CHAMBLY.CANAL FLOW DIVERSION TEST

A p r i l 1979

Ad Hoc Committee I n t e r n a t i o n a l Champlain-Richelieu Board

November 2, 1979

Environment Environnement I* Canada Canada

Water Planning & Management Branch Ottawa, Ontar io K I A OE7

November 8, 1979

M r . M.W. Thompson Chief ~ n ~ i n e e k In te rna t iona l J o i n t Commission 100 Metcal fe S t ree t Ottawa, Ontar io K I P 5M1

Dear M r . Thompson:

I am pleased t o forward herewith 20 copies o f a r epo r t dated November 2, prepared by an ad hoc committee, t o monitor the f l ow through the Chambly Canal. You w i 11 r e c a l l t h i s committee was formed by the Commission a f t e r the f l ow d ive rs ion t e s t had commenced. The experience gained i n the t e s t was l i m i t e d because o f the shor t durat ion o f the t es t , p a r t i c u l a r l y a t maximum flow. The Comnission should therefore note the caut ion expressed on page 15 against drawing any conclusions from the t es t s as t o the

,merits o f the Canal d ive rs ion concept.

A s i m i l a r l e t t e r i s being sent by the U.S. Chairman o f the ICRB t o M r . Fonda.

- .

-Yours s incere ly ,

H.B. Rosenberg Chai rman ICRB, Canadian Sect ion

C.C. M r . T.P. Curran

1. INTRODUCTION

As p a r t o f an improvenient program f o r t he Chaliibly canal, the Canals

branch o f Transpor t Canada, now p a r t o f Parks Canada, c a r r i e d o u t c e r t a i n

cons t ruc t i on work on the canal a t S t . Jean, Quebec between 1970 and 1974.

The work i n p a r t i nvo l ved widening a sec t i on o f t h e canal by moving t h e

o u t e r w a l l approx imate ly 100 fee t f a r t h e r ou t i n t he r i v e r . The l o c a t i o n o f

t he widening was a t the St. Jean shoal which ac t s as t h e h y d r a u l i c con t ro l .

a f f e c t i n g Lake Champlain l e v e l s and outf lows. The e f f e c t was t o c o n s t r i c t

t he r i v e r and r e s u l t e d i n a one-time s h i f t o f t he stage d ischarge r a t i n g

curve o f Lake Champlain. This change i n t h e r a t i n g curve i s g rea te r a t

h igh f lows. The recen t I n t e r n a t i o n a l Champlain-Richel i e u Board s tud ies

evaluated t h i s s h i f t i n the curve due t o t h e canal widening a t about 0.30 f e e t

under f l ow cond i t i ons of 40,000 cfs. # .

~ f t e r becoming aware o f t he i nadve r ten t e f f e c t s o f t he canal widening,

Parks Canada decided . t o conduct a t e s t program us ing l ock No. 9 and a s e c t i o n

o f the canal t o increase the R iche l i eu R iver d ischargb and thereby lower

upstream water l e v e l s . The t e s t program was scheduled f o r t he s p r i n g o f 1979

be fo re the opening of the nav iga t i on season. The o b j e c t i v e was t o t e s t t he I I

s t r u c t u r a l and h y d r a u l i c competency o f t h e canal as a bypass channel and t h e 1 /

f e a s i b i l i t y o f p a r t i a l l y compensating f o r t h e canal widening i n t h i s manner. f I I

Parks Canada engaged an engineer ing consu l tan t , Donald Car te r o f Quebec ~i tyi I

who designed a d i v e r s i o n system, based on h y d r a u l i c ana l ys i s , which would 1,

o f f e r a degree of s a f e t y t o s t r u c t u r a l components. To eva lua te t h i s design

and assess the h y d r a u l i c e f f e c t s o f t he d i ve rs ion , a mon i to r i ng program was

The I n t e r n a t i o n a l J o i n t Con~nliszion ( I JC) , f o l l ow ing n o t i f i c a t i o n by the

Government o f Canada o f the t e s t , requested the I n t e r n a t i o n a l Champlain-

R iche l i eu Board t o form an ad hoc committee t o mon i to r the h y d r a u l i c e f f e c t s

o f the program. This request was confirmed i n l e t t e r s t o the Board Chairmen,

dated A p r i l 19, 1979 (copy at tached). The Committee, comprising th ree U.S.

and th ree Canadian members, was formed and met w i t h Parks Canada on Apr i 1 17,

1979, a t which t ime a mon i to r ing program was formulated. This was o u t l i n e d

i n a l e t t e r t o bo th the U.S. and Canadian sect ions o f t h e Commission, dated

Apr i 1 25, 1979.

