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INCORPORATED 1887.
ADVANCE PROOF— (.Subject to revision).

N.Ii.— This ii^ociety, as a body, does riot hold itself responsible for tlip fui lr>
and opinions stated in any of its publications.

PEASER VALLEY: RECLAMATION.

CONSTRUCTION OP TWO SLUICE BOXES AND FLOOD GATES.

To be read Thursday, 8th April, 1897.

Bv II K, P.\LMEB, .\. M Can. Soc. C. E.

Tlic freshets or floods of the Frascr River, British Columbin, occur
as a rule brtween the latter end of May and the middle of July, caused
principally by the melting of the snow upon the niouDtain«.

In the reclamation of portions of the delta lands of this valley, from
these freslicts, the most difficult part of the !-chemcs at present adopted is
the satisfactory design and building of the sluice boxes and food gates.

Up to the presrnt time, that portion of the delta reclaimed lies in
patches, cnch portion being protected by itself, and not connected with
any other portion. Generally these patches or valleys front on the
main river, and arc surrounded on all sides, with the exception of the
frontage, by high binds, which discharge all their drainage upon the
flats. This water finds its way over these flats through sloughs and
creeks which di.eobargc into the n)ain river, during tliu low or ordinary
stage of the water, namely, from August to the end of April.

The sy.stem of rcclamaition adopted up to the present dny has been
that of the construction of dykes or cnibankmints, of difi'erent dimen-
sions, along the banks of the river, from high lands to high lands, and
of the building in the creeks or sloughs, over which the dykes would
pass, of flood gates, :ind sluice boxes as they are culled, which are so
constructed as to clcso during the high water, preventing tlie river
water from .baekiriij up the sloughs au'l flooding the prairies. They
are constructed also u> open, so soon as the water in the river begins to
fall lower than that in the slougli.s, :ind drain the prairies, the slouiilis
during the period when the giites are closed acting as roservoirs, to hold
the ordinary drainage from the surrounding hills.

In ordinary cases the sloughs have not enough oapuciiy to hold the
drainage during the time when the gates are closed, and pumping has
to be res Ttcd to, for about a month in the year.

One of the most difiicult operations connected with these schemes is
the proper designing and construction of tliese boxes. It is a very
difficult matter to keep them tight, and the material in and surround-
ing these sloughs is such that when once the slightest leakage occurs,
under pressure, it is a very short time until the whole box finds its way
into the river or up the slough.

Again the many and varied kind of sloughs and creeks, the dif-
ferent classes of material through which they paB.s, varying from
gravel and sand, to silt and clay, the fact that some discharge into the
river where there is a regular rise and fall due to the tide, while others
discharge at points where the tide docs not reach — (the gates of the
former having of necessity to close and open during each tide, while in
the latter they need only close during the freshet) — all tend to require
very careful examination and much experience before deciding upon
the proper design for the gates.

In fact, almost every locality requires u gate of a design unique in
itself, with some special features differing iprobably very materially
from that required in a locality not half a mile distant. The boxes
required for the sloughs located on the river above the effect of the

(ides tire subjected to a very sovcro test and strain during high water.
Tlie^ arc often subjected to a pressure of water due to a head of from
1 8 to 20 feet and lasting from a month lo six weeks. On tlie otl'.cr
hand, those located on that part of the river atteeted,hy tidal waters arc
relieved twice every day during ubb tide.

The writer "ives a description of two of these boxes built by l.ini,
one in Marcli, April and May, and the other in August and Septem-
ber, 1896", all being under the same contract. They aro built in two
slougiis discharging into the Fraser, through what is known as the
Matgqui Prairie. They were designed in 1893 by Mr. Fred. J. L.
Tytlcr, C.E., at present supervising engineer for reclaiming lands for
the Provincial Government of British Columbia, and were built with
several changes under contract by the writer. The plans attiiched with
this paper are those upon which they were actuully built. It may
also he mentioned that in each of these 8lou<>hs prior to the construc-
tion of the ones described there had been built three diflFcrent and din-
tiiict boxes each of which hud succumbed to the effects of the freshets,
and had been torn apurt or scoured out, and carried by the flood for
long distances over the prairies.

