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Photographic

Sciences
Corporation

2i WEST MAIN STREET

WEBSTER, N.Y. 14580

(716) 873-4503

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REFERENCE/CONSULTATION

Not to be taken from tne Library.

Get ouvrage ne peut etre consuUe qu'^

la Biblioth6que.

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XHorTnas C PC^efe^r, C. Ixl, O., O. E.

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jPlI tHe; CiT.a.tJ.d.ie;re;

OTTAWA

1895

■;^31!:A»af J?;,.s,;W'"' i^iS^^i'>M"*"-h:: -.'Jtiit^j f mEIWW. .vt.mMm>m. tm

-^.mt*«3Tr'»

THE OTTAWA ELECTRIC COMPANY.

CiKNTl.KMEN, — In compliance with your verbal instructions of jtli March
last, I examined, as long as the ire permitted, the section of the Ottawa
River above the Chaudiere Falls, as far up as Thompson's Bay, which sec-
tion includes the first two rapids above the Chaudiere, and all the open
uatir in winter above and below them. This examination was made with
the view of ascertaining what remedy, if any, can be resorted to in order
to prevent interruption to, or diminution of, the winter water power by
the anchor ice, which gave so much trouble here in February and March
last.

The conditions were favorable for such an examination, as it was the
close of a severe low water winter, during which the maximum quantity
of arvchor ice had accumulated, and had. in consequence of low water and
thickness of surface ice, produced its maximum effects, because of the
reduced size of the winter waterways, and the increased current through
these caused by the draught toward the wheels, bringing along with tlie
water more anchor ice than usual.

Owing to the late date at which this survey was commenced, and liic
probability that the ice might move at any time, nothing like a complete
exploration of the conditions under the ice could be attempted over so
large an area. Trial lines of soundings were, therefore, first made from
the most promising points in Nepean Bay, on the Ontario or south side of
the river, in order to discover where the anchor ice was collected, and
where there were channels more or less free for the passage of the limited
and insufficient amount of water which reached the slide channel and the
mill races between it and the Chaudiere Falls. While the ice remained,
these soundings were extended so as to give a general knowledge of what
was going on under the ice, but could not be multiplied so as to make a
chart accurate enough to determine the size of channels or extent of
shoals, for the purpose of estimating the amount of work required to en-
large the one or to remove the other, should it be found practicable to do
so with reasonable outlay. ,

The survey also embraced the position of the surface ice. and the
patches of open water within the limits examined, in order to show from
how large an area the formation of anchor ice was derived. This ice is
entirely the product of water exposed to the air in winter, and never forms
where and after the surface is covered or frozen over. Had there been
mre open water immediately above the city in such a winter as the last,
the result to the water power might have been more serious ; while, on the
other hand, during a mild and high water winter, there would have been
more open water with much less anchor ice. and no interruption to the
water power at present established at the Chaudiere.

The examination was not extended beyond the open water below
Thompson's Bay, because there is no reason to suppose that any anchor
ice passes that bay from the Deschenes Rapids. None can be formed in
this section of the river after the surface is frozen over, and there is not
strength of current enough in this wide and deep section to carry anchor
ice from the Deschenes Rapids (where alone it could be formed) through
its length of nearly two miles under the surface ice. which always retards
and arrests it in slack water.

31519.

UI'.SI'KIPTION.