This r e p o r t presents a d e s c r i p t i o n of the t e s t program, schedul ing,

procedures, data c o l l e c t e d and an assessment o f the e f f e c t s as determined by

the ad hoc committee. The f i e l d t e s t s were conducted du r ing the p e r i o d

A p r i l 10 t o 24, 1979.

2. TEST PROGRAM

2.1 Hydraul i c Concepts

The S t . Jean shoal ac ts l i k e a t r u e hyd rau l i c c o n t r o l f o r a l l ranges

o f l e v e l s and outf lows o f Lake Champlain. Water l e v e l s upstream o f S t . Jean

are there fore in f luenced almost e n t i r e l y by the shoal. Any physical change

(e . g . , erosion, dredging, cons t ruc t ion , en1 argement) a t t he c o n t r o l sec t i on

would a f fec t the water l e v e l s upstream. Any changes (e.g., sedimentat ion,

c o n s t r i c t i o n ) downstream of the c o n t r o l sec t i on would n o t a f fec t upstream

water l e v e l s unless the changes were of such magnitude t h a t the c o n t r o l . .

secti.on was p a r t i a l l y o r completely drowned ou t o r a new c o n t r o l s e c t i o n

formed. For example, s u f f i c i e n t dredging a t t h e S t . Jean shoal cou ld

t r a n s f e r the c o n t r o l of Lake Champ1 a i n l e v e l s downstream t o ' f r y e r s I s l a n d dam.

By us ing the sec t i on of the Chambly canal t h a t bypasses the shoal f o r c a r r y i n g

additional Richel ieu River flows, the control i s effect ively changed, i . e . ,

thf: capacity i \ incrc?accd and thus (1 1 f ( ~ . t . ~ , ul)s troaa~ w n t c r 1 cvels. The illtl)dct

on upstream water levels i s dependent. on how a~uch additional flow is pascing

through the canal.

Figure 1 shows the portion of the Chambly canal bypassing the shoal.

I t extends from the upper entrance down to the lower extremity of the

recently widened section, a distance of about 5,000 fee t . Within th i s

section i s lock No. 9 , the l a s t lock in the canal system. The lock chamber

i s 24 fee t wide and 110 feet long between gates.

The diversion concept was to admit water into the canal by. way of the

sector guard gate near the entrance, jus t above the Gouin bridge, and t o

return the water to the r iver , through a temporary breech in the canal wall ,

downstream of the shoal. The upstream head ranges between 5 and 6 f ee t ,

depending on the r iver stage. Lock No. 9, because of i t s dimensions compared

to the res t of' the canal, would normally operate as the hydraulic control

unless steps were taken to t ransfer i t elsewhere. Therefore conditions

downstream of the lock in th is s i tuat ion would not a f fec t discharge . .

capabili ty. With hydraulic control a t the 'lock, velocities in the lock would

be a concern and could endanger the s t ructure. An analysis was ca'rried out I by the consultant to' evaluate conditions of diversion flow, estimate flow

ra tes , and design an out le t structure. The following two al ternat ive

conditions were considered i n the computations:

( 1 ) Hydraulic control a t lock No. 9. Canal discharge under . th i s condition

will depend on the elevation of the water surface a t t h e canal entrance,

u p s t r e a ~ ~ ~ of the guard gate, 1 ess head losses in the canal upstream of

the lock.

I . . ./

( 2 ) Hydrau l ic c o n t r o l a t the temporary o u t l e t of t he canal. Under t h i s

cond i t i on , backwater from the o u t l e t would drown o u t t h e c o n t r o l a t

t he lock . Canal discharge i n t h i s case would depend on the water

sur face e l e v a t i o n a t the canal entrance, upstream o f the guard gate,

l ess head losses throughout the t o t a l d i v e r s i o n l eng th o f canal . '

Fur ther c o n t r o l of canal discharge cou ld be exerc ised by ope ra t i on o f

the guard gate. This would l i m i t t h e amount o f water e n t e r i n g t h e canal .