One of the present boxes, the only one built at the time, was sub-
jected to a V(ry heavy freshet 'n July last, the water in the river
reaching to a point only 2 feet 11 inches below that reached during the
disastrous flood of 1894J; but althouuii the work was barely completed,
when the flood came, and had in consc'(|uenco barely reached its true
bearing, still there was no sign of lenkagc, or scour, or damage in any
one particular. The lumber used in the boxes was all of rough sound
cedar, with the exception of the clappers or doors, which were of dressed
Douglas fir. The boxes are identical in design, each being 80 feet long
by 26 feet wide by 5 feet 8 inches outside measurement, having four
openings each 4 feet by 5 feet. They have also each an entrance npron
30 feet X 40 feet, and a discharge apron 60 feet x 40 feet ; each con-
tains about 90,000 feet B.M. The plans attached give a general
idea of the timber-work. All spikes were specified to be galvanized.

The most important part of the work is the method of setting the
box, and the proper placing of the brush and eliiy and pickets, and this
will be now described.

At this point of the Fraser Elver, there is an ordinary rise and fall
of tide, due to the backing up of the river, of about 4^ feet, while
during the freshet no difference of rise and fall is perceptible. Both
boxes being identical in design it is only necessary to describe the
manner of placing one — the most difficult— and located in what is
known as No. 3 slough,

This slough as shown on the pbn is about 80 feet wide at the top,
and from 25 to 30 feet deep, with water at the time of construction
about 10 to 10 feet deep. It drains a largo portion of the prairie,
besides receiving a large creek from the surrounding hills, and as the
weather was very wet at the time, it was necessary for it or the off-take
ditch to carry away a large amount of water. The banks of tiio
slough sloped at about | to 1 and were interwoven with roots, and gave
signs of sliding from adjicent springs and seepaiju of water.

The method devised and afterwards adopted for placing the box
was to build a tempoiary dam u short distance above the site of the
box, another a short distance below the site, excavate an off-take ditch,
and having pumped out the portion of the slough between the dams, to
commence operations. The off-take ditch was excavated through fairly
good clay, being about 12 feet wide ut the bo'.tom, with side slopes of
aboat 1 to 1, and varying in depth from 4 to 14 feet.

In construetini; the upper dam a crib of lo^s was first built across,
notched down and securely drift-bnlicd together, the logs on the upper
side having a batter of about 6 iiiuhcs to the foot. Along the upper
side were driven sheet piles, consisting of 3 and 4 inches plank which
penetrated from 4 to 8 feet into the bottom, but on account of the
presence of many sunken logs and stumps, it was impos:iible to get all
tht! plank down to a proper bearing, but they were intended merely to

«L*^~

siw.*.

of sand bein^ Gnc, This when left in its natural bed, and not dis-
turbed, is impervious to water, but once it is moved and displaced,
and exposed to the action of water under pressure, it becomes a
veritable quick-saiid. Beneath this was a bed of fairly course red
sand.

After having imidc this examination, the cause of the former boxes
havin<i been scoured out was apparent to the writer. They had been
consirueted in the form of coffer-dams built by driving rows of sheet
piles braced to ordinary piles, and filling the intervening space with
earth or clay. These piles had pcnotrateJ this bluish silt, and were
driven into the red satid. When the water acquired the necessary
head on the outside, after the closing of the gates, it followed down the
piles through the silt, into the sand and up again on the other side.
The intervening earth was soon washed out, and with it the bottom of
the piles, until a channel wns Jbrined underneath, and very little time
elapsed before the whole structure was scoured out.

After having been enlightened us to the nature if the bottom, it
was decided to lay the foundation upon tliis bed of bluish silt, without
disturbing it more than necessary. This was done after all the
decayed material — logs, ooze, etc. — had been removed from the bottom,

• '^i^ii^ijnrrfs. .TTT--

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— iaE(e[LAKlATril®l?3 —
FLOOD BO X AND GATE

OETA4t. CtAPP£R

m»»^^h<^* e^ sleuth

LGNG+TUD+NAL SECTION

besidoa receivin»- a larf^o creek from the ,s

iirrouD-Jiut; hills, and as thn

LEY

GATE

TRANSACTIONS CAN. SOC. C.E.,

VOL.XI. PLATE I. .

