubtedly contribute to the recharge of this ground water body. There is some evidence that a portion of this ground water body is inter- cepted by an \innamed slough parallel to the Southern Pacific Railroad, vriiile a remaining portion of this ground water body continues to move westerly, probably to be intercepted by the "outlet channel" of Goose Lake. Present information indicates that the near-surface ground water body is essentially unconfined east of the slough which parallels the Southern Pacific Railroad. No evidence is available pertaining to confine- ment conditions west of this slough. The faulted basalt in Sections 13 and 24, Township 44 North, Range 13 East, appears to act as a restriction to the southerly movement of this ground water body toward North Fork Pit River. This restriction apparently accounts for numerous springs on Crowder Ranch located about 6 miles southerly of the coitenunity of Davis Creek. -87- Present Use of Ground Water Approximately 115 square miles of the 190 square miles of valley- floor lands within the California portion of Goose Lake Valley are occupied by the bed of Goose Lake. Of the remaining 75 square miles, or 48,000 acres, 37,000 acres are considered suitable for the production of irrigated crops. Approximately 9,000 acres of these lands are presently irrigated, primarily by waters diverted from ijnregulated streams. The majority of the 119 wells located during 1957 were utilized primarily for domestic and stock watering purposes. Only 9 wells were irrigation wells. These wells, the yields of which range from 525 to more than 2,000 gallons per minute, provide total or supplemental irrigation water to approximately 1,000 acres of cultivated lands. Based on the apparent availability of ground water storage and rechargaMlity of the permeable materials of the basin, present pumpage of groiond water apparently extracts only a very minor portion of the total amount of ground water avail- able for development. Ground Water Development Potential Within the valley floor area of Goose Lake Valley all four zones of potential for development of ground water are present. The area of the valley floor in each classification is shown on Plate 6, The general condi- tions idiich presently govern the potential for development of ground water within each zone found in this basin are discussed below. "A" Zone . The "A" Zone areas are underlain by permeable materials that receive adequate recharge. The areas are situated on the middle and upper portions of the alluvial fans of certain creeks draining the Warner Mountains. The extent of the area of the "A" Zone of the Davis Creek fan is -88- modified hy several buried lava flows. These buried lava flows and their associated sediments apparently contain large quantities of confined ground water. "B" Zone . Much of the irrigable land in Gk)Ose Lake Valley is located within "B" Zone areas. On the east side of the valley, most of the "B" Zone areas are underlain by alluvial fan materials. These materials are similar to those underlying adjacent "A" Zone ai>eas, although in general they are somewhat thinner and less permeable. The recharge potential for the "B" 2k>ne areas on the east side is generally someiidiat less than for the "A" Zone areas. The Davis Creek "B" Zone area is probably underlain to some extent by the same buried, permeable basalt flows vrtiich underlie the Davis Creek "A" Zone area. The presence of less permeable near-shore deposits in this "B" Zone probably reduces the overall permeability and hence reduces the potential yield of groiind water to wells. The intermediate alluvium along lower por- tions of Willow and Lassen Creeks are underlain by less permeable near-shore deposits. The intermediate alluvium appears to be fairly permeable and could provide satisfactory yields of ground water to wells. Along the west side of Goose Lake, the "B** Zone areas are composed of intermediate alluvium and terraces underlain by basalt flows containing highly permeable layers of fragmented volcanic rock. Wells here could produce large quantities of ground water provided a sufficient nvunber of these layers are intercepted. Recharge to these layers appear to be in sufficient quantity to supply ground water for irrigation requirements within the "B" Zone areas along the west side of Goose Lake Valley. -89- I "C Zone * The "C" Zone areas are situated in four general loca- tions. One area extends from New Pine Creek south to Sugar Hill and is underlain entirely by intermediate alluviTun, basin deposits, and near-shore deposits. The second "C" Zone area is west and northwest of the community of Davis Creek. This zone contains intermediate alluvium, basin deposits, and near-shore deposits near the surface, triiile below a depth of about 50 jft feet, less permeable lake and near-shore deposits are found. VHiere lake '^' deposits underlie the surface materials, there is the possibility that ground water could be obtained only from the surficial deposits. The third "C" Zone area is situated north and southeast of Davis Creek and is composed entirely of intermediate alluvium, alluvial fan, and near-shore deposits. Because these three areas have no appreciable surface recharge, extracted ground water could only be replenished by lateral movement from areas of recharge located along flowing streams. The ground water develop- ment potential of these three "C" Zone areas is thus reduced. The fourth "C" Zone area is west and south of Goose Lake. Although similar to adjacent "B" Zone areas, it also probably has less surface recharge and consequently is considered to have a lower overall developnent potential. "D" Zone . The areas classified as "D" Zone have the lowest ground water development potential aund are of two basic types. One type is located adjacoit to Groose Lake and is composed of basin deposits underlain at depths of less than 50 feet by relatively impermeable lake deposits. Any water in wells located here would be derived mainly from shallow materials, in many places by slow seepage from the lake itself. The other type Is located in areas adjacent to outcrops of impermeable rock. Surface materials in these areas may be permeable, but because they are underlain at shallow depths by impermeable rock, wells in these locations would yield little, if any, ground water. -90- General . With the present level of agriciiltural development, the irrigation water supply derived from direct diversion of surface water is usvially siifficlent for most lands until about the middle of June \dien there is usually a need for sxqjplemental irrigation water. As agricultvcral development increases the need for supplemental water will increase correspondingly. Ground water in many instances can be utilized to meet the Increased need. Within Willow Ranch subbasln, irrigable lands underlain by alluvial fans appear suitable for an increased level of ground water development. At some increased level of development it appears that natural recharge will be insufficient for the required pumpage. In this event, the construction of ground water recharge facilities may forestall overdraft conditions. Increased ground water development probably will aggravate the present ^xa- desirable water quality condition within partlc\ilar portions of this sub- bsisin. It may be possible to control this problem to some extent by develop- ment of selected aquifers containing good q\iality ground water. Proper sealing of wells which act as conduits between aquifers containing the pooler qtxality waters and aquifers containing the better quality waters should aid in maintaining the quality of ground water. Within a portion of this sub- basin, the plezcanetric stirface is above the ground stirface. The flowing wells within this area are particularly useful for stockwaterlng. Caution shoiild be exercised In construction of such wells within particvilar areas as it appears possible that the groxmd water developed may be of poor quality. Within the Davis Creek and Franklin Creek stibbasins the level of ground water development which may be achieved before natural recharge facilities become a limiting factor, appears to be higher than within the Willow Ranch subbasin. It appears possible that the Alturas formation .90.- underlies most of Franklin Creek subbasin and may extend imder a considerable i portion of Davis Creek subbasin. If so, wells in the order of 800 feet deep may intercept ground vater within this formation which apparently is adequate! recharged. Also, buried basalt flows may be intercepted at depth. Ground Water Storage Capacity The ground water storage capacity to a depth of 500 feet has been estimated to be approximately 1,000,000 acre-feet. How much of this quantity; is usable, or how much usable storage exists below 500 feet is not presently known. It is reasonable to assume that a significant amount of ground water could be developed. Quality of Ground Water , Ground water in Goose Lake Valley ground water basin is genersilly of excellent mineral quality, being usually calcium bicarbonate in character and suitable for most beneficial \ises. There is an area of approximately 3 square miles located east of Goose Lake and south of New Pine Creek whei« wells deeper than 200 feet have encountered sodium bicarbonate waters. These' waters contain excessive concentrations of fluoride and boron and are generall considered unsuitable for irrigation or domestic uses. The waters are thermal and are foimd associated with and in close proximity to several fault zones which traverse the area. Water Qxiality Problems The most significant body of poor quality water presently existing in Goose Lake Valley ground water basin is the thennal water shown on Plate 6. However, Goose Lake, which overlies a large portion of the ground water basin, is also poor in quality, because it contains high concentrations of total dissolved solids, sodiiom, and boron. -92- Under present develojment and existing hydrologic conditions, these poor qiiality waters do not pose a signif iccmt threat to adjacent good quality waters. Increasing ground water extractions could depress ground water levels near the lake, and new ground water gradients could easily be established that wovild lead to the migration of poor quality waters and subsequent impairraent of adjeu:ent good quality waters. In the eurea underlain by thermal mineralized water, any improperly constructed or vtnused wells over 200 feet deep could create a direct inter- connection with the deep mineralized waters and shallow good quality waters, and result in the impairment of the good quality waters. Conclusion Additional ground water may be developed within Goose Lake basin. This is particularly true for areas underlain by alluvial fans along the east side of the California portion of the valley floor. Within the northern portion of this side of the valley floor, there ajjpears to be a ground water quality problem area. Caution should be exercised in develop- ment of ground water within this area. If the Alturas formation and buried basalt flows underlie the southern portion of the valley floor, and if these materials axe recharged from the Devils Garden ai^a, ground water developnent i>otential of the southern portion of the -valley floor is considerably enhanced. It is concluded that the basic data collection activities of the Department of Water Resoxirces should be continued in order to facilitate future qxoantitative ajid qualitative analysis of the ground water basin. Encouragement should be offered to local agencies in their efforts to develop the ground water potential in the manner best suited to local problems and in accordance with information in this bulletin. -93- Alturas Ground Water Basin Altiiras ground water basin is located in central Modoc County and i Includes areas adjacent to Pit River and its tributaries near the City of Alturas. 1!he valley floor elevation is about 4,300 feet. South Fork Pit River heads in Jess Valley in the south Warner Mountains and flows in a westerly direction through the sniall town of Likely. From Likely the river I turns north and flows through South Fork Pit River Valley to Altvuras idiere it joins North Fork Pit River, North Fork Pit River flows in a southerly direction from near Goose Lake to its confluence with South Fork Pit River at Alturas. From this confluence. Pit River flows in a westerly direction through Warm Springs Valley. Alturas ground water basin is bounded by the Warner Mountains on the e&at, Devils Garden on the north, and roOLLlng hills * to the south and west. Alturas ground water basin is composed of South Fork Pit River Valley subbasin and Warm Springs Valley subbasln. As shown on Plate 8, South Fork Pit River Valley subbasin consists of lands adjacent to both North Fork Pit River and South Fork Pit River. It also includes soane lands located westerly of the confluence of the two forks of the Pit River, The r em ai ni ng area of Altviras ground water basin is designated as Weirm Springs Valley subbasin. Sxirface expostires of the various geologic fonnatlons of the Alttiras area are shown on Plate 7, Areal Gedogy, Alturas Ground Water Basin. , Plate 8, Generalized Lines of Equal Elevation of Water in Wells in Aquifers, ^i Alturas Ground Water Basin, Spring I96O, is a generalized picture of the elevation of the ground water within the ground water basin. Plate 9, Potential for Develoiinent of Ground Water, Altiiras Ground Water Basin, -95- presents the parellnlnary evaluations of the potential for ground water develoxnent vlthln this basin. Areas of hazard because of x>oor quality vater are also indicated on Plate 9. Geologic History Duriiog the late Miocene epoch, when the Warner Mountains vere being tilted upward, the Alturas basin vas the site of a broad valley occuplec by a very large lake. The valley received sediments from the mountains, vhich sediments novr compose a portion of the lower member of the Alturas fonnation. During the Pliocene and early Pleistocene epochs, Tule Mountain, an ancient volcano, produced many lava flows which poured out into the valley, During the same time interval, violent explosions shook the land, and huge vdiames of billowing ash and sulfurous gas filled the air. QSiere were also associated eruptions of clouds of volcanic solids and gasses which raced downhill at high speeds. After blanketing much. of the valley, the volcanic clouds solidified to form the Warm Springs txiff . Again a period of quiescence ensued, and a lake reoccupied the valley. Sediments from this second lake make up the upper member of the Alturas formation. Wide- spread fissxire eruptions of lava during the Pleistocene epoch created Devils Garden. Contemporaneous and subsequent favilting, folding, and erosion formed the Alturas basin. Near the close of the Pleistocene epoch, there were lakes occupying South Fork Pit River Valley and Warm Springs Valley. The two lakes were connected by a strait along JE^e Grass Swale. Eventually, erosion formed the present course of Pit River, and the two lakes were drained leaving the valleys much as they are today. Water-Bearing Formations Table 10 briefly describes the geologic formations in Alturas basin. Of these, the principal water-bearing formations are Plio- Pleistocene and GEOLOGIC FORMATIONS IN ALTURAS BASIN GEOLOGIC AGE PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS Highly porraeable, but usually above sone of saturation. Yields water to springs. ^ap z Unconsolidated deposits of organic louck and fibrous peat. Found only in Jess Valley. Very low permeability. Uninpo tant as source of ground water. Qb: Unconsolidated, inter strat- ified clay, silt, end fine sand. Pemeability moderate to slight. May yield small supplies of water to wells. Qftl ! TMconsolidatedf poorly sorted silt and sand with some lenses of gravel. Moderately permeable. Yields moderate quantities of water to shallow wells. ftf ; Unconsolidated to poorly consolidated^ rudely strati- fied sand, silt, and gravel, with lenses of clay. High permeability. May yield large quantities of water to wells; may contain confined water. ftls ! Semiconsolidated mixture of blocks of basalt in matrix of clay and sand. Of low permeability and of littl< importance to groxmd water. (^pyb Hi^ly Jointed, flat- ylng olivine basalt flows with interbedded scoriaceou zones. Unit as a whole moderately per- meable. Acta as forebay for recharge to adjacent sediments Qpvp; ^Ta Moderately permeable but con- tains little water due to being above saturated cone. Qps i Slightly consolidated and cemented, poorly to well stratified pebble and cobble gravel with lenses of sand and silt. Of moderate permeability. May yield fair to moderate quan- tities of water to wells. TQa : Lake deposited tuff, ashy seuidstone, gravel, and diato- ral te . Indi at ingu ishabl e from lower meatber. Moderate to high permeability. Yields large quantities of water to wells. Contains con- fined water. Tftvb ; "HTo Unit as a ^ole is moderately permeable. Yields water to numerous springs. Acta as forebay for recharge to adja- cent a«diments« May yield moderate amounts of wiater to wells. Tgvt! Massive pumice lapilli tuff. Jointed beds of welded tuff, minor beds of ashy sandstone. Transmits small quantities of water along Joints and frac- tures. Sandstone beds may yield moderate quantities of water. Tfta t Indistinguishable from upper member. Hay be Mlooej in part. Same as upper neadaer. •■ ^ • j r . : . ' .* ' ^-^-^ plat Tpvb ! of ' Tmvp ! Bedded mudflows, tuffs, ashy sandstone, and diatomite. May be correlative to Turner Creek formation. Upper por- tion may grade Into lower member of Altttras formation. Tmto : Massive mudflows and tuffs with beds of ashy sand- stone and diatoinlte. Upper portion may be correlative to lower member of Alturas formation. Essentially in^ermeable. Pair to poor overall permea- bility. Locally yields small amounts of water to springs. Essentially io^iermeable. Tranamits only minor quantities of water along Joints, Of low overall permeability. A few permeable beds may yield limited quemtlties of ground water to wells. Of low overall permeability. A few permeable beds may yield limited quantities of ground water to wells. Nearly linpermeable. May yield small amounts of water from fractures and Joints. Pleistocene lava flows^ the Alturas fomatlon, near-shore deposits, and Recent valley sediments. Fllo- Pleistocene and Fleistocene Lava FLovs . Pllo-Plelstocene and Pleistocene lava flows found In Alturas basin are generally moderately permeable and consequently Tdaere exposed comprise a ground water recharge area. There are no }mown water wells drilled In areas of siirface exposures of these lava flows. Therefore, no direct data on the water yielding capa- bilities of the basalt are available. The numeroxis springs in beisalt areas, | however, attest to the water yielding potential of certain zones. Several wells south of Alttiras Intercept buried lava flows. Although it is not possible to ascertain the exact quantity of ground water obtained from each lava flow, it is probable that the lava flows yield moz« ground water than I the surrounding materials of the Alturas formation. Alturas Formation . The Altiuras formation is widespread both at the surface and at depth in Alturas ground water basin. The formation consist of moderately consolidated, flat-lying beds of tuff, ashy sandstone, and diatomlte. All of the materials were deposited in lakes which occupied this eurea at various times from the latter part of the Miocene epoch to the Fleistocene epoch. The sedimentary portion of the Altiiras formation consists of two nearly identical members separated by a HLlo-Flelstocene basalt member and the Warm Springs tuff member. The two sedimentary mesibers aoce not differentiated on Plate 7 because of the marked similarity of the sedimentary beds making up the upper and lower mesibers. The sediments of the Alturas formation axe the principol water yielding materials in Altxiras ground water basin. The sediments have a moderate to high overall pezmeablllty, emd 'vdiere satiirated, may yield ground -9a- vater in quantities sttfficient for irrigation purposes. They contain both unconfined and confined ground vater. Hear- Shore Deposits . Extensive near- shore deposits occur on the east side of North Fork Pit River Valley, Minor areas of these deposits also occur at other localities vithin Alturas ground vater basin. lEbere is only one veil in Alturas basin known to draw its entire supply from the near- shore deposits. Based on this veil, it appears that the near- shore deposits are moderately permeable and, where sattirated, me^ yield fair to moderate supplies of unconfined and semiconfined ground water to veils. Recent Va.i1ey Sediments . This group includes alluvial fans, intermediate alluvium, and basin deposits. All of the Recent valley sediments are fairly thin, being at most 50 feet in thickness. Of the three, the alluvial fans are usually the most permeable as they are frequently composed of highly penneable mixtures of silt, sand, and gravel. Where they are vithin the zone of saturation, the fans vill usually provide high yields of confined and semiconfined vater to veils. The intermediate alluvixm is of somevhat lover permeability as it contains a greater amount of silt and clay. Intermediate alluvl\im, however, can provide moderate quantities of ground vater to veils. The basin deposits are the least permeable of the Recent valley sediments. These deposits contain large percentages of silt and clay and thus yield only small quantities of vater to veils. Influence of Geologic Structure on Ground Water The geologic structure of the Alturas area is one of gentle anti- clines and syndines broken by numerous faults. An indication of this structure is shown in Figures 11 and 12, vhich are generalized geologic sections shoving the probable structural conditions to depths of about 1,000 feet. -99- 'r •ting iifOMKutou 02 ON poon Xiunoo )I09JO •lOMS J**oio 662 ^omtiiiH Sn 6£l ^OMi/OfH •lOiS 95 'ON pooy XfuiKj !6C 'oMi/a/H sn rL 3/ CN foot! Xtimco mmr WW Ummm my ^h i/JAfi^ ltd 1 V A 3 n 3 100 jioAj»s0tf /n0)i ■yyas •ling viioustuiou 0/ ON pooy Atunoo USA/a lid PS 'ON Pooa Xfunoo •fipiy MtnbniJOd jiOAjasay tiiyjin I Ii c lt§I' t'l l°-t ,L S££ /omi/eiH sn 09 ON POOH 'luKOO o 29 ON pooa Xiunoo .L WfliWQ SSSn i33J Nl NOIiVABia 101 The Alturas formation has been folded into three gentle faulted syncllnes. The eocis of one passes in a northwesterly direction through the City of Alturas; the second is roughly parallel to the first and passes Jtist east of Rattlesnake Butte; the third is also generally parallel and passes Jvist vest of the town of Canby. The three syndines are separated by gentle anticlines. Synclines are important to ground water in that water confined within a given bed will generally be under a greater head along the axis of the syncline than along its limbs. Anticlines are importsuat to ground water in that they may position certain water-bearing beds closer to the ground surface. Many of the faults shown on Plate 7 inaiy have distinct effects upon ground water. The faults cutting through the Pliocene to Pleistocene lava flows frequently contain permeable zones which enable precipitation to infiltrate and then percolate laterally and downward. This accounts for the springs located along many fault zones. If the permeable zones along a fault extend deep enough into the earth, ground water can circulate to great depths and return to the surface as heated, mineralized water such as is fovuid at Kelly Hot Springs. In contrast, faults cutting through sedimentary materials may position an aquifer opposite an aquidude and thus restrict or impede the movement of ground water. This is the case wherever permeable beds of the Alturas formation have been moved opposite Impermeable beds. A barrier to ground water movement may also exist where a govige- filled fault zone cuts across permeable beds. Recharge and Movement of Ground Water Upland recharge areas, shown on Plate 8, consist of permeable lava flows of ELlo-Pleistocene and Pleistocene age. Precipitation falling -102- upon these areas infiltrates the lava flows, and moves toward the valley floor area. The mean seasonal precipitation on the valley floor areeus within Altiiras basin is approximately 12 inches in Warm Springs Valley, ranges from approximately 6 to 12 inches in South Fork Pit River Valley, and averages about 12 inches in North Fork Pit River Valley. The mean seasonal precipitation on the upland recharge areas to the north and southwest of the valley floor areas ranges from 12 to upwards of l6 inches. On the upland recharge surea to the east of the floor of North Fork and South Fork Pit River Valleys, the mean seasonal precipitation ranges from 8 to l6 inches. The recorded maximum and minimum seeisonal precipitation at the Alturas Ranger Station, located near the southern edge of the City of Alturas, was 21.09 inches during the 195I-52 season and 6.kk inches during the I93O-31 season. I9ae mean seasonal precipitation for the Altiiras Ranger Station is 12.16 inches per year. Variations from mean seasonal precipitation similar to those at the Altureus Ranger Station a,re to be expected over the valley floor and upland recharge eurecis of the Alturas giwrnd water basin. The direction of movement of ground water generally follows the topography in most places, aa indicated by the generalized lines of equal elevation of water in wells shown on Plate 8. The various faiits which cross the basin \mdoubtedly modify this general movement pattern. Alturas ground water basin is divided into two subbasins: South Fork Pit River subbasin, and Warm Springs Valley subbasin. This division is based on the presence of a material of low permeability running the length of the mesa land which separates South Fork Pit River Valley subbasin from Warm Springs Valley subbeisin. Ground water movement within each of these subbasins is discussed below. -103- SOTTbh Fork Pit River Valley Suibbasln . Along the northwesterly side of North Fork Pit River Valley, ground vater apparently moves through the Altiiras formation and Warm Springs t\jff toward the valley floor area. Along the southeasterly side of this valley, the probable direction of movement of some of the ground -water is westerly toward North Fork Pit River The remainder moves southwesterly toward Parker Creek where it is partially Intercepted. The basalt and Warm Springs tvtff near Highway 395 bridge across North Fork Pit River, Section 33, Township k3 North, Range 13 East, M.D.B.&M., acts aa a partial restriction to the southwesterly movement of the near-s\rrface ground water. This restriction, plus some effect from a diversion dam at this location, results in a high water table condition throughout the lower portions of North Fork Pit River Valley. | Ground water appears to move westerly into the lower Pine Creek area from the extensive upland recharge area of ELio-ELelstocehe basalt in the upper Pine Cr«ek and Plum Creek drainage areas. Most of the water recharged from the Fitzhugh Creek area probably moves westerly toward that portion of South Fork Pit River Valley near Signal Butte. Ground water in the ELio-Pleistocene basalt and alluvial fan deposits along the r emain der of the east side of South Fork Pit River Valley apparently moves westerly toward the valley floor. Along the west side of the valley, precipitation Infiltrates the basalt, then moves generally easterly toward the valley floor through the \inderlying Alturas format ion. Within the valley floor area of South Fork Pit River Valley, water moves in a northerly direction toward Altxiras. South of Signal Butte there is considerable ground water recharge from irrigation water and from the East Side and West Side canals. There appears to be a peurtial restric- tion to the northerly movement of the near- surface ground water near an -10^^- expoBvre of Warm Springs tuff northwest of Signal Butte. !I!he effect of this partial restriction Is to maintain a very flat ground water gradient and a generally high water table condition throughout the portion of the valley south of Signal Butte. Noirth of the City of Alttiras, the Altureis formation Is recharged from the lavas of DevUs Garden. The direction of ground water movement within this ground water body Is southwesterly to westerly. Several municipal wells of the City of Alturas Intercept this ground water hody. An overlying near- sxirf ace ground water body In this same area Is recharged by Infiltra- tion of surface runoff frcoi adjacent areas of impermeable tuff. A ground water depression occurs In this area because recharge Is Insufficient to meet the extractions from this upper ground water body. For lands located west of the confliience of the tvo torka of Pit Elver and vlthln the respective drainage areas of Pit River and Battle- snake Creek^ the near- surf £ice ground water moves toward and Is Intercepted by these streams. All near- siirf ace ground water In the vicinity of Alttiras tends to move toward the confluence of the two forks of Pit River. Most of the ground water subsequently rises to the surface and flows out of the subbasln by way of Pit River. Eicposures of Warm Springs tuff in Sections 10 and l^f Township k2 North, Range 11 East, M.D.B.SeH. , act as a partial barrier to the westward movement of ground water from South Fork Pit River Valley STibbasin to Warm Springs Valley subbasln. i Wann Springs Valley Subbcusin . The general direction of movranent of near- surface ground water along the northern side of Warm Springs Valley subbasln is from the recharge areas in the Devils Garden southerly toward Pit River. Blacks Canyon and the lower portion of Clover Swale locally modify this generally southerly diz>ectlon of movement. Along the south side of Warm Springs Valley, the general direction of movement is northerly -105- from the recharge areas of Pllo- Pleistocene basalt toward Pit River. AgedJi, as along the northern side of the valley, topographic depressions locally alter this movement pattern. Ground vater vlthin the Hot Creek drainage area is sex>arated from the near- surface ground vater in the remainder of Warm springs Valley by a barrier of Warm Springs tuff. Ground vater In the Hot Creek drcLlnage area apparently moves southerly toward Fit RLver. Along the east side of Warm Springs Valley, a generally vesterly movement of near-surface grovind vater prevails. Two peurtial restrictions to the movement of near-surface ground water occur in Warm Springs Valley. One is Rattlesnake Butte which deflectsf the southerly movement of ground vater. The other is the outcrop area of Warm Springs tuff in Sections 32 and 33, Township k2 North, Range 10 East, M.D.B.