I n t h i s case, hyd rau l i c cond i t ions i n the d i v e r s i o n would be determined by

the water l e v e l immediately downstream of the guard gate, i ns tead o f a t t h e

canal entrance upstream o f i t . I n o the r words, t h e guard gate would a c t as

the f low c o n t r o l whi le'downstream hyd rau l i c cond i t i ons (such as the water

sur face p r o f i l e ) would be c o n t r o l l e d by e i t h e r l ock No. 9 o r t he temporary

out1 e t .

The hyd rau l i c ana lys is i n d i c a t e d t h a t w i t h c o n t r o l assured a t t he l ock

by an e x i t o f s u f f i c i e n t s ize , v e l o c i t i e s cou ld reach 15 f e e t per second i n

the lock. The consu l tan t considered t h a t these would be unacceptable f o r

l ock sa fe ty . By cons ider ing an o u t l e t of a s i z e t h a t would ensure e x i t

c o n t r o l f o r a1 1 cond i t i ons o f flow, l ock v e l o c i t i e s we~re reduced t o the 8 t o

10 f e e t ' p e r second range which would be acceptable. It was on t h i s bas is

t h a t t he hydraul i c condi t i o n was es tab l ished f o r the d i ve rs ion . The requ i red

o u t l e t s i z e f o r t h i s c o n d i t i o n was ca l cu la ted t o be a w id th of 20 fee t .

2 .2 Mon i to r ing Program

I n order t o assess t h e hyd rau l i c ef fects of the d ivers ion , a mon i to r i ng

program was planned. It was designed t o co l l e c t water l e v e l and discharge

data f.or the purpose o f determin ing upstream impacts of the d i v e r s i o n f lows.

The data would a l s o be useful f o r model c a l i b r a t i o n i n any f u t u r e h y d r a u l i c

studies o f the canal system. It could a l so be useful f o r comparing design

versus ac tua l cond i t ions . F igure 1 shows the l o c a t i o n s of mon i to r ing s t a t i o n s .

These were agreed upon by the ad hoc committee a t i t s A p r i l 17 meeting w i t h

Parks Canada, al though d i v e r s i o n had commenced before t h a t date and w i t h l ess

i n t e n s i v e moni tor ing. The agreed program was as fo l lows:

( 1 ) Water l e v e l e levat ions t o be determined a t t he se lec ted loca t ions

.- f o r every change i n guard gate s e t t i n g , appreciable upstream r i v e r

l e v e l changes and a t t he t ime o f discharge measurements.

( 2 ) Accurate measurements of flow through the canal t o be made f o r every

gate opening, as w e l l as fo r appreciable changes i n r i v e r l e v e l which

a f f e c t discharge i n the canal.

2.3 Scheduling and Preparat ions

The t e s t program was scheduled to .beg in i n A p r i l du r ing the h igh water

period, which usua l l y occurs i n the e a r l y p a r t of t h e month. The p lan was t o I

d i v e r t f low u n t i 1 approximately May 1, a t which t ime the f a c i 1 i t i e s would have

t o be readied f o r t he forthcoming nav igat ion season.

Preparat ions f o r t he t e s t were c a r r i e d out i n March. They inc luded

cons t ruc t i on of t he o u t l e t and c,losure of the .canal, immediately. below it., . , .

This work invo lved breeching the canal w a l l dyke, d r i v i n g a s t e e l sheet p i l e I p r o t e c t i v e wa l l and w e i r sec t i on and b a c k f i l l i n g the adjacent canal channel.

. - 3.1 Descr ip t ion

On A p r i l 10. d i ve rs ion through the canal commenced. The guard gate b -. was opened i n stages b e g i n n i n j a t 2.5 f e e t and progressing i n increments t o

7.0 feet . Mon i to r ing was l i m i t e d t o some gauge readings and a p re l im ina ry --

eva luat ion of v e l o c i t i e s i n t h e lock .

. . ./

On A p r i l 11, the quard gate wds opened t o 8.4 feet which produced a

vr:locit.y i n t.he lock o f 6.0 f c c t pctr c.chc:or~d. I-ro111 t h i r d a t e l j n t i l 4.00 p.al.,

A p r i l 20, the re was a continuous d i v e r s i o n f low. Between 8.00 a.m. and 4.00

p.m. d a i l y , an 8.4-foot gate s e t t i n g was maintained; du r ing the remaining

hours of,each day, t he opening was reduced t o 7.0 f e e t .