lU'lWfon till' Crtat and tlic Ijtik- Cliandicn- ( wliiili aic ics^ than mif
mill- apart), tlu- main body uf \\a- water of the Ottawa Kivrr ll(iu> in a
very (lircrt lino aloiifj; tlic luirtli shore. The soiitli or O.aario shore htu'
eiirvcs inland from hoth the Chamhire^. fornnnn Wpean Kaj. uliuh emi
taitis in its npper |>.irt ahoiit twenty islands, the lower one of wineh.
lycmienx Islaml. is nmeh the largest of all, and is crossed on its down
stream end hy the Canadian I'acilic Railway. Xepean liay receives fioin
aI)ove and !)elow I<eniien.\ Island. On the south side it draws from ihe
deep pool helow the " Mast Channel " of tiie l.itlle Chauiliere, hy four
narrow channels, one of which is dry at low water. The southern-most of
these, hetween the south shore and Fury island (just helow ihe site of the
old Sparks null), is ahout 173 feet wide at low water, with depths of 10,
15, JJ, ^6, 17 and o feet, t.'du'ii at intervals of twenty live fe.i, s^artiii;.;
fr tin tin south slujre. Tliis is the largest of the feeders of Neptiiii li v
above Lemieux Island. The next in onkr, from the south, is the lii.'ii
water channel, only .^(j to .jo ivci in width, hetweeii Fury and Xicliola^
Islands; the third, hetweeii Nicholas and Merrill Islands, is ahout 75 reel
wide, with only 5 to 7 feel water; tile fourth, lietweeii Merrill and Vciunii s
Islands, is the second in importance, and is 15,0 feet wide, with depths ' f
3, 21. 21, 12 ami 4 feet, taken as ahove. Young's li-land is coniuel^d willi
Lemieux Island hy dams for log-running puiposi's. 1 liese four ciiaune -
arc collected lower down into one, hetweeii iyiinieux and the mainland
above Mas(jn's mill, which oi:e is ahout 500 feet wide, only ahout 100 fevt
of which has 10 to u feel of water, the remaining 400 feet lia\ ing .■; fev t
and under. The main channel of the Ott;iwa, on the oilier side of l,eiiiieu.\
Island, is one thousand feet in width, wiili an a\eiage deinh of J.i feet.
Nei)ean Bay can only draw from this norlli channel, over ;i wide expanse
of shoal (between Lemieux and Russell Islaiuls), inside of which there
are deeper channels, the usefulness of which is limited hy tlie shoakr
water at the entrances.

The whole Ontario side of the river l)ed is a suhmerpcd rocky plateau.
lying 10 to .30 feet or more at)ove the hottoin of the norlh shore or m.iiii
channel above the Great Chaudiere. If this section of the river surface
were lowered 10 feet below lowest water, it would be possible to walk dry
shod from the south shore aliove the railway bridge to Lemieux Island.
and thence to the Big Kettle via liussell Island. The greater portion of
the southern half of the river bed would, under this condition, be dry;
while there was yet deep water in all the north channel, from the Little
Chaudiere to the crest of the falls. From these conditions of the river
bed on the south side, it is evident that the existing channels arc insuffi-
cient to give Ontario the proportion of the river at low water to wliich sh''
is entitled, and sooner or later the question of the partition of this water
must be dealt with.

When the three small low water channels described, at the head of
Lemieux Island, arc closed, as was the case last winter (except as to the
first, which was more than half closed), Nejiean Hay beccjmes entirely
dependent for a supply upon the opening between it and the main or north
channel below the railway bridge. We fouiifl the lower or down stream
half of the opening between Lemieux or Russell Islands closed by anchor
i£e .which probably took place after the level in Nepean Bay fell from
the cutting ofT of a supply on the south shore. This lowering of the level
on the south shore would give a strong draught from the north cliaincl.
which would bring in anchor ice from that channel which otherwise would
have gone into the Big Kettle. On the 5th of February last, the City
Engineer found the level in the north channel near the C. P. R. bridge 2'/'.
feet higher than the level in Nejiean Bay. at the mouth of the aqueduct.
On the i8th March I found the difTercnce of level less than half of this.

•^f^^

<> than (itic
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of wliicli.
I 11'^ < low II
fives from
■* fnnii ihc
I'. Iiy four
rii-iiiost of

>iti' (tf tlu'
l)llis c)l 10.
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! .\'n.-!:i)la>
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vClLil with
r ciKiinu- -

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It 100 fr.l
iiiK 3 ft.'i t

f Kl'llllCUX

c c\])ansf
lioli tluTC
ic shoakr

y plateau,
c or main
T suifacr

walk dry
IX I.slancl.
)ortion of
. be dry ;
the Little

the river
re insuffi-
A'liich she
liis water

: head of
as to the
? entirely

or north
n stream
ty anchor
fell from

the level

clian'iel,
so would

the City
ridpe 2'/'!
iqucduct.
3f this.

1
f

The upper half of tliis opeiiiuK Itetweeii I.mni n\ and Rl1^^^■ll Ulaiid.-
was ivideinly the eliit f and alniM>i ilir only >(>uree fmni whieh Xi|)eaii jtay
was fed after l>t I'\hrnaiy. lUiUK under the lee of l.einieux Uland. tlu'
pa>suiK ice emild iidt work haek iiuo it so IdUK as there was a sinm^'er
diaUKht heliiw. Tlie same eoiiditinii existed in the sdulherninosi channel
at the (lid Siiarks null site. The Hidy water enti-rin^; the south chamiel
wa> next to Hie shore, the wider ami dee|)er portion fmilur out heiiix
filled wiili anchor ice.