&sM. This tuff restricts the vesterly movement of near-s\arface ground vater and accounts for the flat vater table found to the east. It probably has little effect on underlying, deeper aquifers. No analysis of ground vater movement can be made of the deeper, confined agciifers in Warm Springs Valley subbasin, as these aquifers are essentially undeveloped. The ground vater in these eujuifers probably moves very slowly. Present Use of Ground Water For the present level of develonnent, 33,000 acres of the 76,500 acres of valley floor lands in the Altxiras gro\md vater basin are irrigated by surface vater supplies. The available irrigation supplies from surface vater development have, in part, eliminated the need for extensive develop- ment of available ground vater supplies for Irrigation purposes. Of the 286 wells located vlthin the basin, only lU are irrigation veils, 5 are municipal veils of the City of Alturas, and the majority of the remainder -106- are xised for domestic and stock- vaterlng purposes. The reported yields f ran the Irrigation veils range from about 300 gallons per mlniite to in excess of 1,000 gallons per minute. The municipol wells yield from 200 to 1,000 gallons per minute, averaging ELTOund ^400 gallons per minute. Wells for domestic and stock purposes usually have lower yields. Ground Water DevelopBient Potential Within the Alturas ground water basin all four zones of potential for develoxment of ground water are present. The areeis in each classification are shown on Plate 9. The general conditions which presently govern the potential for development of ground water within each zone found in this basin are disctissed below. "A" Zone . The "A" Zone areas are situated at locations where permeable beds of the Alturas formation are exposed at the ground surface or are overlain by a relatively thin mantle of Recent valley sediments. In addition, some of these eureas contain burled lava flows which if sufficiently permeable could be producers of confined ground water. Iftider present condi- tions of development the existing potential for rechEurge is more than adequate to provide for anticipated agricultural requirements for water within the "A" Zone areas. "B" Zone . Most of the irrigable landa in the Alturas grovmd water basin are included in the "B" Zone areas. With the exception of the "B" Zone area near Parker Creek, the primary difference between the "B" Zone areas and the "A" Zone areas is the apparent lower recharge opportunity for the "B" Zone areas. This may result in local overdraft conditions wblch in turn would cause Increased puntpiog lifts and decreased yields. ,107- The "B" Zk>ne aorea near Parker Creek is coniposed of Intermediate alluvium and relatively thick near-shore deposits underlain by the Altiiras foznatlon at depth. Recharge of ground vater Is from Infiltration of surface water along the various streams In this area and from precipitation on the near- shore deposits and the lavas to the north. Although the near- shore deposits are generally some^diat less permeable than the Alturas formation, the combination of thickness of the deposits and good recharge opportunity sho\ild allow properly constructed deep wells In most of this area to yield moderate quantities of ground water. "C" Zone . The "C" Zone areas In much of the Alt\iras basin axe tho» In which the thickness or permeability of the water-bearing materials Is g limited or the extent of adjacent recharge areas Is restricted. Jlhe "C" | Zone areas sltixated In Warm Springs Valley subbasln and to the west of the City of Alturas are so classified because the relatively Impermeable Warm Springs tuff Is found at shallow depths. This tuff Is generally a poor producer of ground water and may be up to several hvindred feet In thickness. Hence, well yields will be determined by the thickness of the saturated zone In the overlying materials. In certain areas, wells could be constructs through this tuff and Into underlying water-bearing materials. The "C" Zone area north of Parker Creek Is ccnrprlsed primarily of near-shore deposits and Intermediate alluvium. These materials are usually \mderlaln by Impermeable rocks of the Cedarvllle series. These conditions, along with a relatively poor recharge opportvmlty, result In this zone being a relatively poor area for the developient of ground water. "D" Zone . The "D" Zone areas are located adjacent to outcrops of rocks having low peimeabilities. Because water-bearing siirface materials in these areas are underlain at shallow depths by rock of markedly less -108- permeability, veils located in the "D" Zone areas vould yield only small amoimts of vater. There is also a distinct probability that a well constructed in a "D" Zone area woiild be dry. General. The Alturas formation is the most important geologic formation with regeird to groijnd water develojanent potential within Alttiras basin.. The sedimentary portions of the formation, if siofficiently recharged, visually are capable of yielding moderate to large quantities of groimd water to wells. Except in the areas where the Warm Springs tuff is either exposed at the ground surface or underlies the valley floor at shallow depths, the sedimentary portion of the Alturas formation is adjacent to good recharge ai^as. In general, the degree of ground water development potential at any location within the valley floor is determined by the depth of the sedimentary portions of the Altijras formation underlying the particular location. Within certain areas, permeability and recharge potential are excellent. Here, properly constructed wells should yield large quantities of ground water. Groxmd Water Storage Capacity The ground water storage capacity to a depth of 800 feet in Alturas basin has been estimated to be approximately 7,500,000 acre-feet. How much of this quantity is usable, or how much usable storage exists below 800 feet is not presently known. It is reeisonable to etssime that a significant amount of ground water could be developed. Qtiality of Ground Water The ground water q\iality in the Alturas ground water basin is generally good and suitable for most beneficial uses. Throughout most of the basin these waters are bicarbonate in cheuracter; however, there is a -109- portion of Warm Springs Valley subbasln south of the Pit RLver vhere a«LcLl- tlonal sulfate and chloride Ions are present euad the vaters have a more balanced anion cooiposltlon. The cation content of the ground vater Is predominantly calclim In the vicinity of Altviras and sodlxm In the area of Warm Springs Valley subbasln east of Canby and north of the Pit River. Ea.sewhere In the basin the character varies from calcium to sodium. Water Quality Problems The most significant vater quality problem In this basin Is the large eurea of sodium type vaters In Warm Springs Valley subbasln shovm on Plate 9- These vaters have excessive sodium eidsorptlon ratios and are considered hazardous for Irrigation tise, although generally siiltable for dcnnestlc use. Kelly Hot Springs also pose a vater quality problem, as they produce a sodium sulfate water vhlch Is poor In quality. Analyses Indicate that this vater contains a high concentration of total dissolved solids cold excessive boron and fluoride. This vater Is not recomnended for Irrigation or domestic use. A fev veils scattered throughout Alturas basin contain vaters high In nitrate ; Iron, or boron. The variation of vater quality as veil as the scattered location of these occurrences of poor quality vater Indicate that the Impairments are of a local nature. ConclTislon Alturas ground vater basin apparently has a significant potential for additional ground vater development from aquifers vlthln the Alturas formation. Development of these aquifers In Waim Springs Valley should be done only under the awareness of the x>osslble vater quality problem vhlch exists vlthln a portion of this area. -HO- within the valley floor lands of the Alturas basin, the present requirement for additional irrigation water is highly variable. Within some areas, direct precipitation is the only source of agricxiltviral water, while other areas receive an adeqtiate supply of irrigation water from surface water augmented by storage facilities. Generally, irrigated lands served by direct diversion from non-regulated and some peurtially regulated streams reqixire supplemental irrigation water sometime after the middle of July. If additional acreage were to be put under irrigation, or if crops requiring increased and/ or firmer quantities of irrigation water were planted, an additional source of firm irrigation water would be required in some areas presently considered to jwssess a good irrigation water supply. Under the present level of agricultural development, the ai^as X>ossessing the best ground water development potential are also the aureas where additional irrigation water is generally not needed. This inverse supply- requirement condition generally exists throughout most of the area of irrigable valley lands. Except within areas \mderlain by poor quality ground water, lands requiring a supplemental irrigation water supply, generally can obtain this supply from ground water, but wells constructed for this purpose generally will not be located within areas of best groimd water development potential. It is concluded that the basic data collection activities of the Department of Water Resources should be continued in order to facili- tate future qixantitative eind qualitative asaalysis of the ground water basin. Encouragement should be offered to local agencies in their efforts to develop the ground water potential in the majmer best sxiited to local problems and in accordance with information in this bulletin. -m- I Big Vailley and Round Valley Ground Water Basins Big Valley consists of a broad plain about 13 miles long fix)m north to south, and 15 miles vide from east to vest. Ihe northern portion is in Modoc Coimty and the southern portipn in Lassen County. Big Valley Is bordered by extensive bench lands and gently sloping hills. Surrounding mountains include the Big Valley Jfc^untains to the vest, and Beurber Ridge to the east. The elevation of the floor of Big VeOley is about 4,200 feet. Pit River enters Big Vaaiey from the north and flovs southerly across the valley past the tovns of Lookout and Bieber. Ihe river leaves the valley by vay of a gorge at its southern end. Roxmd Valley is located to the northeast of Big Valley and is considerably smaller in area and slightly higher in elevation than Big Valley. Round Valley is entirely surrounded by mountains. The principeil moimtains are Horsehead Mountain to the northeast, and Barber Ridge to the southeast, separating Round Valley from Big Valley. Ash Creek enters Round Valley from the southeast. It joins Rush Creek in the centreLL portion of the valley and then flovs vestvard into Big Valley. The surface exposvires of the various geologic formations of the Big Valley and Round Valley area are shovn on Plate 10, Areal Geology, Big Valley and Round Valley Ground Water Basins. Plate 11, Generalized Lines of Equal Elevation of Water in Wells in Hear- Surface Aquifers, Big Valley and Round Valley Grovmd Water Basins, Spring I96O, is a generalized picture of the elevation of unconfined or semi -confined groiind vater vithin the ground vater basins. Plate 12, Generalized Lines of Equal Elevation of Water in Wells in Confined Aquifers, Big Valley and Round VeOley Ground Water Basins, Spring 1960, indicates the general elevation to irtiich -113- confined ground water would rise in a well. Plate 13, Potential for Develop- ment of Ground Water, Big Valley and Rovmd Valley Ground Water Basins, presents the preliminary evaluations of the potential for groimd water development within these basins. Geologic Histoiy Rocks exposed in Big Valley and Round VeuLley record geologic history dating hack to the Miocene epoch, 25 million years ago. During the Miocene and Pliocene epochs, these valleys were part of an area of extensive lakes bordered by large volcanoes. The lakes received large volumes of ash and other volcanic debris blown into the water by violent explosions and washed in by tonrential rains. During the latter part of the Pliocene epoch, the crust of the earth began shifting along n\amerous faults. Vertical movement along these faults slowly built the mountains s\irroundixig the present valleys and caused the valley areas to sink. The lakes ■Hhich were present were restricted more or less to the present valley areeuB and the low- lying area north of Lookout. During the same epoch, masses of rhyolite lava formed domes southeast of the veuLley. By the end of the Pliocene epoch, the ancient Pit River had succeeded in cutting through the Big Valley Mountains and had drained the remnants of the Pliocene lake. During Pleistocene time, extensive flows of basalt • spread over parts of the old lake bed and formed the low- lying plateau north of Big Valley. Similar flows covered the southern portion of the veuLley and filled the ancestral canyon of Pit River. The resxolting nattiral dam flooded Big Valley forming another leu:ge lake. This IcLke remained throughout the Pleistocene epoch and ixsssibly was present in the early part of the Recent epoch. Pit River eventually cut through the basalt barrier and drained -lilt- the ]flke. The barrier still heu5 not been completely removed as illustrated by the large svampy areas found in Big Valley today. Water>Bearing Formations Table 11 briefly describes the geologic formations in Big Valley and Round Valley. Of these, the principal water-bearing formations are Pliocene to Pleistocene lava flovs, the Bieber formation, and Recent valley sediments. Pliocene to Pleistocene Lava Flovs. Pliocene to Pleistocene lavas consist of jointed and fractured basalt and occur both north and south of Big Valley. They also cap Barber, Ryan, and Htmter Ridges above Round Valley. The lavaB are in general moderately to hi^ly i>ermeable and act as forebays for ground vater recharge. Near the south end of Big VeuLLey, in the vicinity of Juniper Creek, a Pleistocene basalt flov yields moderate amounts of artesian water to wells and simips. No well data are available for the baseuLt flows at the northern end of the valley. These latter flows may yield moderate to large amounts of ground water •vrtiere there is an appreciable saturated thickness. From Lookout northward along Pit River, the basalts appear to be mostly above the zone of saturation and apparently are too thin to yield large amounts of ground water. Bieber Formation. The Bieber formation underlies all of Big Valley and Roimd Valley, in many places beneath a thin veneer of younger deposits, and also occurs beneath some of the adjacent basalt flows. The Bieber formation consists of leike deposited diatanite, sand, silt, clay, and some gravel. Its thickness is estimated to be at least 1,000 feet and in some areas may be as much as 2,000 feet. It apparently grades downward into imderlying diatomaceous sediments of the Turner Creek formation. The principal aquifers in the Bieber formation consist of beds of white pumiceovus -115- GEOLOGIC FORMATIONS IN BIG VALLEY AND ROUND VALLEY AREA GEOLOGIC AGE APPROXIMATE THICKNESS IN FEET PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS Qb : Unconaolldatodt Intsrbaddad allty clay, and organic muck. Alkali may be prasont. Qal: Unconsolidated, poorly sorted silt and sand contain- ing minor amoxmts of clay and gravel. Alkali may be present Moderately permeable. Ylelda moderate quantities of water to wells. ftf : Unconaolldated, rudely stratified gravel, sand, and silt, with clay lenses. Moderately permeable; may coxi' tain moderate amotmts of fre« and confined water. (^vb! Hi^ly Jointed, vesicular flat-lying olivine basalt flows; contains scoria zones. Permeability ranges from modara%| to high. Acts as recharge tPi) for ground water in Big Vall«yj Yields moderate to large quan* titles of free and confined water to wells in southern pvH of Big Valley. i^b; Unconsolidated to semi- consolidated, interbeddad dlatomite, silt, sand, and some gravel. Apparently grades downward into T\imer Creak formation. Generally of moderate perme- ability. Yields moderate quantities of water to well Moderately permeable. Basalt , acts as forabay for recharge ' to adjacent parts of Big Valley and Round Valley. Kay yield moderate quantities of water to walls. Andeslte is essentially impermeable. Tvr: Light-color rhyollte tuff. 3d rhyolite and Essentially impermeable Tvb ; Jointed, dipping flows of "Taaalt with Interbeds of sand, tuff, and dlatomite. May be equivalent In part to Turner Croak formation. Low overall permeability. Some basalt flows may yield small to modarata amounts of water. Tmtc ! Well bedded sand, silt, cTTatomita, tuff, and mudflowa; minor flows of basalt, ande- slte. Generally low permeability but contains some permeable beds which yield small to moderate quantities of water to wells. 116 sand and black volcanic sand. These sands are highly permeable and occa- sionally are capable of yielding xip to 1^000 gallons i>er minute to veils. However, the beds are usually too thin to yield such leurge amoimts of water. Individxial beds are laterally discontinuovis, but they occ\ir beneath most parts of the valleys. Recent Valley Sediments. Becent valley sediments in Big and Round Valleys include basin deposits, intermediate alluvium, and aUuvieLL fans. Ihe basin deposits consist mainly of organic muck, silt, clay, and some sand. They occupy the low-lying, iKJorly drained areas. The deposits are of low permeability and do not yield appreciable amounts of water to veils. The intermediate alluvium consists of up to about 200 feet of send EUid silt vith lenses of gravel and clay. 'Qiese deposits occupy more elevated, better drained portions of the valleys. The intermediate alliiviiaa is generally of moderate permeability but may be highly permeable where large gravel lenses occur. In areas where the intermediate euLluvium is of sufficient thickness, it may provide large yields of water to irrigation veils. The alluvial fans occur in only a few small areas in the two valleys. The fans consist of i>oorly bedded gravel, sand, silt, and clay. The fans cure not important water producers in this area. They may, however, locally yield moderate amounts of water to wells. Influence of Geologic Strijcture on Grotmd Water The geologic structure of Big Valley and Ro\aid Valley is that of a series of depressed fault-blocks svirrounded by uplifted tilted fault-block ridges as shown on Plate 10 and Figure 13. Subsurface features shown on Figure 13, as well as locations of many faults in Big Valley, as shown on -117- 662 *omii6!H $0 ifBnois *f01 B63 ilM. \h\\\W = i 'fill wnivQ sasn laaj ni NoiiVA3i3 118 Plate 10, are from lnte]T>retation of data from a geophysical Bvanrey of the valley floor area of Big Talley and from exploratory test holes drilled in Big Valley. Figure l4 was developed from veil log data. Ihe main fault trend is to the northvest with a subordinate system trending to the northeast. The fault -blocks forming the Big Valley Ifovintains, Barber Ridge, and Ryan Ridge eure tilted to the east. The Bieber formation has been deformed into gentle folds apparently associated with faulting in Big Valley. The ridge east of Round Valley has been deformed into a broad arch. a S ELEVATION IN FEET U.S.6.S. DATUM 1 5000 4000 3000 ( for loco 'i ! ^ 1 Zone of Flowing Wells Pleistocene Bosolt t 1 ' Basin Deposits \ ^^Bieben 1 1 "ormotion 1 ~ Bieber Formation --=:i"&--r-'^- ' ^f^^Hf^-r^Xx. 1 1 1 1 1 ) 1 LENGTH ion of section. 2 IN MILES 3 4 Figure 14. GENERALIZED GEOLOGIC SECTION B-B' BIG VALLEY GROUND WATER BASIN -119^ The numerous faults may act eus partial ground water barriers, although In a few places they serve as paths for the upward migration of heated ground vater. Fault barriers to ground vater movement are fozmed by offsetting permeable beds and by the creation of impervious gouge along the fa\ilt plane. Ground vater Is often forced to the surface along these barriers, forming springs. Many springs of this type are found In the area. Hxe two hot spring areas In Big Valley are located close to faiilts. The hot springs are formed as a restilt of deep clrctilatlng ground vater becoming heated and mixing vlth mineralized upward moving vater of probable magmatlc origin. Recharge and Movement of Ground Water Upland recharge areas are shown on Plates U and 12. Ground vater vlthln the sediments of Big Valley and Round Valley Is recharged primarily from the upland recharge areas of Pliocene and Pleistocene basalt located south and aorthwest of Big Valley and vest of Round Valley. The upland recharge area shown to the north of Round Valley and Indicated eis 'WM Indeterminate on the plates consists of a portion of the Turner Creek fozma- tlon. At this location, permeable beds In the Turner Creek formation dip towaird the south and apparently pass beneath the valley floor. Ground vater contained In these beds appears to recharge the sediments In the northern portion of Round Valley. In both valleys, a secondary, but highly slgnlflcaall amount of recharge Is derived from surface vater Infiltrating the Recent sedl^ ments along the numerous streams i^blch flow Into and through the valleys. The mean seasonal precipitation on the floor of Big Valley ranges from less than 10 Inches near Hot Springs trlangulatlon station, to In excess of l8 Inches near the margin of the valley floor. The year to year variation of precipitation Is considerable. At Bleber, the mean seasonal -120- precipitation is I6.TJ inches, but the recorded maximi;m and minimum precipi- tation is 28.24 and 8.69 inches, respectively. Mean seasonal precipitation on the upland recharge aree^ is also subject to considerable variation, the maximum and minimum values being somevhat higher than those of the valley floor. The mean seasonal precipi- tation over most of the upland recharge areas ranges from I8 to 22 inches. On the floor of Round Valley, the mean seasonal precipitation is about 16 inches. Hie size of the valley floor apparently is not siifficient to cause a significant change of precipitation from one side of the valley floor to the other, although precipitation from thunder storms is quite variable. Long-term maximum and minimian precipitation values are not avail- able for any station within Round VsLLley, but the magnitude of these varia- tions should approximate those of stations in Big Valley. U^n the recharge areas to the vest of Round Valley, the mean seeisonal precipitation is estimated to range from I8 to 2i|- inches. Here, as in other nearby upland recharge areas, the variation of precipitation from year to year is considerable. Generalized lines of equal elevation of water in wells within Big Valley and Round Valley are shown on Plates 11 and 12. The lines on Plate 11 indicate the general direction of movement of the near-surface ground water body underlying most of the valley floor areas. This body is presently Intercepted by wells of depths generally less than 70 feet. The lines on Plate 12 Indicate movement for a portion of a deeper, confined grovnad water body within Big Valley. Ihls body Is generally intercepted by wells of depths generally in excess of 200 feet. A discussion of the move- ment of ground water within each of these basins is given below. -121- Big Valley Ground Water Basin. Within the portion of the valley- floor near Adln, neeur-surface ground water moves toward Ash Creek where It Is paurtly Intercepted. In axeas where this ground water body occurs within the Bleher formation, It is under various degrees of confinement. Where It Is In the Intermediate alluvium and basin deposits, it is in an essentially unconflned state. To the west of the confluence of Ash Creek and Willow Creek, the direction of movement of this ground water body is westerly toward Pit River. The direction of movement of the upper ground water body north of Lookout is generally from the s\irro\mding foothills toward Pit River. Between Lookout and Bieber, a jjortion of the ground water is Intercepted by nianerous stream channels, and the remainder moves southerly toward Bieber under a relatively flat gradient. The two areas with lines of equal elevation of water in wells shown on Plate 12 in the vicinity of Bieber and Adin, generally represent the piezometrlc surface of a combination of various confined gro\md water bodies. In the area generally south of Juniper Creek, these lines apparently represent the piezometrlc surface of confined ground water moving south- westerly in a buried lava flow cuad an underlying permeable sand bed of the Bieber formation. Recharge to this ground water body is apparently from the basalts eJ-ong Jixaiper Creek. The lines in the vicinity of Bieber apparently represent the piezometrlc surface ©f confined ground water within certain permeable beds of the Bieber formation. Location and method of recharge to the deei>er aquifers in this area are uncertain. Mar Adin, a few wells intercept a confined ground water body, nie direction of movement in this body is apparently toward the west. There appear to be several separate groxmd water bodies within the Bieber formation which eure not included in the representations -122- on Plates 11 and 12. In addition to these bodies, a relatively small quantity of mineralized groixnd water rises along faults in particular areas. Ro;md Valley Ground Water Basin. East of Ryan Ridge, the direction of movement of the near-sxirface ground water is generally similar to that of the surface streams. As in Big Valley, the degree of confinement varies from locally confined zones in the Bieber formation to essentially unconfined conditions within the intermediate alluvium and basin deposits. Deeper ground water bodies, not included in the representations on Plate 11, also exist within this portion of Round Valley. These bodies are confined and cause wells in some areas to flow. South of Ryan Ridge, the near-surface ground water presently inter- cepted by wells is moving in a southeasterly direction from the Pliocene basalt of Barber Ridge toward Ash Creek. The Turner Creek formation of Ryan Ridge is a barrier between ground water moving downslope throu^ Barber Canyon and ground water in the remainder of the veQ.ley. There is hydraulic continuity between these two ground water bodies in the immediate vicinity of Ash Creek, at the mouth of Barber Csinyon. Some subsurface move- ment of ground water from Round Valley toward Big Valley exists through the narrows of Ash Creek near Adin. Present Use of Ground Water The valley floor of Big Valley comprises 93>500 acres, about 88,000 acres of which are classified as irrigable. Approximately 2Ji-,000 acres are ciirrently irrigated during the early spring by waters diverted from unregu- lated or partially regulated streams. As frequent flooding also occurs during this portion of the growing season, the type of crops grown on the irrigable lands of the lower portion of the valley floor are limited to those possessing a tolerance to annual inundation and prolonged high water -123- tatile conditions. During the latter i>ortion of the growing season, surface water irrigation supplies usually are insufficient to maintain optimum soil moisture conditions. Ground water development for the purpose of supple- mental irrigation water supply has been attempted with various degrees of success within the valley. During I958 only l4o acres of cultivated crops received their total or partial irrigation water sijpply from pumped groiind water. However, several of the irrigation wells were inoperative during 1958, the year the survey of irrigated lands was conducted. The approximate yields of I6 irrigation wells located during 1957 ranged from 190 to 900 gallons per minute, usually with considerable drawdown. Of the lf20 wells located during this period, the majority of the active wells were utilized for domestic and stock watering purposes. ! Most of the irrigated lands within Round VsuLley receive irrigation water from gravity diversion of the unregulated flow of Ash Creek and JRush Creek. The irrigation water sxipply for most of the remainder of the irri- M gated lands is either from springs or from four flowing wells. The acreage Irrigated by flowing wells Is estimated to be approximately 10 acres. The above irrigated lands con?)rise only a small portion of the irrigable lands within the 8,300 acres of the valley floor of Round Valley. Most wells located in Round Valley are used either for domestic or stock watering uses. Only the four flowing wells were used for irrigatioi purposes diiring 1957. The yield frcm each of these flowing wells is approxi- mately the same and is estimated to be about 10 gallons per minute. Ground Water Development Potential Within the valley floor area of Big Valley and Roimd Valley ground water basins, three of the four zones of potential for development of ground water are present. The area of the valley floor in each of the three -121^- i classifications is shown on Plate 13. The general conditions -vrtiich govern the potential for develojHnent of ground water within each zone found in this basin are discussed below. Big Valley "B" Zone. The southernmost of the three "B" Zone areas of groimd water develojanent potential within Big Valley apparently contains numerous sand beds of the Bieber formation. There is also the possibility that a thin, buried permeable lava flow may extend into the eastern part of this ar«a. It appears that there is adequate recharge to the water-bearing materials in this area. The "B" Zone area near Lookout is composed of coeirse intermediate alluvi€LL materials deposited