On A p r i l 18, an i nspec t i on revealed up t o 4.0 feet o f e ros ion i n t h e

bed o f the canal, i n t he cent re of the channel immediately downstream of t h e

guard gate, as w e l l as breakage of an underwater Hydro Quebec cable. As a

r e s u l t , the d i v e r s i o n was suspended on A p r i l 20. However, i n o rde r t o have a

more complete eva lua t i on of t he system, i t was decided t o conduct a oneLday

t e s t running through a se r ies of guard gate openings, up t o f u l l opening, '

w i t h r e s u l t s monitored as recommended by t h e ad hoc committee. This was

undertaken on A p r i l 24 between 8.00 a.m. and 10.00 p.m., a t which t ime t h e

sys tem was c losed and d i vers ion t e s t s termi nated.

Flows i n the canal were determined by v e l o c i t y measurements taken . . . ._: : J . . * .

a t lock No. 9,' a t t h e sec t i on i n d i c a t e d on Figure 1 , us ing a c u r r e n t mete*

and standard s tream-gaugi ng procedures.

3 .2 Results

Data c o l l e c t e d from the t e s t s a re prov ided on Table 1. The i n fo rma t ion

f o r the most p a r t i s se l f -explanatory. The impact on water l e v e l s and

discharge f o r var ious cond i t ions i s ind ica ted . For t h e A p r i l 24 t e s t s , water

l e v e l s and discharges shown on the t a b l e r e f l e c t s t a b i l i z e d h y d r a u l i c

cond i t ions i n t he canal f o l l o w i n g gate opening movements. As i nd i ca ted , the

~i~axi i l lu~r l water l e v e l lower ing measured a t t h e S t . Jean Marina gauge was

0.1t3 fee t , fro111 e l e v a t i o n 97.50 t o 97.32.

A study o f t he recorded l e v e l s on Lake Champlain f o r t he t e s t p e r i o d

d i d no t reveal any de tec tab le ef fects of t he d i v e r s i o n f lows.

F igure 2 shows t y p i c a l water surface p r o f i l e s through t h e canal

d i v e r s i o n sec t i on a t var ious gate se t t i ngs . Figures 3 and 4 a r e photographs

o f the guard gate and t h e o u t l e t s t r u c t u r e , respec t i ve l y .

The on l y adverse - s t r u c t u r a l e f fects due t o these d i v e r s i o n t e s t s

through t h e canal was eros ion below the guard gate, as p rev ious l y mentioned.

This was due t o the t u r b u l e n t f l ow cond i t ions immediately downstream when t h e

gate was p a r t i a l l y open; a t f u l l gate opening t h i s d i d n o t occur. L i t t l e o r

no eros ion was no t i ced on canal banks.

4. ANALYSIS OF RESULTS

Data .ga.thered du r ing the . Apr i 1. 24-25 phase. of the, program were analyzed . . . .

w i t h a view t o determin ing how much a d d i t i o n a l w a t e r 'was discharged.-

A. p e r i o d o f 134 hours elapsed from the f i r s t opening o f t he guard gate,

a t the s t a r t o f the t e s t a t a 2 - f t . s e t t i n g , u n t i l i t was c losed a t t h e end o f

the t e s t a t the 5 0 - f t . maximum s e t t i n g . A t o t a l volume o f 19,630 cfs-hours

6 3 (2.001 x 10 M ) of water passed through the canal d i v e r s i o n sec t ion . A t each

incrementa l l y wider gate s e t t i n g , the canal f l ow increased, t o a measured

3 maximum o f 2,285 c f s (64.7 M /set.), and the water l e v e l a t t he S t . Jean

Marina gauge was progress ive ly drawn down, u l t i m a t e l y by 2.1 inches a t the

~ilaximum f low. Lowering of t h i s upstream r i v e r water l e v e l accord ing ly --

reduced the flow over t he na tu ra l c o n t r o l a t t he shoal , l i k e w i s e progress ive ly .

3 A t t he maxiniuin d i v e r s i o n cond i t ion , the f l ow reduct ion was 1,308 c f s (37.0 M /

,. sec.), t h i s being 4.6% of t he r i v e r f low a t t h a t t ime. The reduc t i on i n t he

volume of water passed down the r i v e r du r ing these 13: hours was 10,460 c f s - * 6 3 hours (1.066 x 10 M ) . The ne t a d d i t i o n a l volume discharged was thus 9,170

6 3 cfs-hours (0.935' x 10 M ) .