\ruah

€«0&& SECTION

//■ni/ /«/V K,^ Kmp »ut»>'J» af A/tnn WmHs.

fON

ills, and iis the

of sand beinj? fine. This when left in its natural bed, and not dis-

.k.

liilcH lire Hubjoctitd to a very severe tcitt ami utraiii (luriii<^ hij;li water.
Tlioy lire often subjecUjd to ii pri'smire of wiitor duo to a head of fVom
IH to 20 tV'ct and laslini; from a niontli to nix weikn. On tlie otli.T
hand, tliosc loeuicd on tliat pait nt' tlic riviT rtlti'ctrd.by tidal watcif arc
relieved twice every d.iy during Mt tide,

The wriU'r f;ives a dcscriptiKn of two oC ihose boxes built by l.iiii,
ODO in March, April and JMay, and the otliei' in Au^U8t and Scptcoi-
ber, IHOft, all being under the same contract. They aro built in two
sloughs dieciiarging into the Frascr, through what is known as the
Matsqui Prairie. They were doigni'd in 1H93 by Mr. Fred. J. L.
Tytler, C.K., at jircsont supervieiiij; engineer for rrelainiing lands for
the Provincial Qovcrnnicnt of Britisli Columbia, and were built with
severid changes under contract by the writer. The plans attiiclud with
this paper are those upon which they were actuully built. It may
also be mentioned that in each of these slou;:hs prior to the construc-
tion of the ones described there had been built three different and diii-
tinct boxes each of which had succumbed to the effects of the freshets,
and hud been torn apart or scoured out, and carried by the flood for
long distances over the prairies.

One of the present boxes, the only one built at the time, was sub-
jected to a VI ry heavy frosliet in July lat-t, the water in the river
reaching to a point only 2 feet 11 inches bilow that reached during the
dlsi)8trou8 flood of 1894j; but althou!:li tlic work was barely completed,
whin the flood came, and had in eonsc'<|ueucc barely reached its true
bearing, still there was no sign of leakage, or scour, or damage in any
one particular. The lumber used in the boxes was all of rough sound
cedar, with the exception of the clappers or doors, which were of dre.sscd
Douglas fir. The boxes are identical in design, each being 80 feet long
by 2U feet wide by 5 feet 8 inches outside measurement, having lour
openings each 4 feet by 5 feet. They have also each an entrance apron
30 feet X 40 feet, and a discharge apron CO feet x 40 feet ; each con-
tains about 90,000 feet li.M. The plans attached give a general
idea of the timber- work. All spikes were specified to be galvanized.

The most important part of the work is the method of setting the
box, and the proper placing of the brush and clny and pickets, and this
will be now described.

At this point of the Fraser Bivcr, there is an ordinary rise and fall
of tide, due to the backing up of the river, of about 4^ feet, while
during the freshet no difference of rise and fall is perceptible. Both
boxes being identical in design it is only necessary to describe the
manner of placing one — the most diflScult— and located in what is
known as No. 3 slough,

This slcugh as shown on the pl»n is about 80 feet wide at the top,
and from 25 to 30 feet deep, with water at tiie time of construction
about 10 to 1() feet deep. It drains a large portion of the prairie,
besides receiving a large creek from the surrounding hills, and as the
weather was very wet at the time, it was necessary for it or the off-take
ditch to carry away a large amount of water. The banks of tho
slough sloped at about ^ to 1 and were interwoven with rootfi, and gave
signs of sliding from adjicent springs and seepage of water.

The method devised and afterwards adopted for placing the box
was to build a tempoiary dam u short distance above the site of the
box, another a short distance below the site, excavate an off-take ditch,
and having pumped out the portion of the slough between the dams, to
commence tperations. The off-take ditch was excavated through fairly
good clay, being about 12 feet wide at the bi>'.tom, with side slopes of
about 1 to 1, and varying in depth from 4 to 14 feet.