by Pit River and Taylor Creek. The depth of these materials is probably about 200 feet. Underlying these materials arc lake dejxjsits of low permeability belonging to the Bieber and Turner Creek formations. The "B" Zone area, along Widow Valley Creek is ccmposed of coarse stream deposits up to 100 feet in thickness. Recharge to ground water within the two northerly "B" Zone aoreas is from infiltration of svirface water silong the stream channels and by subsurface movement from Pliocene and Pleistocene lavas located north of the areas. Yields of properly constructed wells within the "B" Zone areas are expected to vary considerably because of variations in thickness and number of i)ermeable beds intercepted, and becavjse of differences in permeabil- ity and recharge opportunity of the individiial beds. Big Valley "C" Zone. Most of valley floor lands in Big Valley are classified as a "C" Zone area. Ihe geologic materials within this area are primarily lake deposits belonging to the Bieber formation which are overlain in part by a relatively thin mantle of Recent sediments. Ihe over- lying sediments are frequently too thin to yield substantial quantities of -125- ground vater to veils. The nvmber of sand beds in the Bieber formation is apparently less than in the "B" Zone surea south of Bieber, considerably- reducing well yields in the area classified as "C" Zone. In the vicinity of Juniper Creek, there is a permeable basalt flow interbedded with sedi- ments of the Bieber formation. This lava is apparently relatively thin and probably would not produce large quantities of gro\ind water to wells. Re charge available to the "C" Zone area from infiltration of surface water and from lateral movement from surrounding lava areas probably exceeds the quantity of ground water which the aquifers can transmit to wells in the vallt floor area. Therefore, the expected yields of wells in this area generally are sufficient only for domestic, stockwatering, and limited irrigation uses Big Valley "D" Zone . The "D" Zone areas are located adjacent to areas of impermeable rock. The intermediate alluvium, alluvial fan, and lavas found in the "D" Zone axeas are permeable but because they are \jnder- lain at shallow depths by impermeable rocls., wells in these areas would yield only small amounts of ground water. Big Valley Contiguous Areas . Wells drilled in certain portions of the upland recharge aj:«as could yield moderate to large quantities of groiind water, depending on the permeability of the materials interceirted. Within particular portions of the upland recharge areas, ground water yields may be greater than those of wells drilled in the valley floor. The depth to ground water, however, is generally greater in the upland areas than in the valley floor areas. Round Va3Lley "B" Zone . The "B" Zone area in the vicinity of the confluence of Rush Creek and Ash Creek is composed of coarse intermediate alluvial material deposited by these streams. The depth of these materials may be about I50 feet. Underlying these materials are less permeable lake -126- ¥ ¥ deposits belonging to the Bieber and Turner Creek formations. Recharge to grovmd vater in this area is apparently from infiltration of siirface water along the stream channels. Round Valley "C" Zone . Most of valley floor lands in Round Valley are classified as a "C" Zone azrea. The geologic materials in this area consist primarily of lake deposits belonging to the Bieber formation vhich are overlain by thin deposits of Recent sediments. Ground water yields from wells in this area will depend primarily upon the thickness of the intercejrted permeable beds. Recharge of ground water in this area is from infiltration of surface water and from percolation from adjacent upland recharge areas. As in Big Valley, the recharge opportunity to grovmd water within this area is apparently better than the ability of the aquifers to transmit ground water. Round Valley "D" Zone . The "D" Zone eureas are located adjacent to areas of iinpermeable rock. The intemediate a1 1 uvixm and alluvial fans within these areas are quite permeable, but they appear to be too thin to yield any substantial quantities of ground water. General . In the valley floor area of both Big Valley and Round Valley ground water basins, the potential for developnent of wells with yields sufficient for irrigation purposes is limited, due to the fact that the developable aquifers are not sufficiently permeaole. The potential yield should be sufficient, however, for anticipated demands for domestic and stock purposes in "C" Zones, and may be greater in "B" Zones. Within portions of the upland recharge area northwest of Big Valley, ground water yields from deep wells probably will exceed the average yield of the deep wells within the valley floor, but the depth to water will generally be greater in these upland areas. -127- One area of exception to the liialted potential for irrigation veil development within Round Valley is located near the confluence of Ash Creek and Rush Creek. Here a limited number of properly constructed irrigation wells probably could be located and developed. However, too heavy develonnent in this area would resvdt in falling ground water levels. Groiind Water Storage Capacity The ground water storage capacity to a depth of 1,000 feet has been estimated in Big Valley to be approximately 3,750,000 acre-feet. Storage capacity in Round Valley has been estimated to be 120,000 acre-feet to a depth of 200 feet. How mxich of these quantities are usable or how much storage exists below the depths of 1,000 and 200 feet, respectively, is not presently known. It is reasonable to asstane that a significant amount of ground water could be developed. < n Quality of Ground Water Ground waters in Big Valley and Round Valley are generally excel- lent in mineral quality and sxiitable for most beneficial uses. Bicarbonate is generally the predcxninant anion in these waters. The cations are \isually well baleuiced although sodium predominates in some well waters. ISae sodi\mi type waters are found scattered throughout the valleys rather than in a particular portion of the basin. Two hot springs emd one well in Big Valley basin yield poor quality thermal waters. The well and one of the springs are located about 6 miles east of Bieber. The other spring is located 2-l/lt- miles northecust of Bieber. These poor quality watears are sodium svilfate in character and are not recommended for either domestic or irrigation use. -128- Water Quality Problema The most significant vater quality problem In Big Valley Is that posed by the poor quality thermal waters found In the hot springs areas. Ihese vaters have high electrical conductivities and excessive concentrations of fluorides and boron. They are considered as hazardous for either danestlc or irrigation uae. These poor quality waters can impair adjacent ground or surface waters if they are discharged freely at the ground sxirface or if they are permitted to migrate into them through Improperly constructed or abandoned wells. One well located 3-1/2 miles west of Adin produces water containing sursenic in concentrations exceeding 0.1 ppn. This water does not meet drinking water standards and Is not reconmended for domestic use. This occurrence is apparently localized and the concentration is low enough that It could be reduced to a safe level through dilution. Ground waters extracted from several wells scattered throughout the basin contain excessive nitrates and are considered to be hazardous for domestic use. Biese occurrences appear to be the result of localized impairment. Condvuaion Ground water development for irrigation purposes by deep irrigation wells within Big Valley and Round Valley appeeirs to be limited by the generally low permeability of aquifers within the Bieber formation. Ground water of good quality is available except in certain localized areas where hot springs or IsdLated wells produce waters of poor quality. It is concluded that the basic data collection activities of the Depeurtment of Water Resources should be continvied in order to facilitate future quantitative and qualitative analyses of the ground water basin. Encouragement should be offered to local agencies in their efforts to develop the ground water potential in the manner best suited to local problems and ]a aceordaoce with information in this bulletin. -129- Fall River Valley Groiind Water Basin ffi- Pe^ll River Valley Is located In eastern Shasta Co\uity and western Lassen Coan'l^y. The valley Is about 7 miles long and l6 mil es vide and lies at an elevation of about 3,300 feet. It Is bounded on the east by the Big Valley Mountains stnd on the vest by a ridge consisting of Soldier and Saddle Mountains. IThe northern and southern boundaries are poorly defined because of extensive lava flovs of low relief. Fall River is the major stream draining the valley. It flovs In a southerly direction to its confluence vitb Pit River neeur the tovn of Fall River Mills, in the south- western part of the valley. Pit River enters the valley on the southeast. It flovs past the towns of Flttville and McArthur to its confluence with Fall River and then flows southwesterly out of the valley. There are only a fev tributary creeks in the valley. One is Bear Creek in the northwestern part of the valley, the other is Beaver Creek in the southeastern portion. The surface exposures of the various geologic formations of the Fall River Valley area are shown on Plate ik, Areal Geology, Fall River Valley Ground Water Basin. Plate 13, Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Fall River Valley Ground Water Basin, Spring i960, presents a generalized picture of the elevation of groimd vater vithln the ground vater basin. Plate 16, Potential for Develoiment of Ground Water, Fall River Valley Ground Water Basin, presents the preliminary evaluations of the potential for ground vater develoiment vithln this basin. Geologic History During the Miocene epoch. Fall River Valley vas the scene of many vQlcanic eruptions. For millions of years, lava emd ash accumulated layer upon layer, creating a broad viQlcanlc plateaa. During the late flioeene and -1.31- early Pleiatocene epochs, recurrent earthquakes broke and uplifted the eastern peurt of the plateau to form the Big Valley Moxmtains; the western pcuTt sank to form Fall River Valley. The valley was soon occupied by a large lake which originally may have drained to the north into Klamath River. Near the end of the Pleistocene epoch, volcanism north of Fall River Valley produced lavas which covered the northern end of the valley. Subsequently, the lake overflowed through a gap at the southwestern edge of the valley. Erosion of this outlet eventually drained the l&ke, carved Pit River Cajiyon, and left the valley much as we see it today. Water- Bearing Formations Table 12 briefly describes the geologic formations in Fall River Valley. Of these, the principal water-bearing formations are Pliocene to Recent lava flows, lake and near-shore deposits, ajid Recent valley sediments. Pliocene to Recent Lava Flows . Basalt flows of Pliocene to Recent age are xisually highly fractured and frequently contain many scoria zones; lava tubes are not uncommon in the Recent basalt flows. The overall x>erme- ability of the Recent basalt is high to very high. Permeability in the Pleistocene basalt is moderate to high, and it is low to moderate in the Pliocene bajBalt. This decrease in permeability with an increase in age 1b due to weathering of the rock to form clay which seals the openings in the rock. Although there is scant information regarding wells in the various lava flows, the following observations can be made. RiBcsnt basalt partly overlies lake sediments at the northezu end Fall River Valley. A second eurea of simlleu: Recent basalt is located south of McArthur. Fall River and its associated streams and lakes &re fed by -132- I B I GEOLOGIC FORMATIONS IN FALL RIVER VALLEY GEOLOGIC AGE PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS Highly perneabla, but usually above sone of saturation. Yields water to springs. Low permeability^ unimportant as source of ground water. ^al ! Ifticonsolldated silt, sand, and gravel along stream chan- nels and on flood plains* Permeability ranges from moder- ate to high. May yield moder- ate quantities of water to shallow wells. Qf ; Ifticonaolidated, poorly stratified gravel, sand, and silt. Moderately permeable. May con- tain moderate amounts of free and confined water. Qrvb ybt Highly jointed, vesicul Ivine baaalt. Includes inder cones containing unco olidated volcanic cinders* Highly permeable. Acts to re- charge north part of valley. Provides copious quantities o water to springs, streams, and lakes at north end of valley. Qps ! Partly consolidated aand, silt, and clay. Frequently cross-bedded and of a bluish color. to ■ alls pi ! Partly consolidated, inter bedded clay, volcanic ash, dlatomite, and fine sand. Interfingers with near-shore deposits. Slightly permeable. Occasional aand beds yield small quanti- ties of water to wells. Acts as confining layers to ground water in buried lava flows. Highly permeable but of small areal extent and hence unim- portant as source of ground water. Permeability ranges from moder- ate to high. Yields large quantities of confined water where interbadded with lake deposits. Tpl ; Horlsontally bedded de- posits of dlatomite, with lesser amounts of sand and gravel. Pound only near Lake Brltton, Some beds are moderately per- meable; may act aa routes of subsurface outflow from valley. Essentially in^jermeable. Tpyb ; Plows of baaalt with sobm interbeddad pyroclaatio rocks. Low to moderate permeability. May yield small quantities water* TpTp ! Beds of tuff. Essentially Impermeable. Tvbi Jointed, dipping flows of Sasalt with Interbeds of sand, tuff, and dlatomite. Low overall permeability* Some basalt flows may yield small amounts of water* Twvbt Plows of baaalt. Very low permeability. May yield small amounts of wate numerous springs which occur along the front of the Recent basalt flows at the north of the valley. The presence of large springs is indicative of the high permeability and vast ground water storage capacity of these rocks. According to the United States Geological Survey, five groups of springs in Section I9, Township 38 North, Range k East, M.D.B.SeM. flow from the Recent basalt and form the headwaters of Fall River. These springs have an estimated combined flow of about 150,000 gallons per minute. Other springs also flowing from these lavas form Spring Creek, Eastman Lake, Tule River, and Big Lake. The total measurable flow of springs iss\iing from the Recent lavas has been estimated to be about ii-00,000 gallons per minute. Most of the Pleistocene basalt found on the east side of the valley appears to be highly permeable. In contrast, portions of the Pleistocene basalt found in other areas have a somewhat lower permeability and an upper siirface that is sufficiently impermeable that small reservoirs have been constructed thereon. The principal importance of most of the Pleistocene basalt is as a gro\ind water recharge area. Wells located in this basalt may provide moderate yields for domestic emd stock purposes. However, Pleistocene lavas where buried within lake ajad near- shore dejxjsits may yield large qiiantities of confined ground water to wells. The Pliocene basalt provides some groxmd water recharge to the southern part of Fall River Valley. Althotigh not suitable for irrigation well development, some areas of Pliocene basalt may yield sufficient water to wells for domestic or stock use. In addition, some perched groiind water may be found locally in this unit. Lake and Near- Shore Deposits . Lsike deposits, up to 7OO feet thick, are found in the northern part of Fall River Valley where they extend some distcmce northward beneath a cover of Recent basEilt as shown on Figure 11 -13^- 663 ^omqSiH S n ^1 ON pooa /4unoo sc Jt|0J3 p»j»qiuii. < _ en 7 < o OQ \- oc p UJ liJ 1- - UJ UJ N _l -1 < oc UJ oc ZUJ UJ > <.') cc lO -J « -I wniwQ sosn i33j ni NoiivAana l^S Near Pit River, the lake deposits interfinger with the coeurser gralixecl near- shore deposits. The lake deposits as a whole are only slightly permeable. OccasiOE sand beds yield small quantities of ground water to wells. In contrast, th|i near-shore deposits are moderately permeable and yield moderate quantities oi water to wells. A number of irrigation wells are located in areas of lake and near- shore deposits. These wells yield fair to large quantities of ground water. However, most of the ground water apparently is derived froa buried lava flows rather than from lake and near-shore deposits. Recent Valley Sediments . Recent valley sediments Include alluvial fans, intermediate alluviiom, and basin deposits. In general, alluvial fans eire moderately permeable and serve chiefly as gro\ind water recharge areas. Water cascading down the canyons infiltrates the fans and then percolates valleyward. Wells located on the alluvial fans may yield moderate quant It ie of ground water. Most of the intermediate alluviim in Fall River Valley is too thiS to be of major significajace to ground water. Only deposits along Bear Creel and Pit River show any promise of substantial ground water development. In these areas the intermediate alluviijm may reach a maximum thickness of 100 feet and may yield moderate qtiantities of gro\ind water to Irrigation vel ^ Overlying the lake deposits in the vicinity of McArthur Swamp and Big Lake are Recent basin deposits which may be up to 20 feet in thickness. The deposits are of little importance as a source of ground water. Any significant amounts of ground water from wells located on basin deposits Is derived from underlying materials. -136- Influence of Geologic Structxare on Groupd Water The geologic structure of Fall River Valley is illustrated on geologic sections A-A' and B-B' shown on Figures 15 and l6, respectively. Basically, the valley is a northvrest-trending fault trou^ in which a group of blocks has moved downward between two groups of elevated blocks. The volcanic rocks which underlie the valley also have been tilted and broken into several smaller blocks. There sure at least three faults or fault systems passing beneath the lake deposits in Fall River Valley. One fault passes beneath McArthur and has the greatest apparent displacement. The lava flows here have been offset several hundred feet, the west side having moved downward relative to the east side. A group of three parallel faults are located north and west of Glenburn. Rocks on the east side of \\ each of these faults are offset downward about 200 feet. There is no evident displacement along these faults in the Recent lavas north of the valley floor. A third fault branches from a faiilt along the east side of the valley and continues beneath the valley floor in a northwesterly direction beyond the east end of Big Lake. The total offset along this fault appears to be about I50 feet downward on the west side. The general effect of faulting in the volcanic rocks has been the creation of shattered permeable zones which may serve as vertical and/or lateral paths for ground water movement. Because the sediments in Fall River Valley are essentially horizontally bedded, these percolation paths may be of great importance to the recharge of the deep aquifers in the valley. On the other hand, faulting within the sedimentary deposits may tend to create ground water barriers by realigning beds of different I>ermeabilities . -137- FALL RIVER VALLEY 5g£ LENGTH IN MILES See Plate 14 for locotion of section Figure 16. GENERALIZED GEOLOGIC SECTION B-B' FALL RIVER VALLEY GROUND WATER BASIN Recharge tmd Movement of Gro\md Water Tbe upLfiuid recharge areas ^ shown on Plate 15, are ccnrposed of extremely permeable lavas of Pliocene to Recent age. Precipitation infiltrates these i«charge areas and flows valleyward to recharge the aq^lifers beneath -i the valley floor area of the ground water basin. Mean seasonal precipitation .- J ranges from a little over 15 Inches on the valley floor to about k2 inches 1 at the northwesterly boundary of the drainage area of the valley. In the i 1 southwestern portion of the drainage area, precipitation ranges from l6 to 22 | i Inches. Precipitation varies from a minimum of about 10 Inches to a maximum | of slightly over 30 inches at Fall River Mills. Similar variations can be expected throughout the valley area. The extremely i)ermeable and extensive recharge areas act as ground water storage reservoirs and even out *138- the variations in supply. Residents state that it takes about five years for the effects of a year of either high or low precipitation to show up in the water supply of the valley. The ground water basin in Fall River Valley contains both unconfined and confined ground water bodies. The sediments which comprise most of the groimd water basin are generally saturated to within a few feet of the ground surface. Available ground water level data indicate that there is a shallow, imconf ined ground water body moving toward Fall River from the west and toward Pit River from the north and south. Plate 15 shows two conditions which require explajiation. The slight groxmd water depression located north of Pittville is a local condition probably due to the pumping of several wells located in this area. Whether or not the faults in this area influence the shape or size of this depression is not definitely known. The ground water trough southwest of Glenbum may be due to overpumping during a period of insufficient recharge. Flowing wells, which indicate the presence of confined aquifers within the bedded leike sediments, are common along the eastern edge of the valley. Seme of these confined aquifers may be beds of sand and/ or gravel; but for the most part, they consist of highly permeable lava flows which have been buried by valley sediments. Many of the flowing wells in this area have leaky casings or are generally in poor condition, hence piezometric surfaces axe often unmeasurable . The slopes of the confined water bodies appear to rtjughly parallel that of the ground water table. Due to a lack of ground water elevation data, there is a considerable area where the direction of gro\uid water movement is \inknown. Long-time residents of the valley report that some 30 years ago, south of ^fcArthur, a steam drill rig encountered sedimentary materials below a lava flow at a depth exceeding 7OO feet. This -139- veil, which reportedly flowed, is the only evidence for the existence of ground water at such depths. Tremendous quantities of ground water, averaging 800 to 1,100 second- feet, are transmitted through the highly permeable Recent basalts north of Fall River Valley and are largely discharged by springs at the headwaters of Fall River. Smaller springs along the east ajid south edge of the valley are apparently supplied in the same manner. Springs found eQ.ong the bajiks of Pit River are the result of the interception of the water table and the ground surface. These springs confirm the direction of ground water movement in near- surface aquifers from uplemd recharge areas to the springs. Present Use of Ground Water The portion of Fall River ground water basin which is overlain by valley floor lajids is approximately 53^000 acres, all considered to be irrigable. Because of prior rights to most of the surface water for power development, there is a lack of firm surface water supply and only about l6,000 acres are presently irrigated. Rivers ajid creeks furnish a major portion of the irrigation water, but a significant amount is pumped, from ground water. Information gathered during interviews in 1958 *uid 1959 indicates that about 1,300 acres were entirely irrigated by ground water. Well drillers reports ajid field investigations indicate that more euad more groiuid water is being developed each year. Currently, there axe about 50 irrigation wells and about I90 domestic and stock wells in F&ll River Valleyj The wells used for irrigation extract S^ percent of the water pumped. Irrigation wells in Fall River Valley yield highly variable quant itl^ of ground water depending primarily upon the depth and ability of underlying aquifers to yield water. Competent construction and development of wells also is important in obtaining high yields. Good irrigation wells yield 'ikO- 1,CXX) gallons per minute or more, and records show that yields of 2,300 gallons i)er minute are possible. However, in certain peurts of the ground water basin, yields of more than a few gal Ions per minute are probably luxattainable . Ground water storage capacity in the basin is large and conditions of recharge of groimd water are excellent. The. yield from the less i)ermeable formations is low and fairly high pumping lifts are required to obtain a desired quantity of water. Groimd Water Development Potential Within the valley floor area of Fall River Valley all four zones of potential for development of ground water are present. The area of the valley floor in each classification is shown on Plate 6. Available ground water data were ins\ifficient to determine the iKJtential for groxind water developnent in certain areas. The general conditions -vrtiich presently govern the potential for development of ground water within each zone found in this basin are discussed below. "A" Zone . The potential for gro\Jind water development in the "A" Zone areas depends upon the interception' by wells of the highly permeable lavas interbedded within the laJce sediments. Proi)erly constructed wells of 300 to UCX) feet in depth shovild furnish fairly high yields within these areas. Wells in these areas if supplied primarily from the lake sediments rather than the permeable lavas will require somewhat higher pumping lifts to develop the same yield. "B" Zone . Available information indicates that most of the irrigable land in Fall River Valley is located within areas classified as "B" Zone. Properly constructed wells several hundred feet in depth shotild be able to supply most irrigation requirements. These wells will be supplied by ground water contained in the lake and near- shore deposits. If permeable interbedded J.avas are encountered, the yield woiold be considerably increased. -Ul- "C" Zone . Restricted irrigation yields from wells located in the "C" Zone areas are possible but shoxild not be expected. The underlying, relatively thin quantities of intermediate alluvium, lake, and neaj:-shore deposits, and the limited opportunity for ground water recharge, restrict the x>otential yield in these areas. "D" Zone . The "D" Zone areas have the poorest ground water develop- ment potential in Fall RLver Valley. Wells located in these areas are not expected to produce more than limited domestic or stock supplies. Wells I located close to faults or bedrock areas may yield little or no gro\ind waterJ; General . The combination of excellent recharge opportxmity and m relatively high precipitation make the oyerall ground water development ^ potential in Fall River Valley good. A large area in the center of Fall Ri-w Valley has not been evaluated as to ground water development potential due 1^ lack of data. It is estimated that this area ranges from "A" Zone potential in the northern peurt to "C" Zone in the middle and "B" Zone in the southern part. Ground Water Storage Capacity The groxmd water storage capacity to a depth of ifOO feet has been estimated to be approximately 1,000,000 acre-feet. How much of this qiiantity is usable, or how much usable storage exists below i+00 feet. Is not presently known. It is reasonable, however, to assume that a significant amount of ^, ground water could be developed. m Q^ality of Ground Water The groxind waters in Fall River Valley are generally excellent in quality ajid suitable for most beneficial uses. The waters in the central portion of the basin are mostly sodium bicarbonate in character, while those -lll-2- along the i)eriphery are predominately calcium magnesium bicarbonate. Through- out the western portion of this basin, approximately 30 percent of the wells produce ground waters containing concentrations of Iron exceeding that recommended for domestic waters. Water Quality Problems The only significant water quality problem which cturrently exists in Fall River Valley is the high iron content of some of the well waters in the western portion of the basin. These concentrations of iron do not consti- tute a health problem, but do impair the taste and tend to stain la\mdry and porcelain fixtvtres. Although these ground waters are not ccorpletely suitable for domestic use, they are suitable for Irrigation use. A few wells scattered throughout the baaln yield waters containing nitrate ion concentrations exceeding drinking water standEurds, and these are not recommended for domestic use. These waters axe, however, suitable for irrigation. The nature and distribution of these nitrates indicate that they are the result of localized water quality Impairment. Conclusion The development of ground water as a sovirce of supplemental supply for irrigation appears promising. Much of the existing and potential use of water in valley floor areas adjacent to the rivers of Fall River Valley is and will be from ground water, as surface water rights are completely obligated. Generally speaking, adequate irrigation yields may be expected from the "A" and "B" Zone areas, shown on Plate 6. The development of additional ground water in sufficient quantities for irrigation use in these zones depends largely on the selection of proper well construction procedure and competent well development practice. -l»«-3- It is concluded that the Department of Water Resovtrces should continue its "basic data collection activities in order to facilitate futm-e quantitative and qualitative analyses of this ground water basin. Interested local agencies shoiild be encouraged in their efforts to develop the ground water potential in the manner best suited to local problems and in accordance with information in this bvilletin. -lUh- Sierra, Mohavk^ and Hxanbug Valleys Ground Water BaBlns Sierra, Mohawk, and Humbvig VsuLleys are located in