With c losu re o f t he guard gate a t the conclus ion o f - t h e t e s t , t h e

r i v e r began t o r e t u r n t o i t s previous cond i t i on . I t s recovery, i n v o l v i n g

replenishment o f t he e x t r a water withdrawn from the upper reaches o f t h e

r i v e r , e l i m i n a t i o n o f the 2.1" of draw-down a t t he Marina gauge and thus

r e s t o r a t i o n o f t he p r e - t e s t f low over t he shoal, occurred g radua l l y over t h e

ensuing 13 hours. During t h i s pe r iod the reduc t i on i n t he volume of water

6 3 passed down the r i v e r amounted t o a f u r t h e r 4,950 cfs-hours (0.505 x 10 M ) .

Thus the f i n a l n e t a d d i t i o n a l volume of water passing S t . Jean was

6 3 4,220 cfs-hours (0.430 x 10 M ). Table 2 summarises the S t . Jean l e v e l s and

f lows data. . , The reduct ion i n f low over t he shoal, due t o t h e lower ing o f t h e

upstreamwater l e v e l when water was being d i v e r t e d through t h e canal, was

computed from the stage-discharge curve. As a check on the fo rego ing

computations, the gauge records a t Fryers Is land, about 6 mi les downstream,

were examined. The impact of the t e s t was c l e a r l y r e f l e c t e d i n t he hydrograph,

a t a l a g t ime o f t h i r t y minutes. From t h i s hydrograph, and t h e assoc ia ted

stage-discharge curve, t he a d d i t i o n a l volume o f water 'pas;ing through i F y e r s

6 3 I s l a n d dam was found t o be 4,090 cfs-hours (0.417 x 10 M ) , which compares

very s a t i s f a c t o r i l y w i t h the f i gu re computed a t S t . Jean. Table 3 summarises . :.

the Fryers I s l a n d l e v e l s and f lows data.

Mass curves were constructed f o r S t . Jean and Fryers I s l a n d f lows.

-. The d i f f e r e n c e between them showed, as the t e s t i n g proceeded, a steady and

gradual increase i n the volume of water en rou te through the i n t e r v e n i n g reach

o f the r i v e r (i .e. , below the shoal ) and i n .the canal. By the end o f t he

6 3 13:- hrs . t e s t per iod, an a d d i t i o n a l 6,370 cfs-hours (0.649 x 10 M ) o f water -.

* had been discharged a%t Fryers. I s l a n d whereas, as noted above, an a d d i t i o n a l

n e t 9,170 cfs-hours had been discharged a t S t . Jean. Thus the t r a n s i t o r y

a d d i t i o n a l "storage" was then 2,800 cfs-hours , approximately on&uarter o f

i t being i n the d i ve rs ion sec t i on of t h e canal and the. remainder i n the

r i v e r . With te rminat ion of t he d i version, the e x t r a s tored water r a p i d l y

dropped from t h i s peak t o zero dur ing the next 3 hours and f u r t h e r subsided

t o a minimum value of about minus 600 cfs-hours before being u l t i m a t e l y

d i ss ipa ted when t h e r i v e r had returned t o p re - tes t cond i t ions . This changing

p a t t e r n o f a d d i t i o n a l t r a n s i t o r y storage on the r i v e r was found t o r e l a t e

w e l l t o the changing l e v e l s recorded on t h e Fryers i s l a n d gauge.

A t the beginning and end of t he pe r iod o f nea r l y 27 hours on A p r i l 24-

25, t h e r i v e r f l ow was the same. This fo r tuna te l y permi t ted t h e assumption -..

o f a constant "base" f l ow from which changes, due t o t h e t e s t program, could

.- be r e a d i l y calculated, as described above. A s i m i l a r water balance ana lys i s

f o r the e n t i re per iod ~ p r i l 10-25, however, could n o t be c a r r i e d o u t because

the ou t f l ow from Lake Champlain d i d not remain constant dur ing these 16 days.

To est imate the a d d i t i o n a l volume o f water discharged dur ing t h i s complete

period. the r e s u l t s of t he A p r i l 24-25 t e s t were there fore used. The ne t

increase i n f l ow f o r the 7.0 and 8.4 ft. gate openings, as determined from

t h e t e s t , were app l i ed t o the t ime i n t e r v a l s f o r these ga'te openings du r ing

the A p r i l 10-20 per iod. Together w i t h the 4,220 cfs-hours passed dur ing

A p r i l 24-25, the t o t a l n e t a d d i t i o n a l water discharged dur ing t h e f u l l t e s t

6 3 per iod was found t o be 142,000 cfs-hours (14.48 x 10 M ) .