In constructing the upper dam a crib of lof;s was first built across,
notched down and .securely drift-bolted together, the logs on the upper
side having a batter of about G inches to the foot. Along the upper
side were driven sheet piles, consisting of 3 and 4 inches plank which
penetrated from 4 to 8 feet into the bottom, but on account of the
presence of many sunken logs and btumps, it was impossible to get all
the plank down to a proper bearing, but they were intended merely to

hold the \)T\xf>\\ QDfl rarth, iiflerwards cnnvcyrd in, from being Kwcpt
down by tbo currtMit so hodii as it was deposited.

At fiiHt it waH coni-idfii-cd piiiciicablu to coinmciico tliis sheet pilini;
at one sidi', and eontinuc aloni:, finishing at the otlior, but it was found
tlint the bunlss wcru of i-uch a ireaeherouH niiturc, that the increased
current due to the niirrowinjj; of the channel would wour away the
hanks nioro quickly tlmn the sh'ct piles could be driven, an<l thus
dos'roy the ircation of the box. It was then decided to commcnco at
bf'tli ends, njuko them tiiorou^idy sceuio, and work toward the center.
Tliis w;is done, the sheet pilinj;; from eaeli ."ido boinj; closely followed by
1 ibourcrs duuiping cJirlh to form nn embankment on the upper side of
the crib, keepini: plenty of brush on the outside, to prevent the earth
being scoured away by thn current. After liavin;; proceeded thus to-
ward the center, and wh'n the current became too strong due to the
narrow opening; to liold tlie earth from being washed away, the pip in
the sheet piliiij; was closed, and the liaekint,' deposited as soon as pos-
sible. I5ut the material in the bottom of the slnufih was of such a
treacherous nature, that no .sooner had the waler on the upper side
benun to rise on the piiinj^thm it broke tlirou^h underneath, the water
followin"^ the piles down, where it encountered a coarse red s»nd, which
was soon scoured out, and in a very short time an open channel was
made undcincnth the pilin<r.

Sacks were immediately obtained and filled with earth (about 1,200
of them), and these diinipcil into the ciiannel or hole with loose hay and
earth, finally lieM the enrrent until alarf^cearth einbankinent was built
across. No more trouble was al'terwards encountered, althouf;;h it was
subjected at one time to a pi'essure due to a 27 foot head. The lower
dam was built in much the same way, but with less difficulty, there
bein<4 only a 4 leet tide to contend against.

The speciliciitions re(|uiied ail no/.e, logs, stiek.^ or perishable matter
to be removed IVoiu the bottom of ihe slou-^h, between the two dams,
to a maximum depth of li f. et below the bottom of the box, in order
to secure a proper foundation on wliich to lay the brush and cliy.
Should the material below that be soil and mushy, then wild hay was
to be tramped in below ihat again, until a firm bed was obtained.
Hat it was to be left to the judgment of the engineer as to how deep up
to the six feet the excavation was to be made.

After having pumped out the location— a centrifugal pump with a
4 inch discharjie having been used with a maximum lift of cbout 15

feet Ihe bottom of the slough was carefully examined and the material

tested. Tlie first 2 leet or thereabouts consisted of ooze, aliine, brush,
logs, slumps and every imaginable kind of wortiiless matter. Beneath
this for from 4 to <) feet was a bed of silt, of a bluish color, containing
minute particles of mica, and very gritty to the touch, but the particles
of sand being fine. This when left in its natural bed, and not dis-
turbed, is impervious to water, but once it is moved and displaced,
and exposed to the action of water under pivssure, it becomes a
veritable quick-sand. Beneatli this was a bed of fairly cour.se red
sand.

After having made this examination, the cause of the former boxes
having been scoured out was apparent to the writer. They had been
constructed in the form of coffer-dams built by driving rows of sheet
piles braced to ordinary piles, and filling the intervening space with
earth or clay. These piles had penetrated this bluish silt, and were
driven into the red .sand. When the water acquired the necessary
head on the outside, after the closing of the gates, it followed down the
piles through the silt, into the sand and up again on the other side.
Tlic intervening earth was soon washed out, and with it the bottom of
the piles, until a channel was Ibrmed underneath, and very little time
elapsed before the whole structure was scoured out.