Southern Plumas County £ind Northern Sierra County. The veQJLeys jure situated in the upper watershed area of Middle Fork Feather River. The central i)ortion of Sierra Vsilley covers an area roughly 12 miles square. Southwesterly of this central portion, there is an arm of the valley •vrfiich extends southerly over an airea roughly ^ miles long euid from ^4- to 5 miles wide. The average elevation of the floor of Sierra Valley is ^4^,900 feet. Middle Fork Feather River heads in Sierra Valley and is formed by the confluence of several streams draining the surrounding upland area. Little Last Chance Creek is a major tributary to Middle Fork Feather River. Other tributaries include a network of small streams and channels flowing in a northerly direction through the southern portion of the valley. Middle Fork Feather River flows out of Sierra Valley at its northwestern comer. The river flows throvjgh a short gorge into Humbug Valley. Humbug Valley is about 6 miles long, along a northeast-southwest axis, and about 3 miles wide. The floor of the valley lies at an elevation of about ^,850 feet. To the northwest is Penman Peak, having an elevation of 7,197 feet; to the southeast is Beckwourth Peak, having an elevation of 7,255 feet. Middle Fork Feather River flows southwesterly through the valley. Its major tributaries in this valley are Humbug Creek and Willow Creek. After leaving Humbug Valley, Middle Fork Feather River drops through another canyon into Mohawk Valley. Mohawk Valley is oriented in a northwest-southeast direction. The valley is rotighly 8 miles long and 2 miles wide. Its floor lies at an eleva- tion of about ^,500 feet. Penman Peak is to the north and Beckwoxurth Peak is to the east, \rtiile the main crest of the Sierra Nevada is to the west. This crest rises to 7*8l2 feet at ^ft. Elwell and 8,10? feet at Haskell Peak. Middle Fork Feather River enters Mohawk Valley near the mid-point of its northeastern side. It then joins Sulphur Creek, turns noirthwesterly, and leaves the valley by vay of a canyon at its lower end. Other tributaries to Middle Fork Feather River include Frazier Creek, Gray Eagle Creek, and anith Creek. Surface exposures of the varloxis geologic formations of the Sierrai Mohawk, and Humbvig Valleys region are shown on Plate 17, Areal Geology, Sierra, Mohawk, and Humbug Valleys Ground Water Basins. Plate l8. Generalized Lines of Eqtial Elevation of Water in Wells in Near-Surface Aquifers, Sierra, Mohawk, and Hiflnbug Valleys Grovind Water Basins, Spring I960, is a generalized picture of the elevation of unconf ined or semiconfined ground water within the ground; water basins. Plate I9, Generalized Lines of Equal Elevation of Water in f Wells in Confined Aquifers, Sierra, Mohawk, and Humbiig Val leys Ground Water Basins, Spring I960, indicates the general elevation to i^iich confined ground water would rise in a well. Plate 20, Potential for Development of Grotmd Water, Sierra, Mohawk, and Humbug Valleys Ground Water Basins, presents the i preliminary evaluations of the potential for ground water development within these basins. Areas of hazard because of poor quality water are also indicatlld on Plate 20. Geologic History The Tertiary history of the Sierra, Mohawk, and Humbvig Valley aarea- is one of widespread volcanism. Up imtil the middle of the Pliocene epoch, the region was the site of outpourings of andesite, ash, tuff breccia, and bassilt. Associated with this volcanic activity was a period of extensive faulting which formed Sierra, Mohawk, and Hvunbug Valleys. After the valleys^ had formed, they became the location of lakes.. During the great ice ages of the Pleistocene epoch, glaciers majatled the Sierra Nevada. In moving dovn the movintain sides, they quarried and polished the "bedrock and deposited the rock debris as moraines. At the same time. Pleistocene lakes received sediments from the siirrounding mountains and outv£U5h debris trcm the melting glaciers. The lakes drained vestward into Jamison Creek and thence into Middle Fork Feather River. Eventually, a new- outlet to the IsJces was formed directly into Middle Fork Feather River. This new outlet was slowly eroded downward imtil both lakes were completely drained, leaving the valleys much as they are today. Water-Bearing Formations Table 13 briefly describes the geologic formations in Sierra, Mohawk, and Humbug VeuLleys. Of these, the principal water-bearing formations are Pleistocene lava flows, glacial outwash, lake and near-shore deposits, and Recent vaJ-ley sediments. Pleistocene Lava Flows . A mass of Pleistocene basalt is located south of the town of Vinton. Here, lava flowed out onto the valley floor and also covered the surrounding hills. After eruptions had ceased, the volcanic vent became plugged with lava. Subsequent erosion has stripped off large qioantities of material, exposing the plugged vent as a volcanic neck. This neck can be seen today and is located several miles south of Vinton. The Pleistocene basalt acts as a recharge area to ground water on the east side of Sierra Valley. A few wells intercept these lava flows where they have become buried in lake deposits. Because these lava flows are more permeable thein the enclosing lake deposits, the lavas yield large amounts of confined water to the wells. -ll+T- GEOLOGIC FORMATIONS IN SIERRA, MOHAWK, AND HUMBUG VALLEYS GEOLOGIC AGE SAND DEPOSITS STRATIGRAPHY APPROXIMATE THICKNESS IN FEET PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS BASIN DEPOSITS INTERMEDIATE ALLUVIUM ALLUVIAL FANS GLACIAL OUTWASH ,1_0^,0^ <^ i Loose, Mind-blown sand. Highly permeable but located above water table » hence con- tain little water. ftal i Unconaolidated sand and silt with lenses of clay and gravel. Moderate permeability. Yields moderate quantities of water to wells. £f: Unconsolidated gravel , aand, and silt with clay lenses. Iloderate to high' perateability. Yields large aiDOunts of wate to wells. May contain con- fined water. Moderate perneablllty. Yields moderate amounts of water to shallow wells. gs: Slightly consolidated, Dedded gravel, sand, and silt. Moderately permeable. Yields moderate quantities of water to wells. Contains confined pit subtly consolidated, bedded aand, silt, and dlato- maceous clay. Moderately to highly permeable. Principal acyilfer in valleys. Yields moderate to large quan- tities of water to wells. Contains confined water* ^. vb ! Jointed basalt flows con- aining sones of scoria. Moderate to high permeability. May yield large quantities of water to wells. May contain confined water. (jpo; Poorly consolidated mii- ture of gravel and silt. Moderate permeability. Hay locally yield moderate quan- tities of watei* to wells. Qpra ; Slightly consolidated mix ture of boulders, cobbles, sand, and rock flour. Low permeability. A few areas may yield small amounts of water. Tpl i Bedded, consolidated sand- stone and siltstone. Occurs only In Long Valley. Low to moderate permeability. May yield moderate quantitle of water to wells. May con- tain confined water. Tvrt Jointed, light gray phyollte. Essentially is^jermeable TsTp. Tsv: Flo .. p. fractured basalt. Plugs and flows of massive to platy andesite. Massive to bedded Budflows and tuffs. Permeability ranges from poor to moderate. Basalt may be permeable, but is mostly located above sone of satura- tion and hence is unimportant to ground water. Andesite and pyroclastio rocks are essentially impermeable. GRANITIC ROCKS * JKgr* -*■ -* JKgr i Hard, nonweathered grani- FTc rocks* Kssentially inqpenseable. p&ii Massive quartsite, slate, limestone, and mata-volcanio rocks. Essentially iiq)epneable« 148 Glacial Outvash. Glacial outvash deposits occijr mostly along the vest side of Mohawk Valley. The deposits are moderately permeahle and may yield moderate amoimts of ground vater to wells.. There are several permeable zones in the glacial outwash deposits which yield notable quantities of ground water to springs. LaJte and Near-Shore Deposits. The central portions of Sierra, Mohawk, and Himbvig Valleys are largely made up of lake and near-shore deposits which are overlain by Recent sediments. The lake and near-shore deposits are trp to 2,000 feet thick and provide most of the ground water developed in the valleys. The lake deposits range in composition from permeable sand to nearly impermeable clay. The sand beds usually yield large quantities of confined ground water to wells. Tb.e near-shore deposits are composed of moderately permeable sand and gravel and \rfiere saturated usually yield moderate amounts of ground water to wells. Recent Valley Sediments. The Recent valley sediments incliide alluvial fans. Intermediate alluvium, and basin deposits. Although Recent sand and silt deposits and Pleistocene to Recent terraces are actiially a part of the valley sediments, they are not discussed becavise of their limited areal extent and limited use as a source of grovmd water. Alluvial fans surround most of Sierra Valley. The fans may be sis much as 200 feet thick and are a major source of ground water in the valley. Where adeqviately recharged they should be able to provide large qioantities of both confined and \anconfined ground water to wells. There are a few aresis of intermediate alluvium in Sierra, Mohawk, and Humbug Valleys. Ihese deposits are estimated to be not over 50 feet thick and are vuaderlain by lake deposits. The intermediate alluvium provides fair to good quantities of ground water to shallow wells. Basin deposits occur only in the central, poorly drained portion of Sierra Valley. These deposits are estimated to have a thickness of about 50 feet and are underlain by lake deposits. The basin deposits are of low permeability and generally yield only small amounts of water to shallow wells; however, the presence of alkali may adversely affect the qtiELLity of the water. Influence of Geologic Structure on Ground Water The moiintains surrounding Sierra, Mohawk, and Humbug Valleys contain numerous faults, many of which are shown on Plate 1?. A recent geophysical survey of Sierra Valley by the Department of Water Resources indicated that faults have broken the bedrock beneath the valley floor into numerous tilted fault blocks. This has resiilted in a bedrock surfaxje viilcb. ranges from a few hundred feet to about 2,000 feet below the floor of the valley. An idea of the geologic structure of Sierra Valley can be seen in generalized geologic 1 P 12 sections A-A-^-A and B-B -B , presented on Figures 17 and I8, respectively. These sections show the probable structviral conditions to a depth of about 2,500 feet below the floor of the valley, largely from interpretation of the geophysical survey by the department. The survey indicates that the bedrock beneath the floor of Sierra Valley has been broken into several high and low areas, bounded by the faults which enter the valley from the north and south. The thickness of sediments overlying the high areas is about 8OO to 1,000 feet while that overlying the ^ low areas is on the order of 2,000 feet. ' The origin and history of the low volcanic hills knows as The ^ Mounds are some'tdaat uncertain. These hills apparently do not have a bedrock | connection and thus may be resting on lake sediments, as shown on Figure I8. | Hiey apparently were formed by a tongue-like mass of andesite lava which flow# OTit Into the valley and then became almost completely buried by later .< -150- ] .\^r.v \ 90^'omqBiHSn <^ ^^\\\\->i " NOiNIA s liHr'for. J ff^ /OMi/BlH HOIS € 1 ♦ Hi/dM ^'' ll liv & 1 1 I'. ; o — * ! V 1 \ M c 5 a. >- o ID o 1 1 - * UJ : \\\\l^V^ _J A f ll'lili?'"^ _l 1 1 1 ' M . • £ \\\ ' * < VM/^ JtlltOtJ IIJOJ tlppllH S| 1 u ' + s > / 1 1 /,. 2 / il ' 1 '' ** i / 1 ' ' I 1 ' ' '' * "^ "*■ < / - E z q: 11- 5 = |i ( 1 ' I 1 1* * V ♦ + + z (£ 1' Jl 1 ' \ * ' * ' ' - J , nnVj i3n»A iizziao^ UJ <|_ Q ^-^ '1 II 1 ' * * * * — *i^rf^ c^ ^ M 1*" * * <0 1^ ?i !i,i !■■•■.■ aOl ON poou Xiunoj \ 1 1 i fi^: « ^< 1 1 • ' .s i' ' ■; /- «* III '/"/' •• 1 l' 1 1 ' ' * ^ * \\\'\< 1 ,1,'^ ' ' ^ all 1 , ii 1 '! ' ' . 4. — ♦ • r» iii' Q !=--|'|i = |-'i 14 H'/' . - m tv j; nn»j soNitidS ioh fiO/ o/V /««>i/ //1//I05 S. m^ mf\\ '.?'»*• ♦ ^ '^ /"^^'K- *♦ = •r ^/ o • «^ * • jl^ltl;-.;: 5 jl <^^^s^j «l i l|D>d H(Jno«i|3ag "jWjITOWlti^'l'llLwIlt '1/'' • a\ 1 imvhow § j/o0/..^ /C" ir - ^ *»»^J V/w? jC^^' ^y \~ '^ „ /^"'l 1 1 1 1 1 i 1 1 1 1 1 1 O O o o o o O O o o o o o o o o o o h- «) lO * K> CJ wniva s 9sn laaj ni NoiivAana c 15^^ Very little is knovm of the structiire of Hxanbug Valley. It appears to be faulted in a similar manner eis Mohawk Valley. The depth to bedrock in Hmnb-ug Valley is probably not over 5OO feet. Recharge and Movement of Ground Water The recharge and movement of ground water were evaluated for only Sierra and Mohawk Valley ground water basins. Ins\ifficient data were available to make such an evalvjation for Humbug Valley. Sierra Valley Ground Water Basin . Most of the upland recharge areas in Sierra Valley grovind watei bsisin, shown on Plates I8 and I9, are composed of permeable materials occurring along the upper portions of the alluvial feuas which border the valley. Recharge to ground water is primarily by way of infiltration of surface water from the streams which drain the mountains and flow across these fans. A minor amount of recharge also may be derived from some of the Sierran volcanic rocks which surround much of the valley. Most of these rocks appear to be of fairly low permeability and thus only small quantities of recharge could be derived from them. Mean seasonal precipitation varies from about 12 inches on the valley floor to more than kO inches on the upper portion of the drainage 8Lrea. The maximimi and minimum seasonal larecipitation at Sierraville was respectively 14-3.80 inches during the 1912-13 season and 8.23 inches during the 1923-24 season. ISae mean seasonal precipitation is 2lt-.23 inches. At Portola, the mean seasonal precipitation is iS.lij- inches. The TnavinniTn and minimvan recorded seasonal values are 36. 10 inches during the I95I-52 season and 6.I7 inches during the 1923-214- season, respectivfely. -155- An essentially unconfined ground water body imderlies the valley floor sj-ea of Sierra Valley at shallow depths. Lines of eqiml elevation of this ground water body are shown on Plate l8. Wells which intercept this body are \as\xally less than 100 feet in depth aJid are used primarily for domestic ptirposes. Water svirface levels from wells supplied by this near- surface source indicate that the direction of movement of this ground wate body is similar to the general direction of svurface water movement in the veuLley. A large qiiantity of ground water which underlies the floor of Sierra Valley is contained within numerous confined aquifers. Wells which intercept these aquifers usiially flow. Depths of flowing wells range from about 100 feet along the margin of the valley floor to a^ much as 1,000 feet in the central part of the valley. Plate 19 shows lines of equal elevation of this confined ground water body. The piezometric stirface of this ground water body slopes generally toward the northwest. Ihe portion of the valley floor within ^ich wells flow is also shown on Plate I9. This particular area may extend to the base of the foothills in the vicinity of Sierraville. The ground water moxmd in the vicinity of Marble Hot Springs is apparently due to thermal waters which rise along fracture zones of the Hot Spring fault and the intersecting fault to the east. The area of influence of Marble Hot Springs is believed to be fairly limited. Water from wells in the vicinity of the hot springs ranges in temperature xxp to 206° Fahrenheit and is generally of poor quality. Undoubtedly, some of the thermal waters commingle with ground water from confined aquifers in the vicinity of the fault zones. To reiterate, at least three different types of ground water may be intercepted by wells drilled in Sierra Veilley, a near-surface vmcon-' i fined body, a deeper confined body, and deep seated thermal waters in the vicinity of faulting. -156- Mohavk Valley Grovind Water Basin. Despite the fact that the upland recharge sirea for Mohawk Valley groimd vater basin Is considerably greater than that for Sierra Valley, the iipland deposits are at best only moderately permeable. Pyroclastic rocks which adjoin the valley on the northeast are essentially impermeable except aiong bedding planes, joints, and fractures. Moraihal deposits alonig the southwest border have a hi^ clay content and sire only locally permeable. Mean seasonal precipitation varies from about 28 inches on the valley floor to over 50 inches on some of the higher i)eaks to the southwest of the valley. There are no precipitation stations with long term records in Mohawk Valley. Ground water data are extremely scarce in Mohawk Valley, hence the lines of equal elevation shown on Plate l8 are beused primarily on topography, the location and flow of springs, and other observable factors. Groimd water is believed to move toward Siilphior Creek and Middle Fork Feather River from the northeastern and southwestern sides of the valley. Both unconfined and confined ground water bodies exist in the valley but insufficient data are available to define them at this time. Most of the ground water level measurements in wells probably reflect a combination of both confined and unconfined ground water. The many small springs which are found in and around Mohawk Valley are due princlpsilly to local permeable zones in the morainal deposits. The warm sulphur springs at McLear's Resort are apparently due to water rising eilong a faiilt. Present Use of Ground Water The majority of the k2,000 acres of irrigated lands within Sierra Valley are situated adjacent to the surfsuie streams. The flows from these -157- streams are primarily from snowmelt and are insufficient to irrigate the 106,000 acres of irrigable lands within the floor of Sierra Valley. Supple- mental irrigation water is us\aally req\iired after the first of June within the northern portion of the valley floor. The southeastern portion and western portions of the vaJLley floor usually need supplemental water after the middle of June and the first of July, respectively. Recently constructed Frenchman Dam and Fteservoir on Little Last Chance Creek will provide addi- tional water supplies to the northeastern portion of the valley floor. The yield from existing and potential sxirface water develojHnents is insuffi- cient to irrigate all of the irrigable lands within the valley floor. The vise of ground water for irrigation purposes has increased in recent years, although only 13 of the k03 wells inventoried during, the period of investigation were used for irrigation pixrposes, while the majority were used for domestic and stockwater purposes. Two wells near Loyalton sejrved as a partial mimicipal supply for this community. The reported groimd water yields of the irrigation wells inventoried range from about 60O to 1,800 gallons per minute. The maximum reported non- pumped flowing well yield is 300 gallons per minute. The portion of Mohawk Valley ground water basin classified as valley floor land encompasses aboixt 10,000 acres, over half of which is irrigable. About 2,000 acres are presently irrigated and the water supply is obtained by diversions from streams within the area. Only six wells have been located in Mohawk Valley and none of them is classified as an irrigation well. ground Water Developnent Potential All fovac zones of potential for development of ground water are present in Sierra Valley. Only three of the zones are present in Nfohawk -158- Valley. Humbug Valley ground water basin was not evaluated. The area of the valley floors in each classification is shown on Plate 20. The general condi- tions which presently govern the potential for development of groimd water within each zone found in the two valleys are discussed below. Sierra Valley "A" Zone. "A" Zone areas, located near Loyalton and Sierraville, are apparently underlain by thick alluvial fan and near-shore deposits. Adequate recharge of ground water within these areas is by way of infiltration of surface water into the relatively extensive alluvial fan deposits located south of the two areas. Sierra Valley "B" Zone. The "B" Zone areas in Sierra Valley are imderlain by near-shore, alluvial fan, and other sediments which are similar to those in the "A" Zone areas, but are either less permeable, thinner, or possess less ground water recharge potential. As a result, the groimd water development potential of the "B" Zone areas is less than that of the "A" Zone areas. Part of the northern portion of the eastern "B" Zone area is under- lain by basalt flows interbedded with lake deposits. If these basalt flows are adequately recharged and sufficiently permeable, a relatively higher yield can be expected from this portion of the eastern "B" Zone area. Sierra Valley "C" Zone. Within "C" Zone areas the probability of constructing high yield irrigation wells does not appear favorable, but well yields should generally be sufficient for domestic and stock-watering uses. The valley fill sediments near the edge of the valley floor are composed essentially of the thinner portions of alluvial fans overlain by a relatively thin mantle of intermediate alluvium and basin deposits. Within the west central portion of the valley, the valley fill sediments consist primarily of -159- leLke deposits overlain by a thin mantle of basin deposits. The relatively shallow thickness of the sedimentary materials near the edge of the valley floor, and the relatively low permability of the sedimentary materials within the west central portion of the valley, restrict the ground water development potential of these areas. The "C" Zone area southwest of Vinton may possess a higher developnent potential than indicated if underlying basalt flows prove to be reliable aquifers. Sierra Valley "D" Zone. "D" Zone areas are located adjacent to intpermeable rock or within areas possessing particularly low recharge poten- tial. The sedimentary materials within these zones are permeable, but their thinness and low recharge limit well yields to relatively small quantities. General. High yielding irrigation wells may be located within two portions of the floor of Sierra Valley. One such area is situated near the sovrthern end of the Sierraville arm of the valley floor, and the other is northwesterly from Loyalton. Underlying this latter area are buried basalt flows which may yield large quantities of ground water to wells approximately 1,000 feet deep. Below the point where the major streams enter the valley floor, there are Eireas within which irrigation wells of moderate yield may be located. Most of the remainder of the valley floor area does not appeetr to be sxiitable for irrigation well development. Wells for domestic and stock-l watering vtses may be located almost anywhere on the valley floor except within: areas underlain at shallow depths by impermeable rock. Mohawk Valley "B" Zone. The area of Mohawk Valley which is classifi as "B" Zone is located southeasterly of Graeagle. The sands and gravels vhiob underlie this area are i)ermeable and are recharged from Middle Fork Feather River and other streams. Wells capable of producing supplies of groirnd water -160- sufficient for irrigation ptirpcses are possible, providing proper veil constriic- tlon and competent developoent practices are followed. Mohawk Veilley "C" Zone « Most of Mohavk Valley is classified as a "C" Zone area. Wells located here have only a fair development potential tecaiise of the fairly low permeability of the vmderlying materials. Occasional irrigation yields may be obtained, but should not be expected, Mohawk VsOley "D" Zone . Materials vmderlying the "D" Zone areas range from permeable alluvial fan deposits throvigh poorly permeable glacial ovctwash deposits. "D" Zone areas In Mohawk Valley are so classified princi- pally because the water-bearing materials are thin. Wells in "D" Zone areas would yield little, if any, ground water. Ground Water Storage Capacity The ground water atorage capacity of Sierra Valley has been estimated to be about 7*500,000 acre -feet for the depth Interval between Sero and 1,000 feet. Storage capacity for Mohawk Valley has been estimated to be about 90,000 acre -feet for the depth interval zero to 200 feet, and that for Humbug Valley has been estimated to be about 76,000 acre -feet for the depth interval zero to 100 feet. How much of the ground water in storage is useable or how much useable storage exists below the depth inteirvals cited is not known. It Is reasonable to assume "bhat a slgnlflescErt: asBtmat of ground, water could be developed. Quality of Ground Water Grovind waters In Sierra Val ley display a wide range in mineral quality. The grotmd waters in this valley south of Highway ^OA and north and west of Loyalton are usually poor In quality. Within this area there are hot springs and thermal artesian wells associated with faults as previously -161- described. The poorest of the thermal waters are mostly sodium chloride in character and are considered hazardous for most "beneficial uses, while the remainder of the waters are mostly sodiian bicarbonate. Ground waters else- where in the valley are of good quality axid suitable for most beneficial uses. No particular cation is dominant in these waters but bicarbonate is usually the predominant anion. The ground waters in Mohawk Valley are generally of excellent mineral qiiality. They range in character from calcium-magnesium bicarbonate to sodium biceirbonate and are siiitable for most beneficial uses. Water Quality Problems Ihe hot springs and several of the thermal artesian wells in Sierra >. Valley yield waters which are considered hazardo\is dvie to high electrical conductivity and excessive concentrations of boron, chloride, fluoride, iron, and sodium. Several wells also yield water containing significant concentratici! of eirsenic and manganese. All of these waters, which are lonsuitable for most beneficial uses, are located within the hazard area shown on Plate 20. Water qiiality data indicate that mineralized waters have migrated from the hot springs and thermal artesian wells and impaired adjacent ground water within this area. AlthoiJgh waters of iisable quality can be foxmd within this sirea, more often waters of hazardous quality will be found. Excessive boron has been found in the waters throtighout this entire area. Scattered throi;ighout Sierra Valley are a few other wells yielding groimd waters which contain excessive concentrations of one or more of the following constituents: fluoride, iron, manganese, and nitrate. However, these appeeir to be only localized conditions of impairment. Conclusion Within Sierra Valley, moderate to high yielding irrigation wells can apparently be developed within about one qiiarter of the valley floor area* -162- Within a portion of this airea, veils are subject to pumping water >diich is of poor quality for irrigation. Well yields vithin the remaining three- quarters of the valley floor ax>ea are restricted principally by low aquifer permeability. One possible exception is the buried basalt flows along a portion of the eastern side of the valley floor. These flows may prove to be reliable aquifers. Upland areas of recharge are very limited surrovuading Sierra Valley. Water quality will also limit ground water developnent within the northwestern portion of the valley floor area. If a high level of ground water developnent is achieved along the eastern side of the valley floor, the area of water quality hazard probably will migrate eastward. The ground water development potential of ^fohawk Valley for irriga- tion purposes is generally limited by the low permeability of materials tmder- lying much of the valley floor. Generally, the quality of grovmd. water within the Itohawk Valley ground water basin is excellent. Except for the water quality hazard within Sierra Valley, ground water development potential for domestic and stockwatering uses appears good throughout both Sierra and Mohawk Valleys. It is concluded that the basic data collection activities of the Department of Water Resources should be continued in order to facilitate futxure quantitative and qualitative analyses of the grovuid water baain. Encouragement should be offered to local agencies in their efforts to develop the groxind water potential in the manner best suited to local jjroblems asid in accordance with information in this biiUetin. -163- Surprise Valley Ground Water Basin Surprise Valley ground water "basin is located in eastern Modoc County and northeastern Lassen County, California, and western Washoe County, Nevada. The valley is roughly 50 miles long and 12 miles wide. Its floor lies at an elevation of about 'l-,500 feet. The valley is bounded on the west by the Warner Mountains, which rise to an elevation of 9,883 feet at Esigle Peak. To the east, in Nevada, is the Hays Ceuiyon Range, having a maximum elevation of over 7,000 feet. Surprise Valley is one of internal drainage as it has no outlet. The valley contains three lakes. Upper Alkali Lake, Middle Alkali Lake, and Lower Alkali Lake. The lakes are shallow, extremely saline, and are usually diy dxiring the s\immer months. Most of the streams draining into Siirprise Valley originate along the eastern slopes of the Warner Mountains and discharge into the three lakes. Surface exposures of the various geologic formations of the Surprise Valley area are shown on Plate 21, Areal Geology, Surprise Valley Ground Water Basin. Plate 22, Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Siorprise Valley Groxxnd Water Basin, Spring I96O, is a generalized pictiire of the elevation of ground water within the gro\uid water basin. Plate 23, Potential for Development of Ground Water, Surprise Veilley Gro\ind Water Basin, presents the preliminary evalimtions of the potential for ground water development within this basin. Areas of hazard because of poor quality water are also indicated on Plate 23. Geologic History During the early part of the Tertiary period, the area which now includes Surprise Valley was a leuid of low, rolling hills ajid extensive lava plains. Late Miocene faiiltlng broke the old land surface ajid formed aji -165- entirely new landscape consisting of faiolt block mo\intains and long, narrow valleys, one of which is now Sixrprise Valley. During the Pleistocene epoch, there was a decrease in the tempera- ture and a corresponding increase in the precipitation. Because the valley had no outlet, a lake formed. This lake, called Lake Surprise, slowly grew ' in size until by about 70,000 years ago, it had attained a depth of about 500 feet. The lake persisted for about 15,000 years until a decrease in precipitation and a general warming of the region caused the lake nearly to dry up. Then there was reversal of the warming trend, colder and wetter years again predominated, and once more the lake filled the valley. The second lake lasted luitil about 20,000 years ago. The many old beaches and terraces seen along the sides of the valley today near elevation 5,000 feet offer mute evidence of the size and depth of this once great lake. During niuch of the time that Lake Surprise was present, glaciers mantled the Warner Mountains. These ice masses carved great cirques into the mountain crest. The end of the glacial period was marked by a gradixal increase of temperatures and a decrease in precipitation. The glaciers were the first to disappear. Then the lake itself slowly began to shrink in size and depth. Today, the three alkali lakes remain as mere remnants of ancient Lake Surprise. Water-Bearing Formations Table l^i- briefly describes the geologic formations in Surprise Valley. Of these, the principal water-bearing foimations are near-shore deposits and Recent valley sediments. Near- Shore Deposits . Near- shore deposits occur as highly permeable terraces, beaches, spits, and deltas formed in ancient Lake Surprise. Where .166- GEOLOGIC FORMATIONS IN SURPRISE VALLEY EOLOGlC AGE PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS Highly permeable. Located above water table; acta to recharge underlying materials Yields little water. fta ; Unconsolidated, wind-blown sand and silt; alkali often present. Permeable but contains little water due to being above water table. 