I n the Committee's view, the d i ve rs ion t e s t s were usefu l b u t very

l i m i t e d i n scope. The data obtained on A p r i l 24 from the sequence o f

increas ing openings of the guard gate are on ly ~ e r t i n e n t t o t h e r i v e r

discharge p r e v a i l i n g a t the t ime, i .e . , about 28,360 c fs ; d i f f e r e n t a r rays

o f r e s u l t s would have been obta ined w i t h smal ler o r g reater r i v e r f lows, such

as up t o 40,000 cfs o r more. Furthermore, even a t t h i s one p a r t i c u l a r r i v e r

discharge, the very important cond i t i on of maximum f l ow d i v e r s i o n was on ly

maintained f o r a pe r iod of 1 h r . 20 mins. For these reasons, t h e program was

too b r i e f and l i m i t e d i n range t o be adequate t o meet the o b j e c t i v e o f

t e s t i n g the s t r u c t u r a l and hyd rau l i c competency of t h e canal as a bypass

channel and the general f eas i b i l i t y of t h i s d i ve rs ion concept.

As p rev ious l y s tated, the ef fects of t h i s p a r t i c u l a r d i v e r s i o n t e s t

program i n 1979 were n o t detectable i n the recorded l e v e l s o f Lake Champlain.

I n order t o determine the order of magnitude o f any reduc t ion i n l ake l e v e l s

a t t a i n a b l e by t h e canal d i ve rs ion concept, a c0mpute.r s imu la t i on was made o f

t he maximum d i v e r s i o n t e s t con f igu ra t i on app l i ed t o t h e h i s t o r i c a l f l ow

record f o r 1970-1976. This was selected as i t was a pe r iod o f h igh water

supplies'. S p e c i f i c a l l y , i t was taken t h a t the d i v e r s i o n cou ld be operated

every year w i t h t h e guard gate f u l l y open dur ing the pe r iod A p r i l 1 t o

May 15. I t was assumed t h a t a longer pe r iod would be imprac t i ca l due t o i c e

cond i t ions before A p r i l and nav igat ion requirements a f t e r mid-May. I n the

mathematical model, the na tu ra l i n f l ows t o Lake Champlain f o r t he pe r iod 1970-

1976 were routed through the system w i t h a r a t i n g curve a t t he l a k e o u t l e t

r e f 1 e c t i n g 1975-1976 stage dis'charge cond i t ions modi f ied by such an annual

6-week d ivers ion . I n determining t h i s modif ied r a t i n g curve a t t h e lake,

r e s u l t s o f the d i ve rs ion t e s t were used t o c a l i b r a t e a mathematical model o f

the canal, which was then used t o e s t a b l i s h stages a t S t . Jean f o r f lows o the r

than the s i n g l e one p r e v a i l i n g dur ing the t e s t . This r a t i n g curve was then

t rans fer red t o the l ake by backwater ana lys is us ing the HEC-2 model. The

s h i f t i n the stage discharge curve due t o t h i s m o d i f i c a t i o n i s g rea te r a t

h igher flows. The l a k e l e v e l s produced were then compared w i t h those under

the 1975-1976 r a t i n g curve cond i t ions w i thout m o d i f i c a t i o n by d i ve rs ion .

Furthermore, i n order t o compare the lower ing of t he l ake l e v e l s by d i v e r s i o n

o f f lows through t h e canal w i t h t h e r a i s i n g o f l a k e l e v e l s apparent ly due t o

canal widening work i n the e a r l y 19701s, the same seven years o f Lake Champlain

na tu ra l i n f l o w s were rou ted through the systeni us ing the 1975-1976 r a t i n g

curve mod i f i ed by t a k i n g ou t t he canal widening e f f e c t .

This mod i f ied curve was determined by e s t a b l i s h i n g stage d ischarge

cond i t i ons a t t h e l a k e by backwater ana lys i s beginning below t h e shoal and

cons ider ing the r i v e r res to red t o i t s pre-widening s t a t e . The HEC 2 backwater

program was used c a l i b r a t e d w i t h 1975-1 976 cond i t ions .

F igure 5 i s a se r ies of annual hydrographs f o r t he pe r iod 1970-1976

showing the e f f e c t of a 6-week canal d i v e r s i o n opera t ion on t h e l e v e l s o f

Lake Champlain, computed as descr ibed above. It w i l l be seen t h a t ' the l e v e l s - -

would have been lowered f o r about t h ree months each year, commencing a t t h e

beginning o f A p r i l . Table 4 shows (a ) t he reduc t i on i n peak stage each s p r i ~ g ,

which var ies from 0.11 t o 0.29 feet, and (b ) t he maximum reduc t i on - occu r r i ng

several days o r weeks a f t e r the peak - which var ies from 0.20 t o 0.31 feet.