After having been enlightened as to the nature if the bottom, it
was decided to lay the foundation upon this bed of bluish silt, without
disturbing it more than necessary. This was done after all tho
decayed material — logs, ooze, etc. — had been removed from the bottom,

mid iill roolH, itliJeN nnd Iooho iiiiitoriul cleaned oflf t)i*t xidoa of the
blinks, anil proper hIoih-h of nlmut IJ to I excavated from tlioiii, Tho
fouiidiiiiiin under the box proper was built up of elay nnd bruHb, that
under >'aoli apron of lip-nip.

Clay, — The npieilientionH fur the oliiy rend bh follows ; — " To b«
of flritt eliiN.x qunlily, und wlicii kneudud >titi into n pyniniid of nn inch
or H) in liei;:lit, and iiunierKed in water, will renmin intact for 24 hourt*
witliout oruiublin'.'."

Bruhii. — " To bo of ureoii bushy fir or ccdur trees, of younn
growth, not mure than I'l feet in length, wbrn tho nteni is cut 0I080
to tliu head, whiuh it shiili be, or linibH Nimilar in character."

The -eparate limbs were tiftcrwards prncticiilly oxcluded, and brush
allowed much longer than specified, which served tho purpoao better.
The Hist intention of the writer was to obtain tho olay from a bed
about a niilu up the sh)Ugh, above the site of the box; but aflor the
temporary dams iiad been built, a great quantity of niiii fell, and as
the off-take never wna intended to carry off all the drainage, the water
backed up, so that tho elay could not bo reached. Another bed of
blue clay of excellent (juality was liien located on iho river bank, about
two miles below the mouth of tiio slough, and was conveyed by steamer
and scows at a heavy expense.

FoiNDATiON. — This was laid as follows : — A bed of this olay was
deposited on the bot'.om nf the slough about 2 feet in thickness, and
HO feet in length, that is nndor the site for the Ijox pioprr. This won
laid in layers a few inches in thickness, caiel'ully spread and levelled,
and well tramped and pounded down. (^11 top of this was laid a row
of brusli with butts to the end. These small trees were laid close
together longitudinally, from one side of the slough to the other, and
at ono end of thu foundation. The branches standing up were
" nicked " in order to let them lie close. After tho first row was laid,
another wos placed on top partially covering the first layer, similar to
shingling a roof, butts all lying out in the same way as number one
row. Then another row was laid in a similar manner, until the layer
of clay below (HO feet in length) was covered for about two-thirds the
distnnce from one end, or between .'iO or 00 feet. After this had been
completed a layer of clay was laid on top from 1^ to 2 feet in thickness,
covering the whole foundation. This was thoroughly compacted, and
tramped down with horses and then levelled tip. Upon the top of this
clay was laid another layer of brush .similar to the lower layer, but
this time commencing at the opposite end of the foundation butts out,
and exteniling for about two-thirds of the way towards the first end,
and thus overlajipiug a portion of the fir.st I'lyer of brush, but care
being taken that there was a good layer of clay between, so that tho
brush in no in<>tanee would be coutinuou.s through the entire length of
the foundation. Upon the top of this was laid another layer of clay
similar to tho previous layer and so on, until tho proper height was
obtained to lay the box.

The accompanying plate Is intended to show a longitudinal section
through the foundation.

When the foundation reached the required height, it was carefully
levelled off and made ready for the box. The lower planks of the box
floor (f) X 12 X 2ti feet) were then laid clo.se together, each one being
levelled up and pounded down with a heavy pounder, until it lay on an
even bed throughout, in contact with the clay. Upon the top of this
floor was built the box as shown on the plan.