1: Unconsolidated to seml- consolldated clay, organic muck, and fine sand. Alkali and salt present. Generally nearly Impermeable. Contains small amounts of co fined water in stringers of fine sand. (jb: Unconsolidated deposits of sand, silt, clay, and organic muck. Permeability generally low, but locally may be sufficiently permeable to yield small amounts of water to shallow Qal ! Unconsolidated sand and silt with some gravel and clay Moderately permeable; yields moderate amounts of water to wells. y : Unconsolidated to partly consolidated, poorly stratified gravel, sand, and silt with clay lenses. Generally highly permeable. Important west side aquifer; yields abundant supplies of free and confined water. ftps : Poorly consolidated gravel, sand, and silt deposited as deltas and terraces. Moderate to high permeability. Yields large quantities of free and confined water. (jpmt Unconsolidated mixture of toulders, gravel* silt, clay, and rock flour. Low permeability. Hay yield minor amounts of water tc springs. bas Permeability ranges from low to high. Acts to recharge sedi- ments in Surprise Valley. May yield moderate amounts of water to wells. Tvr : Fractured flows and shallo Intrusivea of pale-colored rhy elite. Essentially impermeable. Jointed vesl- wa, flows of platy andeslte, and beds of rhyollte tuff. Permeability ranges from poor to moderate. Basalt acts as re- charge area. May locally yield moderate amounts of water. to wells. Andeslte and pyroclastlc rocks are essen- tially inpermeable. Moderate permeability. Certain beds may yield moderate amounts of water to wells. Tme t Massive tuff-breccias a tuffs. Includes flows of Miocene basalt and andeslte Also includes some tuffaceo sediments correlative with Forty-nine Camp formation. Essentially impermeable. T^dc ! Nasalve, consolidated con ' glomerate with beds of shale, mudflows, and tuff. Essentially impermeable these deposits are exposed on the groiind surface, they are Important as re- charge areas. Where below ground and saturated, they are Important water- bearing materials as they are capable of yielding large amounts of ground water to wells. Recent Valley Sediments . Recent valley sediments include alluvia fajis, intermediate alluvium, and basin deposits. Although the lake deposits in the three alkali lakes' are actually a part of the Recent valley sediments, they are not discussed below because they yield only small amounts of ground water. Alluvial fans in Surprise Valley may be as much as 1,000 feet in thickness and contain the principal aquifers in the valley. Ihese aquifers are capable of yielding large quantities of confined and semiconfined groxmd water to wells. The alluvial fans also are important as recharge areas, particularly the highly permeable upper portions of fajis along the west side of S\irprise Valley. M Intermediate alluvivun occirrs between the alluvial fans ajid the basli deposits. These intermediate alluvial deposits are estimated to be not over .50 feet in thickness. They are underlain in some places by the valleyward extensions of the alluvial fan deposits, and in other places by laJse deposits In general, the intermediate alluvivun is only moderately permeable, and will J yield moderate amoxints of ground water to shallow wells. , n Basin deposits occur in the- flat portion of the valley along the western edges of the alkali lakes. These deposits are estimated to be not over 50 feet thick. In some places they are underlain by the valleyward extension of alluvial fan deposits, and elsewhere by lake deposits. The permeability of the basin deposits is generally low, but locally they may sxifficiently permeable to yield small amovints of water to shallow wells. -168- Influence of Geologic Structiire on Ground Water Surprise Valley is an elongated, faulted depression bounded "by up- lifted, tilted mountain ranges. The valley and its surrounding mountains are crossed by numerous faults, many of which are shovn on Plate 21. Many of these faults are clearly visible in the upland regions, but faults passing beneath the floor of the valley are hidden from view. In order to determine the location of these hidden faults, it was necessary to make a geophysical survey of the valley floor area. The survey showed that the bedrock beneath the valley floor has been broken into many tilted fault blocks, resulting in a bedrock siirface which ranges from a few hundred feet to over 5,000 feet below the floor of the valley. An idea of the geologic structure of the valley can be had by referring to generalized geologic sections A-A and B-B"*" presented on Figtires 20 and 21, respectively. These sections show the probable structural conditions to a depth of about 5,000 feet below the floor of the valley. Substirface features shown on these figures, as well as locations of many faults shown on Plate 21, are from interpretation of data from the geo- physical survey. The most prominent structural feature in Surprise Valley is the Surprise Valley fault. This fault extends from near Fort Bidwell southerly along the base of the Warner Mountains fco Duck Flat, in Nevada, a distance of about 60 miles. Movement along this fault probably began about five million years ago. Since that time, there has been over 5,000 feet of vertical dis- placement, resulting in the creation of a rugged fault scarp along the eastern front of the Warner Moimtains. An idea of the magnitude of vertical displace- ment along this fault can be had by noting that the Miocene lava flows exposed at ah elevation of about h,3C0 feet north of Cedar Plunge are probably the same flows which cap Eagle Peak at an elevation of 9,883 feet. -169- - 3Nn 3i»IS »0 UJ to E CL q: =) CO llrffe rll nnw Alio 3»vn 0/ T^/'-V nnW A1I3 3XV / ON ovoy AiNnoo- 1° v^ ~^ "=:'^nvd xjinmisiadans ^ ^>.x^ s. ^ -^V^N WfliVa S£)Sn i33d NI N0I1VA313 SURPRISE VALLEY UIDDL£ ALKALI LAKE ■smi ^?>».- ^^ y^ '^.^-^ ^ -y '^'' cKZX^ LENGTH IN MILES Sm Piatt 21 fQf locotion of i Figure 21. GENERALIZED GEOLOGIC SECTION B-B' SURPRISE VALLEY GROUND WATER BASIN Majiy faijlts in Stirprise Valley affect ground water movement and quality. Some of them act as barriers to ground water movement either by offsetting permeable beds against those of lower permeability or by the creation of an impermeable gouge zone. Faults of this type may be partly resjKjnsible for confinement of ground water. Many of the faxolts indicated by dotted lines on Plate 21 are probably in this category. Other faults, notably those crossing areas of basalt, tend to create a permeable, govige-free zone. These zones serve as paths for the downward and lateral percolation of subsurface water and thus allow water to move from areas of recharge to the deeper sedi- ments in the valley. Some of the faults which pass beneath the valley floor have broken, permeable zones which go deep into the bedrock and serve as paths for the upward migration of superheated steam and water. Hot springs, such as occur at Cedar Pl\inge, Old Leonard Baths, and Menlo Baths, are the result . -171- Recharge and Movement of Ground Water In S\irprise VsLLley ground water basin, ground water moves from the mountains toward the lakes which occupy the central portion of the valley floor. Recharge to groiond water on the west side of the valley is from infiltration of surface water into the apexes of the alluviSLL fans located below the mouths of canyons along the base of the Warner Mountains. In the extreme northern portion of the valley floor, siirface water from the north infiltrates the coarse stream deposits and recharges the \inderlying ground water bodies. As these recharge areas are all within the valley floor area, no true upland recharge areas exist along the western emd northern sides of Surprise Valley. There are extensive upland recharge areas along the eastern side of the valley, as shown on Plate 22. Ihese areas are composed of sediments of the Forty-nine Camp formation and the overlying Miocene basalt. Topographic and geologic conditions appear favorable for some subsurface inflow of grovind water into Surprise Valley from Long Valley, Nevada. Farther south, sub- surface inflow of groimd water to Surprise Valley apparently comes from the northern portion of Duck Flat, Nevada. Along the southwestern margin of: the valley, outcrops of ELio- Pleistocene basalt probably afford some oppor- ■] tunity for recharge to the ground water bodies within this portion of the valley. The Warner Mountains act as a barrier to the general northeasterlj direction of movement of most major storms in this part of California. Moist air masses tend to drop precipitation on the mountain range, but not in Surpidl Valley on the lee side of the range. The Hays Canyon Range produces anotherj storm barrier action, but the magnitude of precipitation produced is less than that effected by the Warner Mountains. This unequal precipitation -172- I)attern caused by the two moimtain ranges and other upland areas siirrounding Surprise Valley has resulted in unequal distribution of available irrigation water and related agricultursil development. Mean seasonal precipitation varies from l6 to 10 Inches from the north to the south edge of the valley floor and increases generally with Increased elevation on the east side of the Warner Moiontains to in excess of 32 inches on the higher peaks. On the valley floor, in the region of Lower Alkali Lake, the mean seasonal precipitation ranges from less than 6 Inches along the east edge of the leike bed, to about 10 inches at the base of the Warner Mountains, and to about 8 inches at the base of the Hays Canyon Rajige. The precipitation on the valley floor generally Increases in the northerly direction. On the Upper Alkali Lake portion of the valley floor, the minimum mean seasonal precipitation of less than 10 inches occurs along the east edge of the lake bed. Near the base of the Warner Mountains, the precipita- tion is l6 inches, while near the California-Nevada state line, it is about 12 inches. Published records from precipitation stations located at Fort Bldwell and Cedarvllle date from the present back to 1866 and 189^^, -respectively. The recorded maximum and minimum seasonal precipitation at Fort Bldwell is 3^4-. 02 inches during the I876-77 season and 7.69 Inches during the 1932-33 season, respectively. The similar extreme values at the Cedarvllle station are 21.17 inches during the 1937-38 season and "J .Ok Inches during the 1932-33 season, respectively. Most of the precipitation on the upland areas surrounding Surprise Valley Is in the form of snow. Snow siirveys in this area have been conducted annually since 1930. The water content of the snow at the Cedar Pass course averages I6.9 inches while the maximum and minimum values on April 1, are 33.6 Inches during 1952 and 1.0 inches during 193^. -173- The generalized lines of equal elevation of water in veils shown on Plate 22 were used to determine the general direction of movement of groiind water within the major portion of the Surprise Valley ground water basin. Within the eastern portions of the basin for which lines of equal elevation are not shown, the general direction of ground water movement is probably- westerly from the foothills toward the lakes. The lakeward direction of ground water movement results in the division of Surprise Valley ground water basin into three ground water sub- basins. These subbasins are named with respect to the lake in which the movement of ground water terminates, namely. Upper Alakli Lake subbasin. Middle Alkali Lake subbasin, and Lower Alakli Lake subbasin. The ground | water divides located between each of the three lakes are the resiilt of the lakeward movement of ground water. Because a groiind water divide is subject to change in location, the sixrface water drainage divide between each of the lakes is considered as the subbasin boundary. Plate 22 shows these subbasins and their respective boundaries. Lines of equal elevation of water in wells are shown on Plate 22. One outstanding ground water characteristic of the west side of Surprise Valley is the extensive portion of this area within which the piezometric siirface is above ground surface. The piezometric surface probably represen' a composite of numerous, partially Interconnected, confined ground water bodl Each body is more or less restricted to the alluvial fan ajid/or associated materials within which recharge takes place. Within any one alluvial fan, or fan complex, there is generally more than one confined ground water body. But primarily because the recharge area for each ground water body is more or less at the same elevation, the piezometric surface of each body approximates a similar shape and elevation. Within the western portion of the valley. -17^- •4j . ^ there are known excepfcions to the above generalization concerning multiple aquifers. These exceptions, particijlarly in the area west of The Islemd in Middle Alkali Leike, are disclosed by the elevation of the piezoraetric surface at a few wells being considerably different from the piezometric surface shown on Plate 22. An essentially imconfined, near-surface ground water body is present throughout most of the valley floor area. Along the north, west, and south sides of the valley floor, the configuration of the water table approximates that of the piezometric surface shown on Elate 22, but is at an elevation varying from ground s\irface to 50 or more feet below gro\Hid surface. Within this portion of the valley, the pimipage from this near-surface ground water body is, and will probably continue to be, relatively minor as compared to pumpage from the deeper, confined ground water bodies. Along the east side of the valley, ground water elevations are available only in the vicinity of Cedar ELiinge. Here, near-surface ground water is presently the principal groTind water body utilized. Its use in the futtire is expected to diminish in favor of deeper, confined ground water bodies. The generalized lines of equal elevation of both the near- surface and a deeper, confined ground water body in the vicinity of Cedar Plunge are shown on Plate 22. Within this area, the upper, essentially unconfined, ground water body is intercepted by wells of 60 feet or less in depth. Deeper wells, usually in excess of 90 feet, intercept the underlying confined ground water body. The primary recharge to ground water within both of these bodies is apparently from the alluvial fans of Sand Creek and Forty- nine Creek. The direction of movement f! of both ground water bodies is southwesterly toward Middle Alkali Lake. c Heated, mineralized ground water rises along certain faults in pj; Surprise Valley. In some areas, this thermal water appears at the ground -175- surface at hot springs, and in other areas is tapped by hot water wells. The probable areas where this thermal water may adversely affect the quality of groixnd water is discussed in the water quality portion of this report. Present Use Approximately 33,000 acres of the 223,000 acres of valley floor lands in the California portion of the Surprise Valley ground water basin are irrigated at the present time. Only a very small percentage of these irrigated lands are located on the east side of the valley floor. Both poor soil conditions and insufficient siirface water have limited agricultural development on this side of the valley floor. The level of agricultural development in the California portion of the valley floor lands is limited primarily by the availability of surface water supply. The present supply is derived essentially from the diversion of nonregulated streamflow. Ground water development for irrigation use has increased substantially dxiring recent years. Of the 522 wells located within the California portion of the basin, 58 wells are used for irrigation purposes Most of the non- irrigation wells are either flowing stockwatering wells or domestic wells. The yield of ground water from irrigation wells generally ranges from 300 to 2,800 gallons per minute. The highest reported discharge from a nonpumping flowing well is 1,200 gallons per minute. Groimd Water Development Potential Within the California portion of the valley floor area of Siirprise Valley, all four zones of potential for development of ground water are present. The area of the valley floor in each classification is shown on Plate 23. The general conditions which presently govern the potential for development of gro\ind water within each zone found in this basin are discussec .176- below. Available information is insiifficient to determine the classification of lands along the east side of the valley, but the known factors pertaining to development of ground water along this side of the vsilley are presented following the discussion of the four zones. "A" Zone . The "A" Zone areas in Surprise Valley are underlain by fairly permeable materials that receive adequate recharge. The "A" Zone areas south of and near Cedarville contain near-shore deposits overlain by alluvial fans. Large queintities of surface water from streams draining the Warner Mountains infiltrates the alluvial fans at the mouths of the canyons and percolates into the near-shore deposits. The "A" Zone area at the north end of the valley is underlain by near-shore and alluvial fan materials along its western side, intermediate alluviiom in its middle portion, and Forty-nine Camp formation along its eastern side. The western side of this zone possesses a good recharge oppor- tiinity from water infiltrating channel materials of Bidwell Creek and Mill Creek. The recharge opportunity to ground water in the central and eastern portions of this zone appears adequate for additional ground water develop- ment, but not to the extent of the other "A" Zone areas within the valley. "B" Zone . Much of the irrigable lands along the west side of Surprise Valley are classified as "B" Zone. These "B" Zone areas are under- lain by near- shore, alluvial fan, and other sediments which are somewhat thinner and/ or less permeable thaji similar materials underlying the "A" Zone areas. The recharge opportunity of the "B" Zone areas is generally somewhat less than for the "A" Zone areas. The "B" Zone areas in the north and south portions of the valley are considered to have the lowest development potential of the lands classi- fied as "B" Zone. This is based on the fact that the overall permeability of -177- the underlying intermediate alluvium and basin deposits is generally less than that of the adjacent, more permeable alluvial fan and near-shore deposits. "C" Zone . The alluvial fan, intermediate alluvium, and near-shore deposits located in "C" Zone areas near the margin of the valley floor are quite thin. Ground water bodies in these areas are not sufficiently thick for development of high yielding irrigation wells, but well yields should be sufficient for domestic and stockwatering uses. "D" Zone . The "D" Zone areas are of two basic types. One type, located adjacent to the lakes, is composed of basin deposits underlain at depths of less than 50 feet by relatively impermeable lake deposits. Any water in wells located in these "D" Zone areas would be derived primarily from surficial materials and/ or from the waters of the adjacent lake. The other type of "D" Zone area is located adjacent to outcrops of impermeable rock. Surface materials here may be quite permeable, but becatise they are xmderlain at shallow depths by impermeable rock, wells in these "D" Zone areas would yield little, if any, ground water. East Side Valley Lands . At the present time, ground water devel- opment along the east side of Surprise Valley is relatively minor. However, there appears to be a relatively good potential for further development of grovmd water in areas underlain by the Forty-nine Camp formation and Miocene basalt. The subsurface extent of the Forty-nine Camp formation is not known, "^ but it is suspected to underlie much of the east side of the valley north of Old Leonard Baths. Available precipitation will limit recharge to ground ' water in this area and thus preclude any extensive development of sustained yield from wells. General. Insufficient data are available to formulate an opinion the ground water development potential along the east side of the floor of Surprise Valley. Throughout the remainder of the California portion of the -178- I valley floor^ except for areas occupied by the lake beds, the ground vater development potential, in general, is in excess of the present use of ground water. The extensive alluvial fans along the west side of the valley floor, and the Recent sediments underlying the northern and southern ends of the valley floor are fairly permeable and are sufficiently recharged to permit an increased amount of ground water development. Within specific areas, the recharge is excellent and the development potential is considered sufficient to develop high yielding wells. Except for valley floor areas immediately adjacent to impermeable rocks, or adjacent to the lake beds, the ground water development potential for domestic and sfcockwatering uses apjears favorable throughout most of the valley floor lands. Groujid Water Storage Capacity The ground water storeige capacity to a depth of i<-00 feet has been estimated to be approximately i+, 000, 000 acre-feet. How much of this quantity is usable, or how much usable storage exists below ^4-00 feet is not presently known. It is reasonable to asstnne that a significant amount of ground water could be developed. Quality of Ground Water Ground waters in Surprise Valley display a wide range of mineral quality. The ground waters located west of Lower and Middle Alkali Lakes and extending north as far as Lake City are usixally excellent in quality and generally range from calcium to sodium bicarbonate in character. These waters are suitable for most beneficial uses. In the area east of Middle Alkali Lake and along the southern and western edges of Upper Alkali Lake, there are many thermal artesian wells and hot springs which yield poor quality waters. These waters range from sodium sulfate to sodium sulfate chloride in character. Except for these thermal waters, the remainder of -179- the ground waters located west of Upper Alkali Lake and those located north of the lake are generally of excellent mineral qiiality emd siiltable for most beneficial uses. These waters range from sodium to calcium bicarbonate in character. Ins^Ifficient data are available to establish the quality of ground water east of Upper Alkali Leike and along the east side of the valley south of Forty-nine Creek. Water Quality Problems The thermal artesian wells and hot springs in this valley yield waters high in electrical conductivity and contain high concentrations of sulfate, boron, fluoride, and soditmi. Some of these waters also contain excessive arsenic. These waters are considered hazardoiis for both domestic and irrigation use. The location where these waters are found is shown on Plate 23. As these highly mineralized waters are artesian, they are under sufficient pressure to readily migrate through improperly constructed or maintained wells into adjacent good quality waters. Good well construction and sealing practices can keep this threat to a minimum. Increased ground water extractions and the resultant depression of water levels might also lead to the migration of these poor quality waters into adjacent areas of good quality ground water. The surface waters in the Alkali Lakes are also very poor in quality and unsuitable for most beneficial uses. Changes in water levels may reverse existing ground water gradients so that the poor quality lake waters could migrate into and imjjair adjacent ground waters. A few wells and springs associated with the fault zone west of Lower Alkali LaJce yield waters containing excessive concentrations of fluoride or boron. There are a few additional wells not associated with the fault zone which also contain excessive concentrations of fluoride or boron, but these appear to be only local impairments. -180- Conclusion At the present level of agricultioral developnent, additional q\iantlties of irrigation water to supplement streamflow are usvially required during a portion of the growing season. The pi^sent irrigation water supply is derived primarily from snowmelt in the Warner Mountains. Snow- melt and resultant rapid runoff usually take place only during the begin- ning of the growing season. Thtis, additional irrigation water may he required as early as the first of May in some areas euad not until July in others. As the general steepness of the east side of the Warner Mountains precludes the construction of sufficient surface water storage facilities, and as importation of water appears infeasible, ground water appears to be the only logical source of additional supplemental irrigation water. Fortxmately, large quantities of available ground water underlie most of the areas requiring supplemental irrigation water. But, two possible detrimental conditions need to be considered. The first is that poor quality water will probably be encountered in the area indicated on Plate 23. The second is that althotjgh available recharge apparently is not a limiting factor under the present level of ground water development, there are indications that such a condition will arise with increased \ise unless additional recharge facilities are constructed. Insufficient data con- cerning the east side of the valley floor are available to form an opinion of the groxmd water development potential of this area, except for the quality of ground water underlying the area northerly from Cedar Plionge. Along the east side of the valley floor, the main water-besu-ing formation appears to be the Forty-nine Camp formation. A i«reliminary opinion con- cerning this formation is that it will yield moderate quantities of ground water to wells, but recharge of this formation is insvifficient for a sus- tained high level of ground water development. -IfiL- / It is concluded that the basic data collection activities of the Department of Water Resotirces shoiild be continued in order to facilitate future quantitative and qualitative analyses of the ground vater basin. Encouragement should be offered to local agencies in their efforts to develi the ground vater potential in the manner best suited to local problans and in accordance with information in this bulletin. - -182- Madeline Plains Ground Water Basin Madeline Plains ground water basin Is located In northeastern Lassen County and consists of Madeline Plains, Dry Valley, and Grasshopper Valley. The valley floor of Madeline Plains is uniisna3.1 y flat and lies at an elevation which ranges from about 5,285 feet to 5,300 feet. Madeline ELalns is roughly "L" shaped. The north-south segment, \rtiich constitutes the Madeline ground water subbasin is about l6 miles long and from 5 to 8 miles wide. The east-west segment named the Ravendale subbasin, is about 17 miles long emd about 8 miles wide. The boundary between the two sub- basins is near Terma, as shown on Plate 25. To the west of the Madeline subbasin is the Dry Valley subbasin, which is an elongated valley about 7 miles long and 1 mile wide. The floor of Dry Valley lies at an average elevation of about 5,290 feet. It is partially separated from Madeline subbasin by Dry Valley Ridge, \rtilch rises to an elevation of about 6,000 feet. Grasshopper Valley subbasin lies to the west of Dry Valley subbasin. The floor of Grasshopper Valley is about 9 miles long and 3 miles wide; it lies at an average elevation of about 5,300 feet. Grasshopper Ridge, which rises to an elevation of about 5,800 feet, partially separates Grasshopper Valley from Dry Valley. A rugged, mountainous area completely surroxmds Madeline Plains, Dry Valley, and Grasshopper Valley. The mountains are dominated by the old volcanic cones of Observation Peak, elevation 7*9^^^ feet, McDonald Pe6ik, elevation 7,931 feet, and Heavey Moxmtain, elevation 6,^6k feet. Madeline Plains is a basin of internal drainage; it has no surface outlet. Streams in the Madeline