It appears from these r e s u l t s t h a t t he e f fec t of d i v e r s i o n f lows on l a k e ' l e v e l s

i s l a r g e l y dependent on the magnitude and t im ing o f t he s p r i n g peak. The

reduc t i on i n l e v e l s i s genera l l y g rea ter when the peak occurs l a t e r , i .e., when

the d i ve rs ion h a s been i n operat ion, lower ing l a k e l e v e i s , f o r a l onger p e r i o d

p r i o r t o t he peak. his suggests t h a t the d i v e r s i b n concept may be more

e f f e c t i v e if i t were poss ib le t o s t a r t i n mid-March each year i ns tead o f

A p r i l 1. Since t h e s h i f t i n t he stage discharge curve due t o canal d i v e r s i o n

i s g rea ter a t h ighe r flows, t he reduct ion i n peak l e v e l s i s genera l l y g rea te r

when the peak i s h igher .

F igure 6 i s a se r ies of annual hydrographs for t h e p e r i o d 1970-1976

showing the e f fec t o f t he canal widening on the l e v e l s o f Lake Champlain,

again co~iiputed as described above. I t w i l l be seen t h a t the widening, be ing

a f i xed phys ica l cond i t ion , would have r a i s e d the l ake l e v e l s a t a l l ' t imes,

- 12 -

over the e n t i r e range o f stage. Table 5 shows (a) the increase i n peak stage

each spr ing, which var ies from 0.25 t o 0.33 feet, and ( b ) t h e maximum increase

- occu r r i ng several days o r weeks a f t e r t he peak - which var ies from 0.29 t o

0.38 fee t . The general observat ions, p rev ious ly made, concerning the

r e l a t i o n s h i p between t h e magnitude and t i m i n g of t he sp r ing peak and t h e

magnitude of t he e f fec t of flow d ivers ion , a re s i m i l a r l y app l i cab le w i t h

regard t o t h e e f fec t o f canal widening.

Comparison o f the l a s t column i n Table 4 w i t h the l a s t column i n

Table 5 suggests t h a t the maximum reduct ions i n Lake Champlain l e v e l s t h a t

would have been achieved each year dur ing the h igh water pe r iod o f 1970-1976

by means o f a 6-week d i ve rs ion opera t ion would have o f fse t about 80% o f t h e

maximum increase a t t r i b u t a b l e t o the canal widening work.

I n order t o o b t a i n an order-of-magnitudk est imate o f t he kconomic

e f f e c t o f lower ing sp r ing l ake l e v e l s by means of an annual 6-week canal

d i ve rs ion operat ion, and t o compare t h i s w i t h an est imate o f t he economic

e f f e c t o f t he canal widening, the Ad Hoc Comnittee used the Board's w e l l -

documented eval ua t i o n methbdol ogy , w i thout mod i f i ca t i on . Ttii s inc luded t h e

same stage-damage curves fo r the l ake and r i v e r . The ana lys is , based on a

40-year pe r iod (1937-1976), showed t h a t t he canal widening increased average

annual damages by $091,400. The d i ve rs ion opera t ion would have p a r t i a l l y

o f f s e t these ef fects by a reduct ion i n average annual damages o f $559,500.

5. SUMMARY OF FINDINGS

The Ad Hoc Committe'e found the fo l lowing:

1. Parks Canada c a r r i e d out the d i ve rs ion t e s t dur ing t h e ~ p e r i o d

A p r i l 10-25. From A p r i l 10-20 c o n t r o l l e d f lows were passed through the canal

by opera t ing the sec tor guard gate. From 8 a.m. t o 4 p.m. on a d a i l y bas is

... /

the guard gate was se t a t an opening of 8.4 feet. From 4 p.m. t o 8 a.m. the

gate was set a t an opening of 7.0 feet. On A p r i l 24 flows were passed through

the canal t o t e s t a ser ies o f gate openings ranging from 2.0 f e e t t o f u l l

(50.0 feet ) .