From the box to each bank of the slough was laid clay and brush in
a similar manner to that in the foundation, care being taken that in no
ease should the biush extend in a continuous layer right through the
embankment, or that it should touch the sides of the box. The clay
was laid in thin layers and thoroughly tamped and pounded down,
especially close to the box, and also carefully knitted into the banks on
each side by key walls. A brush and clay embankment laid in this
manner was carried up on each side and on the top of the box, until the
top of the banks of the .slough were reached, with the exception that,

rtftor tlin top (if th(i box Icvol won ronohod, tlio slopoH on onch cnJ wore
rairind up by driving' Mplit cudiir piokuti* about ',\ iiicbcx in dinnictcr
iinil t> incliL'H apiirt, -l ffct into tln! (^nibnnkuicnt, — I'aeh row boinij; 1 foot
bi).'li('r than tin? iirwcdinj^ oni', and 1 fiiot ni^aror tho center i»f thn
liox, tbiiH luakin}; ii xjiipc of 1 to I at tluM-ndg. Hvbind, or inside each
row of piukuirt, waH laid " licndin;; bruHh' or brusli laid tranivoracly
with the box to keep liui clay in plitoe. From tho top of the bank of
tho hIoukIi, n dyke of nrdimiry earth work was built lothe height of tho
river dyke, about two feet above maxiDiuiii hi;{h water.

Tho aprunH were built ^^ .shown on the plan, the walls flaring out
from the endn of the box to the end of 'he apron, and rip rap being hand
laid oulHiile of the walls upon the flcuir, tn load it down, From the rip.
rnp wnllN tn ilio luinkfl, the fhpcN were built of rouph brush and ordin-
ary tiurth, laid in a similar manner to the olny and brush.

GATES OH CLAPPERS.

The gates or clappers used on thu box, a detail of one of which is
shown on the plan, arc of the " top hung " pattern. A difference of
opinion seems to exist among the engineers of this district, as to advan-
tiiges derived from that style over the " nido hung " gate. The trouble
expoi'ienced with the gates on this box was as follows : when the
freshet first begins to cume, tho river only rises a few inches in 24
hours, and, according to the state of the weather, may in its steady
rise never exceed (! to 12 inches in one Jay, Consequently, the gates
not being bung perpendicularly, but when closed have a batter of about
1 inch in 12, — the water keeps running in underneath the clapper, fill-
ing tho slough in,fide, as (niickly or nearly xo, as the river rises outside,
and the clapper to all intents and purposes floats on the Htroam, there
being practically no prcs,surc against it, at least not enough to close it.
Weights were attaehcd to the bottom of the clapper which assisted
materially in closing them. In the case where the water rises rapidly
fiutsidc, us in tidal waters, no tioiible is mccuntertd, for once it begins
10 rise, a lead viiy mjiidiy foinis, and the gates willclo.sc with a sound
as of the discharge of a cannon. Another disadvantage of the "top
hung" gate is this ; when the sloiigli is discharging, the water insido
as a rule is very slightly higher than the falling water outside. Also
there are always more or le,«8 branches of fallen trees, sticks, pieces of
logs, etc., being carried out through the boxes. These must necessarily
pass underneath the slightly opened clappers, and in many cascH arc
caught between the floor of the box and the bottom of the gate. Then
when the tide changes, and the water turns to flow back into the slough,
the debris prevents the particular gate from closing. Well designed
grillnges both above and below the gates ward off much of the debris,
but notwithstanding this it is impossible to keep some branches, fence
rails, etc,, from passing through.

In the " side-hung " gates, less trouble is encountered from this.
Here tho gates are hung in pairs, closing at tho center of the openings,
the debris can then float upon the top of the water, and not being
dragged along the bottom of the box, has only the two edges of the gates
to encounter, and the gales being evenly balanced, will open enough to
allow the debris to pass through. This difficulty of course is only
encountered when the head on either side is small, and the gates in
consequence are very slightly opened. In " side hung " gates there is
a slight disadvantage in that it is very difHcult to prevent the gates
from sagging through length of time, which prevents them from closing
tightly. They must bo well designed with very heavy and strong
hinges.

In many of these boxes on the Frascr, the gates are hung on tho
outside of the box, and have an advantage that they are more easily
reached should anything prevent their closing during high water.
These gates cost practically $10,000 each.