Plains area flow only intermittently during or immediately following periods of rainfall. -183- Surface exposiires of various geologic formations of the Madeline Plains area are shown on Plate 2k, Areal Geology, Madeline Plains Ground Water Basin. Plate 25, Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Madeline Plains Ground Water Basin, Spring I960, is a generalized picture of the elevation of ground water within the ground water basin. Plate 26, Potential for Development of Ground Water, Madeline Plains Ground Water Basin, presents the preliminary evaluation of the potential for ground water development within this basin. Geologic History In the Miocene epoch, about 25 million years ago, the Madeline Plains area was probably characterized by extensive rolling plains, scattered I lakes, and occasional volcanic cones. By the Pliocene epoch, the area had become the location of an immense lake which stretched far to the north and south of the area. This lake was bordered by volcanic mountain ranges of unknown extent and height. During the Pliocene epoch, the crust of the earth began to shift along numerous faults. At the same time, lava welled up along fissures formed by these faults and spread over much of the lake bed. New volcanoes slowly began to be built around the fissures and released billowing clouds of ash and glowing streams of lava. The volcanoes continued to erupt in the Pleistocene epoch and then their activity diminished and finally ceased. The most prominent of these extinct volcanoes today are McDonald Peak, Observation Peak, and Heavey Mountain. During the early Pleistocene epoch, drainage from the I^Iadeline Plains area became blocked by lavas. Subsequently, a lake formed and grew in size until it attained a depth of about 120 feet and had a water surface -l8it- eleyg.tion of 5>^00 feet. This lake, named Lake Madeline, covered all of Madeline Plains, Dry Valley, and Grasshopper Valley. For a short time, the lake is believed to have overflowed across the lava field south of Ravendale and into Secret Valley by way of Snowstorm Canyon. At the close of the Pleistocene epoch, the climate became drier, and the lake slowly dried up. Today all that remains of Lake Madeline is its dry lake bed. Water- Bearing Formations Table I5 briefly describes the geologic formations in the Madeline Plains area. Of these, the principal water-bearing formations are Flio- Pleistocene and Pleistocene lava flows. Pleistocene lake and near- shore deposits, and Recent valley sediments. Plio-Pleistocene and Pleistocene Lava Flows . Plio-Pleistocene and Pleistocene lavas form the extinct volcanoes and the lava fields surrounding much of Madeline Plains, Dry Valley, ajid Grasshopper Valley. Here, the lavas form extensive upland recharge areas. The lavas also underlie the valley floor areas, where they are interbedded with lake dejKJsits. In these latter areas, because the lavas are moderately to highly permeable, they serve as Important aquifers and are capable of yielding large q\xantlties of groixnd water to wells. Pleistocene Lake and Mear-Shore Deposits . Fine grained lake deposits are present in the central portions of Madeline Plains, Dry Valley, and Grasshopper Valley. The flat-lying lake deposits are of low permeability and may be as much as 1,000 feet in thickness. Because of their low perme- ability, the laJce deposits act as confining beds to ground water contained in interbedded basalt flows. The lake deposits themselves usually yield sufficient water only for domestic and stockwatering purposes. -185- GEOLOGIC FORMATIONS IN MADELINE PLAINS GEOLOGIC AGE APPROXIMATE THICKNESS IN FEET PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS Highly permeable and located above water table; hence acts only to recharge underlying Qal ! Unconsolidated allt, sand, gravely and clay. Moderately permeable. Yields moderate quantities of ground water to shallow wells. Of ; Unconsolidated, poorly sorted silt, sand, and gravel, with sons clay. Moderately permeable. Yields moderate quantities of ground water to shallow wells. Qpvp i Ifticonsolidated volcanic fragments occurring aa cinder Highly permeable but of small areal extent; thus of little importance to ground water. Qpvb ; Highly jointed vesicula basalt flows. Contains nume ous scoria sones. Permeability ranges from moder- ate to high. May provide large quantities of water to wells. Acts as recharge area, PS ! Slightly consolidated Deach deposits of sand and gravel with minor amounts o silt and clay. Moderately permeable moderate supplies shallow wells. yields Qpl t Slightly to moderately consolidated clay, silt, and fine sand with interbedded burled lava flows. Alkali often present. Low permeability. Generally yields small quantities of water to wells; may yield large quantities of water to wells intercepting buried lava flows. Tftvb Jo: ,vb t Cones and flows of olnted, vesicular basalt. Sone flows are Interbedded with lake deposits. Highly permeable. Burled flowi provide large amounts of groiind water to wells. Acta to recharge adjacent valley ^ Of moderate permeability. Locally provides water to springs. ow permeability and of little in^jortance to ground water* TpYp ; Pale-colored, bedded tuff Tpl ! Pale-colored ash-rich and tuffaceous beds. Outcrops only in Tuledad Valley. Tvr: Li^t-colored, rhyolite . Tttvb ! Flows of Jointed basalt. Tmvp : Bedded mudflows, tuff, ashy sandstone, and dlatomlte. May be correlative to part of Turner Creek formation* Trnte t Massive mudflows and tuffs with beds of ashy sandstone and diatomlte. Includes minor flows of basalt and andesitc Low permeability and of little in^ortance to ground water. Low to moderate permeability. May yield moderate quantities of water to domestic and stock well a. Essentially impermeable. Low permeability and of no portance to ground water. Of low overall permeability. I few more permeable beds may yield limited quantities of ground water to domestic and stock wells. Of low overall permeability, h few more permeable beds may yield limited quantities of ground water to domestic and stock wells. 186 Coarse grained near-shore deposits form a narrow strip around the margins of Madeline Plains, Dry Valley, and Grasshopper Valley. The deposits are estimated to be about 75 feet thick; however, in many cases they consist of a thin veneer only a few feet thick overlying older materials. The near- shore deposits are moderately permeable, but because most of them occur above the water table, they serve primarily as recharge areas. Locally, the deposits may be capable of yielding moderate amounts of water to shallow wells. Recent Valley Sediments . Recent valley sediments include alluvial fans and intermediate alluvium found around the margins of the valley floor areas. Both deposits are quite limited in areal extent and seldom exceed 100 feet in thickness. Alluvial fans occur below the mouths of canyons and are of moderate permeability. Althoxigh the intermediate alluvium generally is finer grained, it is also moderately permeable. Both types of deposits yield moderate amoimts of water to shallow wells. Influence of Geologic Structure on Ground Water The principal structure affecting groimd water in the Madeline Plains area is the layered, sloping lavas which radiate outward from the extinct volcanoes. The layers contain permeable zones along which ground water moves from areas of recharge to and beneath the valley floor areas. The northeastern amd southwestern portions of the Madeline Plains area shown on Plate 2k is transected by roughly parallel faults trending in a north- south direction. These faiilts appear to have only minor effects on ground water in Madeline Plains ground water basin. One effect is the exposure of relatively impermeable pyroclastic rocks along the eastern edge of Madeline Plains. Another group of faults crosses much of the remaining area shown on Plate 2k. This group is oriented in a northwest-southeast direction. The Likely fault, one of the larger faults in Northeastern -18T- California, is one of this group. Movement along several of the parallel faults of this group has uplifted the ridges that separate Grasshopper Valley, Dry Valley, and Madeline Plains subbasins. These ridges may partially restrict ground vater movement between the subbasins . It is not known how many faults pass beneath the floor of Madeline 12 3 Plains. Geologic section A-A -A -A , presented on Figure 22, shows the probable geologic structural conditions to a depth of 1,500 feet below the ground surface. Geologic Section B-B , presented on Figure 23, shows the probable geologic structural conditions southwest of the town of I«fa.deline. Recharge and Movement of Ground Water The recharge areas, shown on Plate 25, consist of Plio-Pleistocene basELlts. Precipitation which infiltrates the recharge areas percolates down- ward and then laterally to recharge the ground water basin.. Wells located in certain portions of the upland recharge areas may yield sufficient simounts of water for stock and domestic uses. Portions of the upland recharge areas supply springs which flow from joints and fractures in the lavas surrounding the valley floor areas. These springs, especially those in the southern and western parts of Grasshopper Valley, contribute a portion of their flow to the ground water body by infiltration in the valley floor below the springs. Mean seasonal precipitation ranges from 10 to 12 inches per year over most of the valley floor and from 12 to ik inches per year over the recharge areas. Precipitation at the comraiinity of Madeline averages 11 inches per year with a recorded minimum and maximum of about 6 and 22 inches, respectively. Similar variations in year to year precipitation are to be expected throughout the Madeline Plains area. Insufficient ground water elevation data were available to determine lines of equal elevation of water in wells for Grasshopper and Dry Valley sub- basins emd for much of the Madeline and Ravendale subbasins. -188- MADELINE PLAINS LENGTH IN MILES See Plate 24 for location of s Figure 23. GENERALIZED GEOLOGIC SECTION B-B' MADELINE PLAINS GROUND WATER BASIN -100- Present Use of Groimd Water At the present level of agricvilttiral develojinent of the l80,000 axjres of valley floor lands in the Madeline Plains groxmd vater basin, only 6,000 acres are irrigated. These lands receive irrigation water primarily frcOT the diversion of springs, partially regvilated streamflovf, and svtrface water storage. Pumped ground water is used in some ajreas as a supplemental irrigation water supply. Only six of the 91 water wells located within the "basin have been classified as irrigation wells. The remaining wells are used primarily for domestic and stockwatering purposes. The maximum reported yield from a well within the basin is 3*800 gallons per minute. However, this yield is far greater than the average yield of about 600 gal Ions per minute produced by irrigation wells in Madeline Plains. Yields from domestic and stock wells axe much lower. Ground Water Development Potential Within the valley floor area of the Madeline Plains grovind water basin, all four zones of potential for development of ground water are present. The area of the valley floor in each classification is shown on Plate 26. Available ground water data were insufficient to determine the potential for ground water development in certain areas; however, these areas e^re expected to range from "B" to "C" in ground water development potential. The general conditions -vrtilch presently govern the potential for development of ground water within each zone found in this basin are discussed below. "A" Zone . The "A" Zone aj:^a shown on Plate 26 is bordered by a recharge area over which moderate precipitation occurs. Its classification as "A" Zone is based primarily upon a reported yield of 3*800 gallons per -191- minute from a well located within this area. This well intercepts bxiried lava aquifers interoedded within the lake deposits. Properly constructed and developed wells several hundred feet in depth which intercept lava aquifers should produce high yields of ground water. "B" Zone . Four scattered areas in the Madeline Plains ground water basin fall within the "B" Zone classification. All four areas depend on underlying aquifers having reasonably high permeabilities and proximity to good recharge areas. The "B" Zone area in the northern part of the Madeline subbasin may be partially recharged by surface water irrigation return flow. Properly constinicted and developed wells drilled to depths of several hundred feet into intermediate alluvium, buried lavas, and near-shore deposits should result in supplies sufficient for most irrigation requirements. "C" Zone . Wells located in the "C" Zone areas have only a fair development potential. Limited irrigation yields are possible, but should not be expected. However, the chance of the discovery of buried lava aquifers is possible, which coiild increase ground -vrater production from these areas. "D" Zone . The "D" Zone areas have the pooi-est groimd water devel- opment potential, and wells located in tMs zone are not expected to produce more than limited supplies for domestic or stocl^watering purposes. The location of a well near outcroppings oi relatively impermeable pyroclastic rocks may result in the well producing little or no ground water. General . The overall ground water development potential for Madeline Plains is only moderate. Although the opportunity for recharge is essentially good, precipitation in the drainage area is relatively low. Because of this i it is believed that sustained yields from high capacity wells would result 4 h in mining of ground water rather than use followed by natural replenishment. , -192- Ground Water Storage Capacity The ground water storage capacity to a depth of 600 feet has been estimated to be approximately 2,000,000 acre-feet. How much of this quantity Is usable, or how much usable storage exists below 600 feet is not presently known. It is reasonable to asstnne that a significant amount of ground water could he developed. Queility of Ground Water The ground water in Madeline Plains basin is general 1 y of good quality and should be suitable for most beneficial uses. While bicarbonate is the predominant anion, no cation predominates although calcium and magnesi\m ions are more prevalent than is sodixjm. Insiifficient data are available to evaluate the quality of ground water in Grasshopper or Iiry Valleys . Water Quality Problems About one out of everj'- four wells in this basin yields water which shows some localized impairment. Most of these waters have high electrical conductivities indicating high salinities. Several show excessive iron and boron concentrations. The Madeline Plains ground water basin is a closed basin; thus in- creased use and reuse of water will probably' result in progressive impairment of the quality of groimd water. Ultimately the salinity of the ground water in this basin could increase to the point where the ground water becomes unsuitable for beneficial use. Conclusion Based upon the limited data available, the development of some supplemental irrigation supplies from the Madeline Plains ground water basin -193- appears to be promising. The relatively low precipitation owr the entire drainage basin limits the possible recharge of the groimd vater basin. Adequate irrigation yields may be expected from the "A" and "B" Zone areas from properly constructed veils. It is concluded that the basic data collection activities of the Department of Water Resources should be continued in order to facili- tate future quantitative and qtialitative analyses of the ground water basin. Encouragement should be offered to local agencies in their efforts to develop the ground water potentisiL in the manner best suited to local problems and in accordance with information in this bulletin. -19l»- Wlllov Creek Valley and Secret Valley Ground Water Basins Willow Creek Valley and Secret Valley ground vater "basins are located in central Lassen Coimty. The more westerly. Willow Creek Valley, has an average elevation of about 4,900 feet. It is roughly 7 miles long and k miles wide. The valley is "bounded on the north by Horse Lake ^fo^mtain and on the west by Black Mountain, Deans Ridge, and Mahogany and Greens Peaks. On the southern boundary, Antelope Mountain and Susan Peak are foimd. Tunnison Motmtain forms the eastern boundary. To the west, beyond Black Mountain, is Eagle Lake. Willow Creek, originating from springs northwest of Willow Creek Valley, flows southeasterly through the valley. Secret Valley is located about 15 miles eaist of Willow Creek Valley. Secret Valley is about 9 miles long and 6 miles wide. The floor of the valley lies at an elevation of about i<-,400 feet. The valley is bordered by Five Springs Mountain and the Skedaddle Mountains on the east and south, respectively, and by Snowstorm Mountain on the north. To the west is South Plateau, a broad lava field. Secret Creek originates north of Secret Valley, flows southwesterly through the valley, and continixes southwesterly through Balls Canyon. The major tributary to Secret Creek is Snowstorm Creek, which flows into Secret Valley from the northwest. Surface exposures of the various geologic formations of the Willow Creek Valley and Secret Valley area are shown on Plate 27, Areal Geology, Willow Creek Valley and Secret Valley Ground Water Basins. Plate 28, General- ized Lines of Equal Elevation of Water in Wells in Aquifers, Willow Creek Valley and Secret Valley Ground Water Basins, Spring I96O, is a generdized picture of the elevation of ground water in Willow Creek Valley ground water basin. No elevation data are available for Secret Valley ground water basin. Plate 29, Potential for Development of Ground Water, Willow Creek -195- Valley and Secret Valley Groimd Water Basins, presents the preliminary evalua tions of the potential for ground vater development within Willow Creek Valley ground water basin. There were insufficient data available to detei^pi, the potential for ground water developnent in Secret Valley. Geologic History During the early Tertiary period, the Willow Creek VeOley-Secret Valley region was a land of many volcanoes and lava fields. In the Pliocene epoch, the region became the site of a vast irregular lake which contained volcanic islands and probably was bordered by volcanic mountain ranges. Dur ing the middle or late Pliocene, the crust of the earth in the vicinity of Willow Creek Vf^ley began shifting sdong faults. This movement was associated with continxiing volcanism. In contrast, the Secret Valley area remained relatively stable except for the continued construction of volcanoes. By the beginning of the Pleistocene epoch. Willow Creek Valley had formed and was receiving alluvial and volcanic debris. The northern part of the veJJ.ey was subsequently covered by a large lava field. During the latter part of the Pleistocene epoch. Eagle Lake probably drained into Willot Creek Valley throiogh a wide canyon north of Deans Ridge. | After the close of the Pleistocene epoch, volcanic activity caused Black Motmtain, located between Eagle Lake and Willow Creek Vedley, to IncreiM in size. The mountain and associated lava flows eventually blocked the surfiM outlet of Eagle Lake. Lava also poured into the western portion of Willow Creek Valley. With this last eruption of lava, volcanism ceased in the Willov Creek Valley area; however, faulting and eirosion have continued to shape the landscape up to the present time. Secret Valley evolved in an entirely different manner. During the late Pliocene smd early Pleistocene epochs, the area was one of intense -196- volcemism. Lavas spr^ead over the old Pliocene laketed, and large volcanoee constriicted cones 2,000 to 3»000 feet above the intervening lava fields. Streams eventually; eroded canyons throiigh the lava field located between Snowstorm, Shaffer, and Skedaddle Mountains. Erosion hy these streams re- exposed the Pliocene lakeheds. Once the relatively soft lakeheds were exposed hy Snowstorm and Secret Creeks, the overlying lavas were easily undermined and the canyons slowly widened to form Secret Vedley. Erosion has continued to broaden the valley througjiout the Pleistocexie and Recent epochs. Water -Bearing Formations Table 16 briefly describes the geologic formations in the Willow Creek Valley-Secret VeuLley area. Of these, the water-bearing formations are Plio-Pleistocene to Recent lava flows. Pliocene lake deposits, and Recent valley sediments. Plio-Pleistocene to Recent Lava Flows . Moderately to highly permeable Plio-Pleistocene to Recent betsalt flows cover extensive areas in the Willow Creek Valley-Secret Valley area. These lavas border most of Willow Creek Valley, except for the soxithwestern margin. The lavas form areas of ground water recharge and act as aquifers beneath the southeastern and perhaps the northern portions of the valley. The Recent lavas appear to transmit water from Eagle Lake into Willow Creek Vedlfey, soiae of lAich probably appears at the n\miei*ous springs that feed Willow Creek. Secret Valley is surrounded by Plio-Pleistocene and Pleistocene lavas. They form the low lying plateaus east and west of the valley and the volcanic cones to the north and south. The older lavas are interbedded with Pliocene lake deposits beneath the valley floor. These older lavas are the principal aquifers in Secret Valley and may yield large amounts of confined -197- GEOLOGIC FORMATIONS IN WILLOW CREEK VALLEY AND SECRET VALLEY WATER-BEARING CHARACTERISTICS High pernsablllty but undorlal by In^ermeable material. Of no Importazico to ground watt Very low permeability. Of »«' little importance to ground i Moderate permeability but of little Importance to ground water. In Secret Valley, of low peri ability and yields small amoun of v/ater to wells. llow Creek Valley, model water to veils. Hie lavas svirrounding Secret Valley act as upland recharge areas and give rise to numerous springs located along the northern edge of the valley. Pliocene Late Deposits . Pliocene lake deposits underlie all of Secret Valley and probably occur beneath a cover of several hundred feet of Recent sediments in Villow Creek Valley. In general, these deposits are of lov overall permeability and act as aqviicludes in Secret Valley, confining vater in older flows in the Plio-Pleistocene basalt. !Ihe lake deposits themselves yield sufficient water only for domestic or stock purposes. A few gravel lenses are present in the lake deposits in Secret VcJley. These lenses are moderately permeable and covild provide moderate quantities of groTjnd water to wells. Ihe relative importance of the Pliocene leike deposits in Willow Creek Valley is not known at this time. Recent Valley Sediments . Recent valley sediments in Willow Creek and Secret VaQleys inclvide basin deposits, alluvial fans, and intermediate alluviimi. In Secret Valley, these deposits are generally very thin and tend to be of low permeability, and thus are of little importance to gro\md water. Locally, the materials provide s\iff icient vater to shallow veils for domestic and stockwatering purposes. The intermediate alluvium and alluvial fans in Willow Creek Valley are up to 250 feet thick. Ihe deposits are moderately to highly permeable emd yield moderate to large amounts of water to wells. Ihe dejwsits underlie most of the southwestern half of the valley. Bie northeastern part of the valley is mostly underlain by basin deposits vhich are low in permeability and are poor producers of ground water. Influence of Geologic Structure on Ground Water The geologic structures of Willow Creek Val l ey and Secret Valley are vastly different. Willow Creek Valley is a ccaaplexly faulted depression -199- 4 I controlled by a northvest-southeast fault system along its southvestern margin. The northwest-southeast system forms a series of stepped fault blocks along vhlch the yaXley was depressed and the granitic rocks of Deans RLdge correspondingly elevated. The faults in Willow Creek VetLLey have little apparent effect oa groiand water. Generalized geologic section A-A , presented on Figure 2l«-, shows the probable geologic structured, conditions to a depth of about 1,200 feet below the valley floor. Secret Valley, In contrast to Willow Creek Valley, is an eroslonal valley that has undergone very little modification by faulting. The principtil structures affecting ground water are the layered, sloping lavas radiating trcm the centers of the extinct volcanoes north and south of the valley. The oldest of the lavas extend beneath the veuLLey floor where they serve as important aqiilfers. The younger lavas occ\ar only arovmd the edge of the valley idaere they rechsurge springs and underlying older rocks. The Pliocene lake deposits in Secret Valley are gently folded. The effect that this folding has on ground water is unknown at the present time. Generalized geologic section B-B , presented on Figure 25, shows the probable geologic structural conditions to a depth of about 1,000 feet below the valley floor. Recharge and Movement of Ground Water Upland recharge areas, shown on Plate 28, are ccanposed principally of Recent, Pleistocene, and Plio-Plelstocene basalts. Precipitation infiltratta the upland recharge £u:*eas and then percolates laterally into the valleys. Available precipitation data Indicate that within the Willow Creek Valley drainage area, frcm 10 to 12 inches of mean seasonal precipitation can be expected, \^ile in the Secret Valley drainage area, only 6 to 6 Inches appear likely. Willow Creek Valley ground water basin contains both \mconf ined azKl confined ground water bodies. Sediments which comprise most of the valley -200- fill are generally saturated to within a few feet of the ground surface and provide readily available supplies of ground water for stock said domestic use. Limited water level data indicate that grovind water genersuLly moves toward Willow Creek. Flowing wells, which indicate the presence of confined ewiuifers, have "been drilled in the southeastern part of the valley. It is believed that the confined aquifers are buried lava flows which may be Pleistocene basalt. Althovigh there are no ground water elevation data available for Secret Valley, it can be assumed that gro\ind water generally moves from the upland area to and beneath the valley floor. It then moves toward Secret Creek and eventually leaves the valley by way of BclUs Canyon. Some groiind water may leave the val ley by way of subsurface outflow beneath South Plateau. Present Use of Grotind Water The portion of Willow Creek Valley ground water basin which is over- lain by valley floor lands encompasses about 12,500 €u:res, all of ^ich aJre classified as irrigable. Hie present available water siipply, which is derived mostly from sxirface water, limits irrigation to about If, 000 acres. Only three irrigation wells have been located in the valley, and they are used to si?iplement available siirface supply rather than irrigate additional lands. The best irrigation well in the valley is reported to have developed 1,200 gallons per minute. Only about ten domestic and stock wells have been located in the valley. Secret Valley ground water basin contains about 22,000 acres of irrigable valley floor lands. At the present time there are about 3>000 irrigated acres in the valley. Most groiand water in the valley is used for domestic and stockwatering purposes. However, there are at least two irrigation wells in the valley. -201- WILLOW CREEK VALLEY ! 'J + +7+^+^*1- Xt-Vi- ^v r-Alluviol Fon Bosin Dopositt-y . „(.Gronitic Rockst t t.t »-iFe »^^._.__i_._i_^ ._j l . m. -- - ^ /_ , ^1+ ,.4-4.<.