PIP1-: CI1.\NXI'I..

Inside the bar which stretches from the ivnth side of i.emieux to
Ku^sfii Island, there is a channel, or rather dei)ression. crossin(( tin.' river
nearly at riijtlit aufrles, which ha«. hren taken ailvantaiie of hy the city in
order to get the i)ure water pipe drip eiioUKh to he lieyoud tlie rtaeli of
the '-urface ice. 'I'his depression, which extends into the deep water of
Nepean I5ay al)o\e the atineduet (hut not into ili.it (<f the iiorll'. channel),
may not he a summer feeder of N'epian l»ay. it was prohahly on this
account not c;illed into re(|uisitioii t(. any extent until the south ch.iuuel
was closed, and the level in Nei)eaii liay fill so as to draw heavily upon it.
It is al-o prwbal-le that llere wa^ not enough of anchor ice inanufaetnred
after this took ]dace to encroach upon this passage to a greater extent than
it did before .April.

Mr. J.ames Mark<, boom kei])er in Nepean Hay in 1872, informed me
then that the anchor ice from tlie Little Chajidiere which came down the
south shore was stopped hy a ret.f about midway between the two Chau-
dicres. and that when this takes place N'epeau liay is supplied by the chan-
nel ontside the islands (ihat is, the north channel), a channel wdiich, he
says, never briiiRs in anchor ice. This reef in the south chamiel is .ahove
and ne.ar the railway hridpe, and almost all the anchor ice found in the
south channel this year was above this bridRe.

The river bed covered by the waters of Nepean I'.ay has a very irre-
gular bottom, made up of pools and shoals. The deepest of the pools is
that which bey;ins above the aiiueduct and extends down stream beyond
the slide channel. It runs close to the shore at the railway yatvd, and
carries a width of about 500 feet, between lines of 10 feet w.iiei, ami a
maximum depth of 17 to iS feet, with some holes having 20 feet, the bot-
tom rising rapidly toward the slide and mill channels. I'l) st!e;iiii the
bottom rises so as to i;ive 6 to 8 feet depth at the railway bridge, but he-
f(.ire it reaches this point it strikes the cross river depression in which the
waterworks pipe is laid, and by which route it received nearly the wdiole
of its supply after ist February last. This dei)ression is about l.Soo feet
in l"ngth. At No. ,^ waterworks crib, the wiclth was about 400 feet, be
twecn lines of 8 feet water, the average depth in the centre being alxjiit
ID f^et, ranging from 8 to 12 feet. The waterworks pii)e occupies a por-
tion of the deepest and most effective section of this channel.

The irregularity of the bottom in the southern channel is shown by
low water deptlis of 18 feet at the aqueduct, 8 feet at the railway bridge.
20 feet at 600 feet above the bridge, and 12 feet at a point 300 fiet lii;^her
up.

When the supply for Nepean lUiy was drawn from below Lemieux
Island, the level in this bay was only prevented from falling lower by the
inability of the slide and mill channels to draw it any further down. Had
the entrances to these been as deep as the atjueduct, a level might have
been reached which w'ould have seriously effected the pumping power of
the latter.

r.' i

ANCHOR ICE.

^n order to appreciate the value of proposed methods of deaHng with
anchor ice, it is necessary to consider what it is, where aud why it forms,
and the possibihties in any case of preventing its formation, or of divert-
ing its flow away irom tlie cliannels which supply the water power.

Anchor ice is so called because at certain days of the winter months
(and for a few days or hours at a time) it is found at the bottom of the
open water in streams and rivers where the fall is sufficient to prevent
freezing over at the surface. As long as the temperature is low enough
it remains on the bottom, to which it is cemented by frost, and is thus
anchored there. So long_as it is anchored its only effect is, when in suffi-
cient quantity, to raise the suruice level, by thus raising the bottom, and
by the dams it forms upon shoals in the rapids. It is, therefore, only when
it rises and floats that this deposit niay prove troublesome to water power.