+ U 4-4- + 4 + <-'*^'*-^='i' '-•--— ^'-•- «"■■■" -J' _=-/-. ^li i i-v^ Pl iocene Loke ■ • ■' ^-r^- LENGTH IN MILES See Plate 27 for locotion of section. Figure 24. GENERALIZED GEOLOGIC SECTION A-A' WILLOW CREEK VALLEY GROUND WATER BASIN B r SECRET VALLEY LENGTH IN MILES See Plote 27 for locotion of section. Figure 25. GENERALIZED GEOLOGIC SECTION B-B' SECRET VALLEY GROUND WATER BASIN 202 Ground Water Development Potential of Wlllov Creek Valley Within the veuLley floor area of Willow Creek Valley ground water bcuBin, only the "B" and "C" Zones of ground water development jKjtential are present. The area of the valley floor in each classification is shown on Plate 29. The general conditions i^ich govern the potential in this basin are discvissed below. "B" Zone . Properly constructed wells up to several himdred feet in depth should be able to svtpply moderate quantities of ground water for most irrigation requirements from the alluviCLl fan and intermediate alluvivmi of the "B" Zone. "C" Zone . Restricted irrigation yields are possible in the "C" Zone. If buried lava flows are intercepted, yields of ground water having the magnitude of those of the "B" Zone may be obtAined. General . The overall development potentisil for Willow Creek VtLLley is moderately good. The capax5ity for recharge of the groxmd water beusin is excellent, but precipitation is relatively low. The aquifers in the ground water basin are qviite thick. There is a possibility that subsurface inflow from Eagle Lake may contribute to the ground water within the Willow Creek Valley grovind water bausin. Qiiantities of grotind water sufficient to satisfy ultimate irrigation requirements for Willow Creek Valley are probably available . Grotnad Water Development Potential of Secret Valley There are Insvifficient data avedlable to classify the valley floor area of Secret Valley into the various zones of potentisuL for ground water development. It is estimated that most of the valley floor area w>uld fall in either the "B" or "C" Zone categories. -203- Quality of Ground Water Ihe ground water in Willow Creek Valley is generally excellent in quality. It is a well balanced water with no cation predominating; bicar- bonate is the predominant anion. No data are available to detezmlne the quality of ground water in Secret Valley. Water Quality Problems A single shallow well at the southeast end of Willow Creek Valley yields water that has a very high electrical conductivity and an excessive nitrate content. Water from this well is considered to be hazardous for domestic or irrigation use. This well, however, appears to represent only a localized condition of impairment. There are no other known or antici- pated water quality problems in this valley. Conclvtsion Properly constructed wells within "B" Zone areas of Willow Creek Valley ground water basin should be capable of developing ground water in quantities sxifficient for additional irrigation Uise. Wells in the "C" Zone areas generally have a lower potential for developaent of ground water and ccm be expected to supply only limited quantities of ground water for irriga- tion. The recharge axeas are extensive and highly permeable, but avail- able precipitation appears to be insufficient to allow maximum utilization of potential ground water storage capacity. It is concluded that the basic data collection activities of the Department of Water Resources should be continued in order to facilitate fut\ire quantitative and qualitative analyses of the ground water baslxi. Encouragement shoxild be offered to local agencies in their efforts to develQip the groiuid water potential in the manner best suited to local problems and in accordance with infoznation in this bulletin. Honey Lake Valley Groimd Water Basin Honey Lake Valley ground water basin is located in eastern Lassen Coiinty and adjacent western Washoe County, Nevada. The valley is bounded by the Diamond Mountains on the west and southwest, the Fort Sage ajid Virginia Mountains on the southwest and southeast, Antelope Moiontain ajid Shaffer Mountain on the north, and the Amedee and Skedaddle Mountains on the northeast. The California portion of Honey Lake Valley is about ^5 miles in length and 10 to 15 miles in width. Honey Lake, which is usually dry during the sioramer months, covers an area of about 93 square miles and is a dominant feature of the valley. The floor of the valley ranges in elevation from less than ij-,000 feet along the shore of Honey Lake to about 4,200 feet at the edge of the valley floor. Major tributaries to the valley are Long Valley Creek, Susan River, and VJillow Creek. Long Valley Creek drains a large arid region lying to the southeast of Honey Lake Valley. Susan River drains the volcanic plateau located to the west of Honey Lake Valley. Willow Creek drains Willow Creek Valley which lies to the north of the Honey Lake area. Surface exposures of the various geologic formations of the Honey Lake Valley area are shown on Plate 30, Area! Geology, Honey Lake Valley Ground Water Basin. Plate 31, Generalized Lines of Equal Elevation of Water in Wells in Aquifers, Honey Lake Valley Ground Water Basin, Spring I96O, is a generalized picture of the elevation of groiind water within the groiond water basin. Plate 32, Potential for Development of Ground Water, Honey Lake Valley Gro;md Water Basin, presents the preliminary evalimtions of the potential for ground water development within this basin. Areas of hazard because of poor quality water are also indicated on Plate 32. -205- Geologic History At the beginning of the Tertiary period, 6o million years ago, the Sierra Nevada vbs probably a low range of hills. At some time during the Tertiary, the area now known as Honey Lake Valley slowly began to subside. By the Pliocene epoch, the valley and a large area to the north were covered by an immense body of water surrounded by active volcanoes. The lake may have had a northwesterly outlet to the sea. During the middle and late part of the Pliocene epoch, the crust of the earth began shifting along numerous faults, and the Diamond Mountains and the Sierra Nevada were tilted upward. Volcanic activity had ceased in the Diamond and Fort Sage Mountains, but volcanism became more active to the north and new volcanoes were built. The continued faulting and volcanism restricted the Pliocene lake so that it no longer had an outlet to the sea. Uplift along the Antelope MoiKitain fault during the late Pliocene and early Pleistocene epochs left a part of the old Pliocene lake bed perched about 1,000 feet above the present valley floor. During the Pleistocene epoch, a second lake, named Lake Lahontan, covered all of Honey Lake Valley as well as adjacent areas of northwestern Nevada, Lake Lahontan had a maxim\am surface elevation of about l4-,ii-00 feet and a maxim\;im depth of about UOO feet in the Honey Lake basin. The water surface of the lake probably fluctuated a great deal during the Pleistocene epoch. In fact the lake may have dried up during the interglaclal stages only to reappear again during the succeeding glacial stages. At the close of the Pleistocene epoch, volcanoes adjacent to Honey Lake Valley ceased to erupt and became dormant. With the beginning of the Recent epoch, the climate of the region gradually became more arid. Lake Lahontan slowly began to dry up until today only a few remnants are left, such as Honey Lake in California, and Pyramid and Walker Lakes in Nevada. .206- Water-Eearlng Formations Table 17 briefly describes the geologic formations in Honey Lake Valley. Of these, the principal water-bearing formations are Pliocene lake deposits, Plio-Pleistocene and Pleistocene lava flows, Lahontan lake and near-shore deposits, and Recent valley sediments. Pliocene Lake Deposits . Pliocene lake deposits underlie nearly all of Honey Lake Valley and the lava fields foimd to the north. Most of the valley fill consists of these deposits, and they reach a maximiom thick- ness of about 5,000 feet near the northwestern end of The Island. The deposits are usually covered by several hundred feet of LaJiontan lake deposits and Recent valley sediments and thus are usually encountered only in deeper wells. In general. Pliocene lake deposits are of low permeability, but locally, may yield moderate q^lantities of confined water to wells. Plio-Pleistocene and Pleistocene Lava Flows . Plio-Pleistocene and Pleistocene lavas form the lava fields and extinct volcanoes bordering Honey Lake Valley on the north. Some of the lavas are interbedded -vrLth Pliocene and Lahontan lake deposits. The lavas are moderately to highly permeable; l'-' and in the volcanic terrain north of the valley, they act as upland recharge areas. The lavas also serve as important confined aquifers in the north- western and northeastern portions of Honey Lake Valley, where they yield large amounts of ground water to irrigation wells. Lahontan Lake and Near-Shore Deposits . Lake and near- shore deposits up to 700 feet thick accumulated diiring the Pleistocene epoch when Honey Lake Valley was occupied by Lake Lahontan. Coarse grained near-shore deposits form a discontinuous belt around the edge of the valley to an elevation of about l4-,i|-00 feet, and relatively fine grained lake deposits occupy the central part of the valley. The near-shore deposits are highly permeable and frequently occur above the water table where they act as important recharge -207- GEOLOGIC FORMATIONS IN HONEY LAKE VALLEY PHYSICAL CHARACTERISTICS WATER-BEARING CHARACTERISTICS £8dt Loose* wlnd-blovn sand. lig^ly pemi«able but located above water tablet hence con* tains little water. Ql ! Unconsolidated ailt aid clay» contains alkali. Very low permeability and of little in5>ortance to ground water. Qb ; Unconsolidated sand, silt, and clay. Often contains alkali. Low permeability. small amounts o domestic wells. Qal ; Unconsolidated sand, silt, and gravel with lenses of clay. Moderate permeability, Ylelda small to moderate quantities of water to wells. £ls: tfricons oil dated mixtures of rock, sand, and clay. Moderate permeability. May moderate quantities of wat to wells in Hidden Valley. ftf : Unconsolidated gravel, sand and silt, with some clay iKiaes. Moderate to high permeability. Yields large quantities of water to wells. May contain confined water. Qps ; Unconsolidated, poorly cemented, bedded gravel, sand, and silt. Highly permeable. Frequently occurs above water table. Where saturated yields large quantities of water to wells and suays, ftpl ! Poorly consolidated, bedded sand, silt, and clay. Permeability ranges from low to high. Contains important aquifers in Honey Lake Valley Often yields large quantities of water to wells. Qpvb ; Jointed basalt flows talning zones of scoria. Moderate to high permeability. May yield large quantities of water to wells. Acts as fore< bay for ground water recharge. Qpvp : Bedded mudflows and tuffs Low permeability, unimportant to ground water. TQvb ! Jointed, fractxxred flows of vesicular basalt with some pyroclastic rocks. Moderate permeability, may yield moderate amounts of water to wells. May contain confined water , Inqpor tant as f orebay for ground water recharge. Tftvp ; Pale-colored bedded tuff. Unin^ortant to groimd water. Tgl; Bedded, consolidated sand- stone, tuffaceous siltstone and diatomite. Oenerally of low perneablllty. Locally may yield moderate quantities of water to wells« Contains confined water. Essentially impermeable. Tsvb, Tsva, Tsvp. Tsv ; Flows o fractured basalt, andesite, and minor amounts of other types of lava. Massive mud- flows and tuffs* Pernaability ranges from poor to moderate. Basalt is generally above zone of saturation, is underlain by impermeable rock, and is unimportant to ground water, A few areas may con- tain perched ground water, Andesite and pyroclastic rooki 8ure essentially impermeable. Te£: Semi -consolidated gravel* sand, and clay. Low to moderate permeability. Yields water to many springs* Not important to ground water in Honey Lake Valley. Low permeability. May yield small quantities of ground water to wells. JKgr t Massive, poorly Jointed otorite. Locally weathered and decomposed. Essentially Inqpermeable* Impermeable where fresh. DeooM- posed rook may yield small quantities of water to wells and siuops. areas. I'/here saturated, they often yield large amounts of water to wells and sunips. The lake deposits contain a large number of highly permeable sajid beds in the area northwest of Honey Lake and also in and just north of Long Valley. These sand layers form the most important aquifers in the valley as they provide large amounts of water to irrigation wells. In contrast, the lake deposits found east of Koney Lake and north of ITerlong consist mainly of silt and clay of low permeability and are poor producers of ground water. Recent Valley Sediments . Principal Recent valley sediments in Honey Lake Valley include basin deposits, intermediate alluvium, and eilluvial fans. The basin deposits are thin, of very low permeability, and generally are a poor source of ground water. Intermediate alluvium occurs along most of the perennial streams where they enter the valley. The permeability of the intermediate alluvium is moderate, but it is usually less than 100 feet thick and yields only small to moderate amounts of ground water to shallow wells. The alluvial fans are of moderate to high permeability and may be as much as 300 feet thick. The fans yield large amounts of confined and unconfined ground water to irrigation wells, particularly in Long Valley south of Doyle. Other Recent valley sediments include sand deposits. Recent lake deposits, and landslides. These dejxjsits axe all fairly thin ajid of little importance , .'; to groiind water. The main exceptions are the landslides in Hidden Valley. ; ' These landslides are of moderate permeability and yield moderate quantities of water to wells. Influence of Geologic Structiire on Ground Water The major structural featiires of the Honey Lake Valley area are the multitude of major and minor faults. Most of the displacement along these faults has taken place since the latter part of the Pliocene epoch. Most of the faults trend in a northwesterly direction, but north and northeast trend- ing cross faults are not uncommon. The geologic structure of Honey Lake Valley -209^ 11 12 is shown in generalized geologic sections A-A , B-Ir, and C-C -C , shown on Figures 26, 27, and 28, respectively. These sections show the probable structural conditions to a depth of about 2,500 feet below the floor of the ;, valley. Subsurface features shown on these figures, as well as locations of ■■; many of the faults shown on Plate 30, are from interpretation of data from a geophysical survey made of the valley floor area of lioney Lake Valley by * the Department of VJater Resources. - ^ Tlie entire southwestern side of Honey Lake Valley is bordered by the lioney Lake fault zone. This zone consists of a series of parallel faiilts. Vertl cal displacement of at least 8,000 feet along this fault zone is responsible for the uplift of the Diamond Mountains and the formation of the steep escarp- ment that bounds this side of the valley. Other major faults in the valley are the Antelope Mountain, Litchfield, Amedee, and Fort Sage faults. Movement along these latter faults has been from 2,000 to 5,000 feet in a vertical direc- tion. As a resu].t of all this faulting, the basement complex rocks have been broken into four fault troughs within the lax-ge depression that now forms the valley. The largest and deepest trough is centered around Honey Lake. Base- ment rock at the bottom of this trough occurs at a depth of approximately 5,000 feet beneath the laicebed, or 1,000 feet below sea level as shown on Figure 28. The northwestern end of the valley is formed by a trough centered around %■ Johnstonville . Valley fill consists of over 2,000 feet of sediments and .^, interbedded lavas. Geologic section A-A , shown on Figixre 26, crosses this trough. The Long Valley arm is situated in a trough containing nearly U,l+00 feet of fill material. The eastern part of Honey Lake Valley, north of the | Fort Sage fault, is formed by a trough filled with about 2,200 feet of sedi- ments and lavas . Faulting and subsidence of the valley has had a pronoiinced effect on the Pliocene lake deposits. The forces accompanying fault movement have -210- HONEY LAKE VALLEY HIDDEN VALLEY ::::I5»h::3: ^.,,. H — \\U .Ij y »»...♦ . Gronilic Rock, (?)♦ I I I L 10 n LENGTH IN MILES Figure 26. GENERALIZED GEOLOGIC SECTION A-A HONEY LAKE VALLEY GROUND WATER BASIN hi) I I LtiONEY LAKE FAULT ZONEV ' 'l I. t^ . Figure 27. GENERALIZED GEOLOGIC SECTION B-B HONEY LAKE VALLEY GROUND WATER BASIN -211- ^T^ uiotunon tapauiv "h s6u!Jds 40H 99p9UlV sse xomabiH sn A Ls ..^V i|\v f>V>J-''V.'i '■■ ' 's' ' •' ' ' ' wfiiva s osn i33j ni Nouwans buckled these laiie beds into numerous folds as shown dlagranimatically on Figure 28. When the lake beds could no longer absorb these forces by fold- ing, they failed along many small faiilts of low displacement. The overall effect of this folding and faulting has been to arch the Pliocene lake beds upward so that they are now exposed on the ground surface in the vicinity of The. Island. Tiie faults and folds in Honey Lake Valley midoubtedly affect ground water movement. However, present data sire insufficient to determine the detailed effects of these structural features. There appear to be no major fault barriers beneath the valley floor area. This may be because the Lahontaji and yovinger sedimentary deposits probably have not been dis- placed by faulting. Several faults in Honey Lake Valley act as conduits for the upward percolation of mineralized thermal waters. This water feeds Amedee and Wendel Hot Springs and several hot water wells in the southern part of Susanville. The intense faulting along the Honey Lake fault zone has crushed the granitic rocks in many localities, thereby accelerating their weathering and decomposition. The weathered ajid decomposed zones are sufficiently permeable to transmit small quantities of water. These zones are tapi)ed by many domestic and stock wells and also yield water to numerous small springs located along the base of the Diamond Mountains. Recharge and Movement of Ground Water The upland recharge areas, shown on Plate 31, consist of Plio- Pleistocene and Pleistocene basalt flows. Most of the recharge originates as precipitation which infiltrates the basalt and then percolates laterally to and beneath the valley floor area. An vinknown amoiint of subsurface inflow may enter Honey Lake Valley from Secret Valley through Pliocene lake sediments which appear to be continuous beneath the lava field separating the two valleys. -213- Mean BeasonaJ. precipitation over Honey LaJke Valley varies consider- ably, ranging from less than k inches in the eastern portion to about ll+ inches near Sussuiville. Mean seasonal precipitation on the valley floor averages about 8 inches. The eu:id nature of most of Honey Lake Valley is due to a shadow effect caused by the mountains to the west which act as barriers to the prevailing movement of moisture laden storms. The mean seasonal precipi- tation on these mountains varies from 22 inches along the southwest to about kO inches at the headwaters of Susan River. Precipitation on the peaks along the eastern boimdary averages about 12 inches per year. Variation in the amount of seasonal precipitation can be expected to be similar to that at Susanville where a minimum of about 7 inches and a maximvm of about 33 inches per year has been recorded. Honey Lake Valley ground water basin contains both unconfined smd confined ground water bodies, but data to define the separate bodies are lack- ing. Hence, the lines of eqijal elevation of water in wells shown on Plate 31 probably reflect a combination of the two conditions. Because Honey Lake Valley is a closed basin with no surface outlet, ground water movement is Isu^gely controlled by topography, and the general direction of ground water movement is toward Honey Lake. Susan River, Gold Run Creek, and Baxter Creek appear to be effluent streams, i.e., are fed by ground water throughout a portion of their courses. Conversely, Long VsuLley Creek and Skedaddle Creek are apparently influent streams along a portion of their courses and contribute water to underlying aquifers during periods of intermittent flow. Both the effluent and influent streams affect the eleva- tions of ground water and the movement of ground water in the areas adjoining their channels. Flowing wells located along the northern edge of the valley floor south of the Amedee Mountains are probably supplied by ground water confined -2llf- in buried lava aqiilfers vhich are extensions of the lavas comprising the adjacent mountains. Flowing wells located along the southwestern edge of the valley floor tap confined aquifers in the lower portions of all\ivial fans and adjoining near-shore deposits. The essentially unconfined ground water in the vicinity of Herlong appears to be recharged by Long Valley Creek. Wells of the Sierra Ordnance Dejxjt penetrate deep aquifers of confined ground water. The Island is apparently underlain by a shallow perched ground water body on top of the pre-Lahontan lake deposits. Springs in Honey Lake Valley fall into three groiips: springs which flow from joints and fissures in lavas in the northern and eastern parts of the valley; thermal springs which emerge along faults; and springs which result from the interception of the ground surface and the water table. Cady and Bagwell Springs, which are in the first group, furnish part of the water supply for the City of Susanville. Wendel and Amedee Hot Springs are prominent examples of the second type. The many small springs and seeps along the soiithwestern edge of the valley are of the third group. Present Use of Ground Water The major portion of the 21,000 acres of irrigated lands within the valley floor of Honey Lake Valley grovind water basin receive irrigation water from Susan River. Irrigation water is obtained from both storage developments and direct diversion. The present supply of water from Susan River and other streams is insufficient to irrigate the 185,000 acres of valley floor lands classified as irrigable. During recent years, groxmd water has been developed to supplement surface water irrigation supplies. More than 2,600 acres are presently irrigated entirely from ground water. There are presently about 100 irrigation wells and about 500 domestic and stock wells in Honey Lake Valley. ■215- The yields from some of these veils are insufficient for their intended xise, while the yield fraa others exceeds 2,000 gallons per minute. Groxmd Water Development Potential Within the vsilley floor area of Honey Lake Valley ground water basin all fovir zones of potential for development of grovmd water are present. The area in each classification is shown on Plate 32. The general conditions \rtiich presently govern the potential for development of ground water within each zone in this basin are discussed below. "A" Zone. The "A" Zone area located between Siisanville and Johnstonvill is underlain by permeable lake deposits and buried lava aquifers wbich have excellent opportunity for recharge. The "A" Zone areas in the vicinity of Standish and Herlong are believed to be composed of coarse sands deposited respectively by ancestred. streams along the courses of Stisan River and Long Valley Creek. The "A" Zone strea south of Doyle consists of coarse tLLluvied. fan deposits adjacent to Long Valley Creek. Properly constructed and developed wells up to several hundred feet in depth in "A" Zone areas should produce high yields of groiind water. "B" Zone. "B" Zone areas are fairly well distributed throughout Honey Lake Valley, and most irrigation requirements ceua be supplied from the underlying permeable Istke and near-shore dejwsits. If lava aquifers are found interbedded within the lake deposits, the ground water potential of these areas should approach that of the "A" Zone areas. "C" Zone. The "C" Zone areas are relatively small with the exception of the "C" Zone area including Sierra Ordnance Depot. Only limited information is avedlable concerning the subsurface materials in this latter area. !Ilie apparent lower ijermeability eind the limited rechetrge opporttinity, however, restrict its i>otential for ground water development. Wells located in -2L6- J" Zone areeis are expected to have only a fedr development potential. Limited rigation yields are possible but shoiild not be expected. "D" Zone'. Areas classified as "D" Zone are composed of relatively lin deposits of permeable material and are found in areas adjacent to out- jps of impermeable rock. Wells located in "D" Zone areas are not expected produce ground water in quantities sufficient for anything but domestic stock use. General. Honey Lake Valley ground water basin is unique among the 'ground water basins of the Northeastern Counties in that most of the good recharge areas are those with a minimum of precipitation. Areas with higher .precipitation are not recharge areas in most of the region adjacent to 'Honey Lake Valley. The overall groiind water development potential of the valley floor is good, but not as good as it would be if precipitation were greater over the better recharge areas. I ' There are Isirge areas immediately north of Honey Lake lAiere the water table is less than 5 feet below the ground surface. Lowering of the water table in sianmer months and allowing it to recharge in periods of high runoff could increase the yield of ground water from this area. Presently the high water table prevents the infiltration of additional water into the ground water body. Lowering of the water table below the root zone of native vegetation during the growing season wo\ild conserve for other uses the present consumptive use by native vegetation. IHiis is estimated to be about 5 acre-feet per acre per year. Ground Water Storage Capacity Ground water storage capacity to a depth of 750 feet has been esti- mated to be about 16,000,000 acre-feet. How much of this quantity is usable, or how much usable storage exists below 750 feet is not presently known. It is -217- reasonable to assiane that a significant amount of ground vater could be developed. Quality of Groinid Water Ground waters in Honey Lake Valley vary greatly in mineral quality. The groimd waters in the valley south of Herlong and along the southwestern side of Honey Lake are usually excellent in quality and generally range from csLlcium to sodium bicarbonate in character. Similar waters are found south and west of Bald Mountain, near Buntingville and JanesvilJLe. These waters are suitable for most beneficial uses. Good qxiality ground waters are generally found in that portion of the Susaji River drainage area northwest of Bald Mountain, but about 60 percent of the wells in the portion east of Bald Mountain yield poor quality waters. Some of these waters are not reconmended for doauestic use, while others are considered hazardous for irrigation use. A few are considered hazardous for either use. The groimd waters foiond in the valley east of Honey Lake and north of the Southern Pacific Railroad are generally of good quality and are \isually sodium bicarbonate in character. The few wells in the area east of Honey Lake between the Southern Pacific Railroad and Herlong yield poor quality waters of variable character. Water Quality Problems Ground waters in a closed basin such as Honey Lake Valley are con- tinually subject to water quality impairment resulting from use and reiise. With each use some water is lost from the basin but most of the soluble salts remain, and with some uses additional salts are added. As a result, in the lower portions of a closed basin, poorer quality waters are usually found. As shown on Plate 32, two such areas within this basin contain ground waters of -218- hazardous q-uality. The poor quality waters found in these aj^eas show great variation in both character and quality. Available v^ater quality data indicate that although reuse is probably responsible for much of the impair- ment, some of it is the result of mineralized water rising along fault zones. Although waters of usable quality can be found within the two hazardous areas, more often waters containing excessive concentrations of boron, fluoride, nitrate, or an excessive amount of total dissolved solids will be encountered. Continuing reuse of ground waters may in the future cause inci^ased impairment with the result that these waters may be rendered unusable. Scattered throughout Honey Lake Valley are other wells yielding ground waters which contain excessive concentrations of one or more of the following constituents: boron, iron, fluoride, and nitrate. However, these appear to be only localized conditions of impairment. Conclusion Additional development of groimd water in Honey Lake Valley appears promising. Adequate yields for stock and domestic purposes are available from relatively shallow wells throughout most of the valley. Generally, irrigation wells should be several hundred feet deep, and should be gravel packed to give satisfactory yields. Proper well construction and competent well development are essential if optimum yields are to be obtained. Some of the valley floor is underlain by water of poor or doubtful quality. In a closed basin such as this, water quality will continue to be impaired by any development which contributes additional salts. Anticipated fut\ire development in Honey Lake Valley will be accompanied by population growth and expansion of urban and recreational areas. This growth and expansion will increase the demand for available water resources and will further aggravate the adverse salt balance in the basin. -219- Water quality considerations Indicate the desirability of develop- ing methods atnd techniques which will prevent: (l) the high sodium pearcentage waters from damaging the tilth and permeability of the soils; (2) serious problems from developing from industrial and domestic waste disposal; and (3) excessive accumulation of salts. It is concluded that the basic data collection activities of the Department of Water Resovirces should be continued in order to facilitate future quantitative and qvjalitative analyses of the gro\ind water basin. Encouragement should be offered to local agencies in their efforts to develop the ground water potential in the manner best siiited to local prob- lems and in accordance with information in this bulletin. -220- CHAPTER V. CONCLUSIONS Little vas kncjwn concerning the ground vater basins of the north- eastern counties of California prior to this investigation. Consequently, a major portion of the time and money allotted to the investigation was devoted to the collection of basic data. Generally, both the use of ground vater within the area of investigation and the period for Tdiich data are available are insufficient to determine readily the factors needed to evalu- ate properly the sustained yield that could be developed. Preliminary evaluations of the potential for development of ground water were made to the extent warranted by the data collected. Accoanplishments The primary acconrpOLishments of this investigation are the following: 1. Significant new knowledge has been ^ined concerning geologic and groxind water conditions in the northeastern counties. !13iis new know- ledge includes the following: a. Detailed description of physical and water-bearing characteristics of the area of investigation. During the study, ^ geologic units were described. b. Determination of ground water basin and subbasin boundaries. c. Preparation of a quantitative estimate of ground water storage capacity for all but two of the ground water basins. d. Determination of the geologic structiire of the various ground water basins, and publication of geologic structure sections . e. Publication of geologic maps, at a scale of 1:125,000, of the grovmd water basins ajid surrounding territory totaling nearly 9,000 square miles. -221- f . Preparation of a detailed report on the ground water geology of each ground water basin. 2. The* necessary foundation was completed for the co3JLection of data required for continviing groimd water studies. The following specific determinations were made. a. Location and description of wells. b. Detailed classification of wells. c. Surveys to establish an elevation dat\mi point for wells. d. MeasTjrement of water elevations in wells. e. Analysis of water samples to determine suitability for beneficial use. ' f . Location of wells to be used for obtaining data as to depth to ground water and quality of ground water vmder the department's continuing ground water measure- ment and ground water quality monitoring programs. 