The greater portion, however, of what is called anchor ice is never
anchored. The ice crystals, spicuiae or " needles," which in freezing wea-
ther shoot out ia the surface of quiet water, interlace and soon make a
closed covering, become, when disturbed by the action of wind and cur-
rent, broken up, jumbled together, and form in patches of "slush" ice.
Both kinds differ from solid ice as granulated sugar differs from loaf
sugar, the stirring up by wind and current preventing solidification. An-
chor ice is called " frasil " and " fraisil " by the " habitants " of Quebec,
words meaning water soaked snow and cinder. Its manufacture goes on
in a greater or less degree in the open water in every day of frost, but
when the air temperature is below zero, the broken water is reduced to
the freezing point throughout its depth by its rolling motion in descending
a rapid, by which every portion is brought lo the surface (and in contact
with the cold air, where only ice can be fornied), and again carried to the
bottom. The whole mass is filled with ice crystals, sometimes so thick as
to be felt with an oar or paddle, to which the crystals adhere like filings
to a magnet. The rapid passage of this icy tlood over a stony or rocky
bottom robs it of heat, and induces radiation until this bottom is brought
into a condition to attract the passing crystals and cement them to itself,
and then the growth of true anchor ice commences there. This growth is
immediately arrested by a rise in temperature, and when this is above the
freezing point, this " anchored " ice lets go its hold on the bottom, rises
and floats down the river. It seldom forms to such a depth as to affect
the surface level of large streams, although it does so in brooks during
moderate frosts, but in 1857 the St. Lawrence River above the Lachine
Rapids was raised four feet in one night during the month of January.
Of course this river resumed its normal level as soon as the anchored ice
rose from the bottom, but this same ice in descending the river becomes
the chief factor in causing the winter rise in the St. Lawrence below
Montreal, but by a reverse operation from that which caused the tem-
porary rise above the Lachine Rapids. The moment it reaches the ice
bridge below the city it is drawn under, but immediately rises, skipping
along on the underside of this bridge, until arrested by friction and frost,
when it is anchored to the underside of the surface, and ready to assist in
anchoring a succeeding floe. In this manner anchor ice is suspended from
the underside of the surface ice, in some places as much as 35 feet down-
ward, over a great extent, for ten or twelve miles below ^lontreal, in many
places reaching entirely to the bottom. The effect of these suspended
dams is to set back the river current, causing it to rise and cover the
wharves for the whole winter, and sometimes send ice floods over con-
siderable portions of Montreal.

It is under this secondary condition that anchor K:e invades Nepean
Bay. The " slush " ice which is formed on the surface before the bay is

frozen over is unimportant, as it docs not diminish the channel capacity,
and can l)e arrested and removed before it reaches the wheels, but that
which conies afterward from above the bay after it is frozen over, mucli
of which is true anchor ice. is invisible, and takes up a position which
gradually encroaches upon the waterway, until it threatens wholly to cut
off the supply. This ice comes almost exclusively from the open water
between the foot of the Little Chaudiere rapids and Thompson's Bay,
above the Remiques. Tliat which is formed below the Little Chaudiere
in the north channel is chiefly carried into the Big Kettle, at least until
late in the winter, when, if the south channel is closed by anchor ice, a
suriicient draught may be created toward Nepean Bay to draw in more or
less of that which may be floating along the south side of the north chan-
X nel. The greater part of this ice which comes from above is arrested in

S the deep pool at the foot of the Little Chaudiere by the ice bridge which

forms over it there. It accumulates in the eddy at the foot of the Mast
Channel, and widens out until it is drawn into the channels between the
islands, gradually closing them, and what is not so disposed of is carried
down the main channel, forming similar accumulations in eddies on the
north side, or descending to the Chaudiere Falls. Three of these deposits
were found in this pool in March last, covering from one-quarter to one-
third of an acre each, one opposite the Mast Channel, the other two upon
the north side, resting on the bottom in one case where it is 85 feet deep,
and holding up the surface ice from 2 to 4 feet above the water level. With
every thaw, the whole deposit of anchor ice which has formed in the rapids
of the Little Chaudiere and the Remiques is cleared ofif and sent below,
leaving the open water ready for a new crop. The quantity so manufac-
tured during a long severe winter is enormous, in some winters perhaps
more than double that in others, and the efifect of the quantity on the
water channels is greater or less according to the water level, high water
making more room for the storage of this anchor ice between the surface
ice and the bottom, where (as it does not melt), it remains till the spring.

The submerged dam above the Chaudiere Fall.s has weakened the
original current between the two Chaudieres, and it, together with the
wing dams thrown out by mill owners on both sides of the river, has
caused the wintering of more anchor ice above the Chaudiere Falls than
was held there formerly, when anchor ice came over the falls in such
quantity as to form a iarge deposit in the deep water below the Chaudiere
islands, filbng up the space between the surface ice and the bottom of the
river before the latter had reached its low water level, and holding up the
surface ice, which drooped in every direction, forming a cone-like hum-
mock, to show where the anchor ice was grounded. This is no longer
seen, although there were three similar but smaller ones this winter at the
foot of the Little Chaudiere.

REMEDIES.

There are three ways of seeking relief, only one of which will get rid
of the anchor ice. These are (i) by deepening and enlarging the chan-
nels which supply Nepean Bay, in order to make more room for ice and
water; (2) by raising the winter level of the reach between the two Chau-
dieres to efifect the same purpose, and (3) by getting rid of the anchor
ice forever by a dam across the Ottawa at the Little Chaudiere, which
would raise the water there to the level of Thoinpson's Bay.

The value of the first method would depend upon the scale on which
it was carried out, a sufificient scale, no doubt, costing more than the
second plan, which would produce the same efifect. Its chief merit is that
it is (under present conditions) the only way of securing to the Ontario
side a more equal share of the low water flow. There is the uncertainty
with the first plan, whether in bringing in more water more anchor ice

Mil

may not be brought in with it. but the enlargenu'Ut of the channel reduces
the current and attraction of anclior ice, and nialvcs more room for it if
brought in. It would be most etlicient, of course, in the channels least
exposed to anchor ice as that below L/jmieux island. Unless undertaken
on a large scale, with a view to partition of the low water How, it would
be but temporary relief, and require further enlargement, with the extend-
ed use of the water power supplied from Nepean Hay.

It is possible to get the water without the ice. from a river laden with
floating anchor ice, when the conditions are favorable, as at the mouth of
the Montreal aqueduct above the Lachine Rapids. This i;^ done by form-
ing a basin or harbour with a wide deep entrance, through which the current
is too olight to attract the passing " frasil " from the strong current toward
the rapids. These conditions do not exist here, though it may be prac-
ticable to force the anchor ice at the Little Chaudiere into tlie north chan-
nel, and thus exclude it from the southern one, but this would come so
near to damming the river at this point that it would no doubt be pre-
ferred to adopt the third, which is the best and only certain plan, and dam
the river there entirely.

The conditions for the construction of such a dam (which would be
about the same length and height as the one at Carrillon) are favorable,
rock foundation, ample room for flood overflow, and shores unoccupied
by valuable improvements. It would give about lo feet head. The llow
of the Ottawa at Grenville is given at 35,000 cubic feet per second, and as
this is only about one-tenth of that of the St. Lawrence below Montreal
after its junction with the Ottawa, it seems a fair estimate. If it can be
taken at a little more than two-thirds of this above Ottawa, or 24,000 cubic
feet per second, a dam at the Little Chaudiere would give 2,000 horse
power for every foot of fall, or about 20,000 horse power altogether.

The second plan, of raising the winter level by a moveable dam, would
probably give greater immediate results for the outlay, and would per-
manently increase the value of the water power at the Great Chaudiere,
at the expense of that at the Little Chaudiere. It might not prove suffi-
cient for the future partition of the low water flow between the two sides
of the river, and could only postpone the anchor ice difficulties, which
would revive with extended increase of water power on the Ontario side.

The dam at the Little Chaudiere would create a water power of much
greater value than its cost, would abolish anchor ice. and render the future
partition of low water flow between the two sides of the river a less diffi-
cult question than it now is.

'file plan accompanying this repott is based upon the survey for the
railway bridge in 1870, the soundings for which were taken on the ice in
March, or low water season. Similar soundings below Lemieux Island
would furnish a close estimate of the work required to secure a channel
of desired width and depth between the north and the waterworks pipe
channel — and should be extended on the sides of the latter to the aqueduct
to show the points where widening is needed and practicable.

I have added soundings from Government and City sources to those
taken before, fro 1 which a rough estimate could be made of the amount
of cutting requii d for any scale, but a closer examination of the bottom
at low water sh' aid be made to distinguish the rock from deposits of bark
which exist in these quarters.

I rem.ain, yours,

THOS. C. KEEPER.

Ottawa, July, 1895.

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