3. Preliminary evaluations were made of the potential for ground water development in the basins investigated. Four zones. A, B, C, and D, ranking from high to low, were established. Plates shoving the estimated potential for ground water development indicate the classification for eeich i area investigated. fi k. Experience gained during this investigation will expedite the conduct of future groiind water investigations in the northeastern counties. * i Conclusions | i- In general, the extent and intensity of ground water development f in the northeastern mountain valleys is low and does not constitute a - significant draft on the available ground water resources. TliiR is indicated by the very small changes in water levels obse:^^ed at most wells. Based on the data available, it is concluded that a signifi- cant potential for the development of ground water for irrigation use exists in portions of all groiond water basins investigated. Water in qiiantities sufficient for stock or domestic purposes can be developed in almost all areas. To determine the potential in a particular basin, reference should be made to the discussion of the basin in question in Chapter IV. Development of ground water resources can, and probably will, proceed through the efforts of individual water users to improve their supplies. This bulletin indicates the ground water potential to guide such development within the areas investigated. However, it should be noted that geologic conditions and the attendant potential for ground water in these areas are highly variable. When considering placement of an individual well, particular attention should be given to the geologic formations which the well would penetrate. The import Division 6, of the Water Code, which expresses the policy that the people of the State have a primary interest in the protection and preser- vation of OTJir ground water basins. -22^4- APPENDIX A DEFINITIONS A-1 EEFINITIONS Andesite A volcanic rock, frequently porphyrltic, varying in color from dark gray to reddish, suad containing plagio- clase feldspar and mafic minerals such as pyroxene, hornblende, and blotite. Andesite often occxjrs as lava flows or plijgs. Anticline An upward fold in stratified materials. Aquiclude Aquifer Aquifxige Basalt A geologic formation or zone >diich, although porous and capable of absorbing water slowly, will not transmit it rapidly enough to furnish an appreciable supply for wells or springs. A bed of clay is a typical aqulclude. A geologic formation or zone sufficiently permeable to yield an appreciable supply of water to wells or springs. A bed of sand and gravel is a typicel aqiiifer. A solid, impermeable mass of rock that contains no water. Noi3weathered granitic rock is a typical eiqviifuge. The most common lava of flows. A dark gray to bleick rock ccHnposed principally of plagioclase feldspar and mafic minerals such eus hornblende or pyroxene, with or without olivine. Confined Aquifer An aquifer overlain by an aqulclude. Conglomerate A consolidated sedimentary rock composed of rounded pebbles and cobbles contained in a matrix of finer material. A-3 Diatomite Diorite Extrusive Igneoxis Rock Formation GoiJge Granite A deposit composed of microscopic shells of plants called diatoms. A moderately dark intrusive igneous rock of granitic texture, composed principally of plagioclase feldspar and hornblende, biotite, or other mafic minerals. Diorite is generally darker in color than granite. A rock poured out on the ground svtrface as from a volcanic vent — a lava. Extrusive igneous rocks axe fine grained to porphyritic and include andesite and basalt. A fairly widespread group of rocks havijag characteristics or origin, a^e, and coniposition sufficiently distinctive to differentiate the group from other \jnits. The formation is the fundamental geologic unit. A layer of soft, fine material occurring between the two walls of a fault, formed as a result of grinding movement. A light colored intrusive igneous rock containing quartz, feldspar, and a small percentage of dark minerals such as biotite and hornblende. Granodiorite A common intrusive igneous rock of granitic texture, intermediate in color and mineral composition between granite and diorite. Ground Water Substurface water occurring in the zone of saturation and moving under control of the water table slope or piezcmetric gradient . k-k Igneotts Rock One of the three principal rock types. Igneovis rocks are ffii formed as the restilt of solidification of molten rock. When the rock solidifies below ground surface, it is called "intrusive igneous." When it solidifies above the ground surface, as a lava, it is called "extrusive igneous." Common igneous rocks include basaJ-t and granodiorite. Intrusive Igneous Rock Joint A rock that solidified beneath the surface of the earth. Instrusive igneous rocks €ire generally coarsely crystalline and include diorite, granite, and granodiorite. A fracture or parting in a rock mass along \rtiich no appreciable movement has occurred. Lava Molten rock such as that which issues fraa a volcano or fissure, also such rock solidified. Most lava is of bjisaltic composition. Molten rock material within the earth, commonly generated at considerable depth. Member A subunit of a formation. Metamorphic Rock One of the three principeuL rock types. Metamorphic rocks are those which have been transformed under conditions of extreme heat smd/or pressure from a sedimenteury or igneoiis rock into an entirely different type of rock. Ccxmnon metamorphic rocks include slate (metamorphosed shale), quart zlte (metamorphosed sandstone), and meta- volcanic rocks (metamorphosed volcanics). A-5 Mudflow Obsidian Permeability Piezometric Siorface Porphyrltlc A flow of debris vhich is lubricated with a large amount of water; also such material solidified. Volcanic glsuss. Although entirely different in appearance, obsidian has similar chemical composition to granite. The mesisure of the rate of movement of gro\md water through natural materials. An imagineury svirface that everywhere coincides with the head of confined ground water in an aquifer. It is represented by the elevation to which water will rise in wells drilled into the eujuifer. The solidified cone of igneovis rock in the throat of an old volcano. Sometimes applied to other dome-like masses of igneous rock. A texture of igneous rocks in ^Ich larger crystals occur in a finer groimdmass. Pyroclastlc Rock A rock formed of fragments ejected from a volcano, the fragments now generally cemented together. Pyroclastlc rocks Include volcanic sish, tuff, tuff breccia, and scoria. Quart zite Rhyollte Rock Flour A granular metamorphlc rock composed essentially of quartz. It is generally a metamorphosed sandstone. A light -colored, fine-grained, igneous rock, often porphyrltlc; mineralogically similar to granite. Finely ground rock peurtioles resvilting from glacial abrasion. A-6 Scoria Volcanic slag; smeiller scoria are volcsuiic cinders. Sedimentary Rocks One of the three principal rock types. Sedimentary rocks are the result of cementation, consolidation, and hardening of clays, silts, sands, and gravels. Common sedimentary rocks incliide shale, seindstone, and conglomerate, Shale Sill A stratified rock, finely bedded or laminated, and formed by the consolidation of clay, mud, or silt. A relatively thin body of igneous rock of nearly uniform thickness ^^ich has been emplaced between two fomerly adjacent strata. Slate The moderately metamorphosed equivalent of shale. Syncline A downfold in stratified rock in which the beds dip toward a central axis. Tuff A rock formed from conrpacted volcanic ash. Tuff Breccia A rock formed of angular blocks of volcanic material con- tained in a matrix of tuff. Vesicular Volcemic Neck Water Table Containing many small openings (vesicles). Vesicular basalt is the aresult of the solidification of a lava charged with geis. The solidified lava filling the vent of a dead volcano. The svirface of ground water at atmospheric pressure in an unconf ined aquifer, as shown by the level at which water stands in a well penetrating the unconf ined aquifer. A-T Welded Tuff A tuff which has been hardened into lava-like rock by the action of heat at the time of ejection and deposition. A-8 APPENDIX B BIBLIOGRAPHY B-1 BIBLIOGRAPHY General References^/ Aune, Q. A. "Reconnaissance Geology of the Northeastern and Eastern Portions of the Alturas Sheet, Ceaifornia." California Division of Mines. Unpublished. I957-58. Geologic maps at a scale of 1:62,500. Includes portions of Alturas, Siirprise, and Madeline Plains ground water hasins. , and Gay, T. E., Jr. "Reconnaissance Geology of the Southeastern Portion of the Alturas Sheet, California." California Division of Mines. Unpublished. 1957- 58. Geologic maps at a scale of 1:62,500. Blackwelder, E. "The Great Basin, With Emphasis on Glacial and Postglacial Times. Part I: Geological Backgroimd." Bxilletin of University of Utah, Vol. 38, No. 20. June 19^8. General geologic background of the Great Basin, including Surprise Valley, Madeline Plains, and Honey Lake Valley. California Division of Mines. "Geologic Guidebook Along Highway ^9 — Sierran Gold Belt." Bulletin No. 1^4-1. 19J+8. Geologic maps at a scale of 1:125,000. Brief description of the geology along Highway h'^. . "Geologic Map of California, Alturas Sheet." I958. Geologic map at a scale of 1:250,000. Includes Goose Lake Valley, Surprise Valley, Alturas Basin, Big Valley, Round Valley, and parts of Madeline Plains and Fall River Valley. . "Geology of Northeastern California." Mineral Information Service. Vol. 12, No. 6. June I959. Brief description of the geology of northeastern California. . "Geologic Map of California, Westwood Sheet." i960. Geologic map at a scale of 1:250,000. Includes Honey Lake Valley, Willow Creek VaJ-ley, Secret Valley, and parts of Madeline Plains and Fall River Valley. 1/ References used for each valley are listed alphabetically by valley following this section. B-3 California State Department of Water Resources. "Northeastern Counties Investigation." Bulletin No. 58. Jwae 196O. A comprehensive ajialysis of present and probable ultimate vater needs of the I5 northeastern counties of California. California State Water Resources Board. "Water Resources of California." Bulletin No. 1. I95I. A concise compilation of data on precipitation, runoff, flood frequencies, and quality of water throughout the State . . "Water Utilization and Requirements of California." Bulletin No. 2. June 1955. Gives the present -use of water throughout the State for all consumptive purposes ajid forecasts of ultimate water requirements based in general on the capabilities of the land to support further balanced development. . "The California Water Plan." Biolletin No. 3. May 1957. A comprehensive master plaji for the control, protection, conservation, distribution and utilization of the waters of California. California State Water Pollution Control Board. "Water Quality Criteria." 1952. A summary of the technical and legal aspects of water quality criteria pertaining to the various beneficial uses of water. Gay, T. E., Jr. "Reconnaissance Geology of the Northeastern Portion of the Westwood Sheet." California Division of Mines. Unpublished. 1959. Geologic maps at a scale of 1:62,500. , and Aune, Q. A. "Reconnaissance Geology of Portions of the Western Half of the ALturas Sheet, California." California Division of Mines. Unpublished. 1957-58. Geologic maps at a scale of 1:62,500. , and Lyden, P. "Reconnaissance Geology of Portions of the West Half of the V^estwood Sheet, California." California Division of Mines. Unpublished. I959-6O. Geologic maps at a scale of 1:62,500. B-4 Hubbs, C. L. and Miller, R. R. "The Great Basin, With Emphasis on Glacial and Postglacial Times. Part II: The Zoological Evidence." Bulletin of University of Utah. Vol. 38, No. 20. June l^hQ. Describes the lakes that once occupied Surprise Valley, Madeline Plains, and other valleys, and describes the fish life once present in them. I-^sson, P. H. "Circular Soil Structiires in Northeastern California" in "Geology of the Macdoel Quadrangle." California Division of I-Iines, Bulletin No. I5I. 19^9- Describes unusual soil structures similar to those found in Big Valley. Meinzer, 0. E. "Itops of the Pleistocene Lakes of the Basin- and- Range Province ajid Its Significance." Bulletin of Geological Society of America. Vol. 33. September 1922. Presents maps showing the extent of the large laJces which once occupied Surprise Valley, Madeline Plains, Honey Lake Valley, and other valleys. . "Outline of Ground-Water Hydrology." United States Geological Survey, Water Supply Paper 49'4-. 1923. Defines various terms lised in ground water hydrology. "Large Springs in the United States." United States Geological Survey. Water Supply Paper 557. I927. Describes and presents data on majiy large springs, including those occurring in Fall River Valley. Ross, C. S. and Smith, R. L. "Ash-Flow Tuffs: Their Origin, Geologic Relations, and Identification." United States Geological Survey. Professional Paper 366. 1961. Describes the origin of ash-flow tuffs similar to the Warm Springs tuff found in the Alturas Basin. Russel, R. J. "Basin Range Structure and Stratigraphy of the Warner Range, Northeastern California." University of California. Publications in Geological Sciences. Vol. 17, No. 11. I928. Geologic map at a scale of 1:125,000. Geologic formations and structure of the Warner Mountains. Smith, R. L. "Ash Flows." Bulletin of the Geological Society of America. Vol. 71, No. 6. June I96O. Describes the origin of ash flows similar to the Warm Springs tuff found in the Alturas Basin. .B-5 . "Zones and Zonal Variations in Welded Ash Flows." Ifeited States Geological Survey. Professional Paper 35^-F. I960. IMited States Department of Agriculture, Soil and Water Conservation Research Branch, Agricultural Research Service, Washington, D.C. "Diagnosis and Ijnprovement of Saline and Alkali Soils." Agriculture Handbook No. 60. Febrxiary 195^. Describes the origin and properties of saline and alkaline soils and discusses irrigation water quality. Waring, G. A. "Springs of California." United States Geological Svirvey, Water Supply Paper 338. I915. Describes and tabulates data for springs, including many found in northeastern California. . "Thermal Springs in the IMited States." United States Geological Survey, Water Supply Paper 679-B. 1935. Describes hot springs, including many found in northeastern California. White, D. E. "Ohermal Waters of Volcanic Origin." Bulletin of the Geologi- cal Society of America. Vol. 68, No. 12. December 1957. Discijsses the chemistry and nature of various types of thermal waters occttrring at hot springs. "Magmatic, Connate, and Metamorphic Waters." Bulletin of the Geologi- cal Society of America. Vol. 68, No. 12. December 1957. Discusses the chemistry of variovis types of spring waters. Alturas Basin California State Department of Public Works, Division of Water Resources. "South Fork of Pit River Court Reference Report on Water Supply and Use of Water on South Fork of Pit River and 'Tributaries." Madoc and Lassen Counties, California. January 1933. Court reference report. Briefly describes the watersheds, climate, and crops in the area of South Fork Pit River. . "North Fork of Pit River Adjudication Report on Water Supply and Use of Water on North Fork of Pit River and Tributaries." Modoc Coimty, California. Augrist 1937. Treatment similar to above, but for North Fork Pit River. B-6 California State Department of Water Resources. "Water Quality Investiga- tion - Altvcras and Wann Springs Valley Basins." Unpublished, i960. Detailed results of a water qviality investigation of the Alturas Basin. Carpenter, E. J. and Storie, R. E. "Soil Svarvey of the Alturas Area, California." Itoited States Department of Agriculture, Bureau of Chemistry and Soils, Series I93I, No. 23. 1936. Presents a soils map of the Alturas Basin (scale, 1:63, 36o) and a discussion of the soil types found. Ford, R. S. "Ground Water Geology of the Alturas Basin, Modoc County, California." CeLlifornia State Department of Water Resources. IMpub- lished. 1962. Russell, R. J. "Landslide Lakes of the Northwestern Great Basin." IMiver- sity of California Publications in Geography. Vol. 2, No. 7. 192?. Describes the lake that once occupied Jess Valley. Big Valley and Roxmd Valley California State Department of Public Works, Division of Water Resources. "Pit River in Big Valley Adjudication Report on Water Supply and Use of Water on Pit River Stream System in Big Valley." Modoc eind Lassen Counties, California. May 1956. Court reference reiKjrt. Briefly describes the watersheds, climate, and crops on Pit River System in Big Valley. California State Department of Water Resoxjrces. "Water Quality Investigation - Big Valley." Ifepublished, 1959. Detailed 3?esxilts of a water quality investigation of Big Valley and Roimd Valley. . "Upper Pit River Investigation." Bulletin No. 86. November I960. Presents plans for development of the water resources of Big Valley. Hail, W. R. "Ground Water Geology of Big Valley and Round Valley, Lassen and Modoc Counties, California." California State Department of Water Resources. IMpublished. I962. Scott, D. P. "Engineering Geology of Allen Camp Dam Site on the Pit River and Round VsuLley Dam Site on Ash Creek, Modoc County." California State Department of Water Reso\jrces. lAipublished. July 1958 • B-7 Watson, E. B. and Cosby, S. W. "Soil Survey of Big Valley, California." United States Department of Agriciiltixre, Btireau of Soils. Series 1920-24. Soils map of Big Valley at a scale of 1: 63,360. Disciosses soil types found in the valley. Fall River Valley Anderson, C. A. "Volcanoes of the Medicine Lake Highlands, California." Lftiiversity of Califoraia, Bulletin of the Department of Geological Sciences. Vol. 25, Ifo. ?. 19^1. Crlgon and geology of the Medicine Lake Highlands area. "Hat Creek Lava Flow." American Journal of Science. Vol. 238, No. 7« 1950. Origin and geology of the Hat Creek lava flow. California State Department of Water Resources. "Shasta County Investiga- tion." Bulletin No. 22. December i960. Basic data relating to siirface and ground water of Shasta County, including Fall River Valley. . "Water Quality Investigation - Fall River Valley." IMpublished. I96O. Detailed results of a water quality investigation of Fall River Valley. Swanson, A. A. "Ground Water Geology of Fall River Valley, Shasta and Lassen Coimties, California." California State Department of Water Resources. Unpublished. I962. Goose Lake Valley Baldwin, E. M. "Geology of Oregon." University of Oregon. 1959* General geology of the Oregon portion of Goose Lake Valley. California State Department of Public Works, Division of Water Resources. "New Pine Creek Court Reference Report on Water Supply and Use of Water on New Pine Creek." Modoc County, California. Febrtiary 1932. Court reference rejKDrt. Briefly describes the history, watershed, climate, and crops in the area of New Pine Creek. B-8 . "Cottonwood Creek Court Reference Report on Water Supply and Use of Water on Cottonwood Creek." Modoc County, California. March 1933. Treatment similar to above, but for Cottonvood Creek. California State Department of Public Works, Division of Water Rights. "Davis Creek Court Reference Report on Water Supply ajid Use of Water from Davis Creek." Modoc County, California. January I929. Treatment similar to above, but for Davis Creek. California State Department of Water Resources. "Water Qiiality Investigation - Ctoose Lake Valley." Uipublished. 1959. Detailed results of a water queuLity investigation of California portion of Goose Lake Valley. Carpenter, E. J. and Storie, R. E. "Soil Survey of the Alturas Area, California." Iftiited States Department of Agriculture, Bureau of Chemistry and Soils. Series 1931, No. 23. I936. Soils map of the California portion of Goose Lake Vailley (scale 1:63,360). Discusses the soil types found in that portion of the valley. Ford, R. S. "Ground Water Geology of Goose Lake Valley, Modoc County, California." California State Department of Water Resources. Iftipublished. I962. Peterson, N. V. "Preliminary Geology of the Lakeview Uranium Area, Oregon." The Ore -Bin. Oregon State Department of Geology aiid Mineral Industries. Vol. 21, No. 2. February 1959. Brief geologic description of an area on the west side of the Oregon portion of Goose Lake Valley. Trauger, F. D. "Beisic Ground-Water Data in Lake County, Oregon." Ifaiited States Geological Survey. October 1950. Presents tables showing well data, well logs, and ground water analyses for the Oregon ixjrtion of Goose Lake Valley. Honey Lake Valley Ceilifornia State Department of Public Works, Division of Water Resources. "Susan River Coiort Reference Report on Water Supply and Use of Water on Susan River and Tributaries." Lassen County, California. February 1936. Court reference report. Briefly describes the history, watershed, climate, and crops in the area of Susan River. B-9 . "Baxter Creek Adjudication Report on Water Supply and Use of Water on Baxter Creek Stream System." Lassen County, California. April 1952. Treatment similar to above, "but for Baxter Creek. California State Department of Water Resources. "Water Quality Investigation - Honey Lake and Willov Creek Valleys." IMpublished. I960. Detailed results of a water quality investigation of California portion of Honey Lake Valley. Gay, T. E., Jr. "Reconnaissance Geology of the Doyle, Litchfield, Milford, and Wendel Quadrangles and the Northern Portion of the Susanville Quadrangle." California Division of Mines. Unpublished. I960. Ifcpublished geologic maps at a scale of 1:62,500. Guernsey, J. E., Joeber, J., Zinn, D. J., and Echmann, E. C. "Soil Survey of the Honey Lake Area, California." IMited States Department of Agriciilture, Bureau of Soils. 1917 • Soils map of the California portion of Honey Lake Valley. Describes the soil types found in that portion of the valley. Hail, W. R. "Ground Water Geology of Honey Lake Valley, Lassen County, California." California State Department of Water Resoinrces. Unpublished. 1962. Hilton, G. S. United States Geological Survey, prepared in cooperation with United States Department of the Army. "Water Resources Reconnaissance in Southeastern Part of Honey Lake Valley, Lassen County, California." Sacramento, California. I960. Brief appraisal of the groxmd water resources of the Sierra Ordnance Depot. Lydon, P. A. "Reconnaissance Geology of the Southern Portion of the Susanville Quadrangle." California Division of Mines. Iftipublished. i960. Unpublished geologic map at a scale of 1:62,500. Peterson, N. V. "Prospective Stock-Well Sites in Honey Lake Grazing District, a Few Miles East of Susanville, California, and in the Cal-Neva lfa.it Near Flanigan, Nevada." Uiited States Geological Survey. Ifiipublished. 1953. Describes the geology as related to groimd water in the two areas investigated. Russel, I. C. "Geological History of Lake Lahontan, A Quaternary Lake of Northwestern Nevada." United States Geological Sxorvey Monograph XI. 1885. Describes Lake Lahontan and its effects on Honey Lake Valley. B-10 Stinson, M. "Reconnaissance Geology of the Northern Portion of the Chilcoot Quadrangle." Csilifornia Division of Mines. Unpublished. 1959. IMpublished geologic map at a scale of 1:62,500. Madeline Plains California State Department of Public Works, Division of Water Resources. "Madeline Plains Drainage Basin Reconnaissance, Lassen County." Water Q\iality Investigation Report. July 1953* A preliminary report on the qviality of groxmd water in Madeline Plains. California State Department of Water Resources. "Water Quality Investiga- tion - Madeline Plains." Unpublished. 1959. Detailed results of a water quality investigation of Madeline Plains, Dry VaU.ey, and Grasshopper Valley, Iwamura, T. I. "Ground Water Geology of Madeline Plains, Lassen County, California." California State Department of Water Resources. Unpublished. I962. King, N. J. "Development of Stock-Water Resources in Madeline Plains." Halted States Geological Survey. Ifapublished. Not dated. A brief account of the geology and its relationship to stock-water well development. Sierra, Mohawk, and Humbvig Valleys CaJ-ifornia State Department of Water Resources. "Water Quality Investiga- tion - Sierra and Mohawk Valleys." Unpublished. I960. Detailed results of a water quality investigation of Sierra and Mohawk Valleys. Durrell, C. "Geology of the Blair sden Quadrangle." University of California at Los Angeles. Unpublished. 1952. Geologic map at scale of 1:62,500. "Tertiary Stratigraphy of the Blairsden Quadrangle, Plumas Cotuity, California." University of California, Publications in Geologicea Sciences. Vol. 3^, No. 3- 1959. "The Love joy Formation of Northern California." University of California, Publications in Geological Sciences. Vol. 3^, No, ^t-. 1959. Describes the occurrence and characteristics of an Eocene basalt flow in Blairsden quadrangle. B-n Ford, R. S. "Groiind Water Geology of Sierra, Mohawk, and Himibug Veilleys, Plumsis and Sierra Counties, California." California State Department of Water Resources. Iftiputlished. I962. Hail, W. R. "Engineering Geology of the Frenchman Dam Site on Little Last Chance Creek, Plxanas Coionty. " California State Department of Water Reso\arces. IMpublished. 1957' Kresse, F. C. "Engineering Geology of Sheep Canrp Project on Carman Creek, Sierra and Plumas Counties." California State Department of Water ResQurces. Unpublished. 1958. . "Summary Engineering Geology Report, Randolph Dam Site on Cold Stream, Sierra County." California State Department of Water Resources. Unpublished. 1958. "Geologic Reconnaissance of Clover Valley and Sattley Dam Sites." California State Department of Water Resources. IMpublished. August 1958. Lindgren, W. "Description of the Gold Belt; Description of the Truckee Quadrangle." United States Geological Stirvey. Folio 39. I897. Describes the geology and presents a geologic map of the Truckee quadrangle at a scale of 1:125,000. Sprinkel, R. L. "A Report on Geology in the Vicinity of Portola, Pliimas County, California, With Reference to an Underground Water Supply for the Western Pacific Railroad Company." Lfapublished. 1936. Discusses the groimd water development possibilities in the Portola area. Stinson, M. "Reconnaissance Geology of the Portola, Chilcoot, Sierraville, and Loyalton Quadrangles." California Division of Mines. Unpublished. 1959. Geologic maps at a scale of 1:62,500. Turner, H. W. "Mohawk Iiake Beds." Philosophical Society of Washington. Vol. 11, 1892. Describes the lake deposits in Mohawk Valley. "Description of the Gold Belt; Description of the Dovnieville Quad- rangle." Itoited States Geological Survey. Folio 37. I896. Describes the geology and presents a geologic map of the Dovnieville quadrangle at a scale of 1:125,000. B-12 S\irprlse Valley California State Department of Public Works, Division of Water Itesources. "Pine Creek Court Reference Report on Water Supply and Use of Water on Pine Creek in Surprise Valley." Modoc County, California. March 1933. Describes history, watershed, climate and crops of Pine Creek area. . "Rader Creek Court Reference Report on Water Supply and Use of Water on Rader Creek." Modoc County, California. December 1935* Treatment similar to above, but for Rader Creek. "Bidwell Creek Adjudication Rejxjrt on Water Supply and Use of Water on Bidwell Creek Stream System." Modoc County, California. March I956. Treatment similar to above, but for Bidwell Creek. California State Department of Public Works, Division of Water Rights. "Owl Creek Court Reference Report on Water Supply and Use of Water from Owl Creek." Modoc Coimty, California. December 21, I925. Treatment similar to above, but for Owl Creek.. . "Emerson Creek Court Reference Report on Water Supply and Use of Water from Emerson Creek." Modoc Coimty, California. December J, I927. Treatment similar to above, but for Emerson Creek. California State Department of Water Resources. "Water Quality Investigation Sirrprise Valley." Unpublished. I960. Detailed description of a water quality investigation of the California portion of Surprise Valley. Carpenter, E. J. and Storie, R. E. "Soil Survey of the Alturas Area, California." United States Department of Agriculture, Bureau of Chemistry and Soils, Series 1931, No. 23. I93I. Soils map of the California portion of Surprise Valley (scale 1:63,360). Discusses the soil types found in that portion of the valley. Iwamura, T. I. "Ground Water Geology of Surprise Valley, Modoc and Lassen Coxmties, California." California State Department of Water Resources. IMpublished. I962. La Motte, R. S. "Ttxe Upper CedarviUe Flora of Northwestern Nevada and Adjacent California." Carnegie Institute of Washington. Publication 1^55. 1936. Describes the forests and climate of the Surprise Valley area during the Miocene epoch. B-13 Russell, R. J. "The Land Forms of Siorprise Valley, Northvrestern Great Basin." University of California Publications in Geography, Vol. 2, No. 11. 1927. Geographic features in and around Surprise Valley. Snyder, C. T. "Prospects for Stock V/ater Development in the Massacre Lake Grazing Area, Washoe Co\inty, Nevada." United States Geological Suirvey, Water Resources Division. Unpublished. September 1951- Geologj^' and ground water features of the Nevada portion of Surprise Valley and also of other valleys in V/ashoe County. White, D. E. "Violent Mud- Volcano Eruption of Lake City Hot Springs, Northeastern California." Bulletin of the Geological Society of America. Vol. (£>. September 1955- Describes the mud- volcano eruption of I4arch 1951- B-l4 Id' 21 '11 m AU 381786 TC82U Calif. Dept. of Water C2 Resources. A.2 Bulletin. no. 98 v.l PHYSICAL SCIENCES LIBRARY 3 1175 00464 9375 LIBRARY UNIVERSITY OF CALIFORNIA DAVIS r«»p'''SS?SSSST^S3 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW BOOKS REQUESTED BY ANOTHER BORROWER ARE SUBJECT TO IMMEDIATE RECALL RECEIVED FEB 2 2 1996 PHYSICAL 3CS. LIBRARY LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS D4613 (7/92)M I