2. Moni tor ing of condi t ions of canal flow was made fo l low ing a meeting

w i t h Parks Canada representat ives a t S t . Jean. The moni tor ing consisted o f

-.- water l eve l measurements a t s i x locat ions along the canal and measurement o f

canal discharge by standard cur rent metering procedures. Data were a lso - -

ava i lab le from the permanent gauges a t S t . Jean Marina and Frye-rs Island.

The f u l l moni tor ing program covered the A p r i l 24 tes t .

3. (a ) During the A p r i l 24-25 phase of the t e s t program, the

progressive increase i n the canal d ivers ion f low t o a maximum of. 2,285 c f s

was acconipanied by a corresponding progressive decrease i n the r i v e r f low t o . . . .

. .

a maximum o f 1,308 c f s . ~ h b natura l r i v e r discharge a t st. ~ & n a t t h i s t i m e . .

. . _ : . was 28,364 c fs .

. . . . . . . . . ' (b ) A w a t e r balance analysis. for t h i s per iod produced the -.

fo l lowing resu l t s :

cfs-hours

Volume o f water d iver ted through canal 19,630 Reduction i n wate.r over .the shoal. during. d ivers ion . .

. . : # . 10,460 . .

Reduction i n water over the shoal a f t e r d ivers ion 4,950 , . Total reduct ion i n water over the shoal 15,410

Net increase i n volume o f water passing S t . Jean . 4,220

(when water i s d iver ted through the canal, the upstream r i v e r l eve l i s

drawn down and the flow over the shoal i s therefore reduced. Upon abrupt

ten i i inat ion 'o f the canal flow, as i n t h i s t e s t program, the reduct ion i n f low

over the shoal pe rs is ts u n t i l the r i v e r recovers from the disturbance o f i t s

natural regime.)

4 . A water balance analys is fo r the e n t i r e t e s t period could not be

undertaken b u t , based on April 24-25 data , the net increase i n the volume of /

water discharged pas t S t . Jean i s estimated t o be approximately 142,000 c f s -

hours.

5. The e f f e c t s of the diversion t e s t were not detectable i n the

recorded l eve l s of Lake Champlain. I t i s therefore impossible t o measure the

-. - resu l t ing extremely small reduction in the acreage of flooded agr icu l tu ra l land

o r to make an economic evaluation of the t e s t .

. -. 6. Aside from some erosion below the sec to r guard gate due t o

turbulence when i t was in a pa r t i a l l y open posi t ion, and resu l t ing breakage of

a Hydro Quebec cable, no s t ruc tu ra l damage o r o ther appreciable erosion was

found as a r e s u l t of the t e s t s .

7. Using data obtained from the t e s t program, computer simulation of a

maximum discharge canal diversion operation from April 1 t o May 15 each year ,

under the high water supply conditions recorded in 1970-1976, indicates t h a t ,

during April t o June, lake l eve l s would have been lowered by up ' t o about

0.3 f e e t , which appears t o be roughly 80% of the ra i s ing e f f e c t inadvertently

caused by canal widening in the ea r ly 1970's. . . .

8. Using the ' ~ o a r d ' s evaluation methodol'ogy the' &conomic e f f e c t o f a

6-week diversion operation every year was estimated t o b e a reduction in

average annual damages in the order of $560,000. T h i s would p a r t i a l l y o f f s e t

an estimated increase i n average annual damages due t o canal widening of about

$890,000.

9. The t e s t program was extremely l imi ted. The change i n hydraulic

parameters in the canal under progressively increasing diversion flows were

only measured f o r a s i ng l e r i ve r discharge condition - one t h a t was not

unusual ly high fo r : the annual spr ing runoff. Moreover;' the maximum diversion

flow was only maintained f o r an hour o r so. F u l l prototype v e r i f i c a t i o n of

the hydrau l ic behaviour of the canal as a bypass channel was therefo-re n o t

obtained. Despite the Conanittee's attempt t o use the t e s t r esu l t s t o est imate

what a regular annual 6-week d ivers ion operation might achieve, i t must be

stressed t h a t the f i e l d tes ts were inadequate t o v e r i f y theore t i ca l hydrau l ic

computations, determine whether erosion o r o ther damages would render the

concept impract ica l or, i n general, prove the f e a s i b i l i t y o f the d ivers ion

concept. The Committee accordingly cautions against drawing any conclusions

from these tes ts as t o the mer i ts o f the canal d ivers ion concept.

TABLE 1

TEST DATA

DATE Guard Water Leve l E leva t i ons ( f t ) GSC Datum Mean l o c k Canal Gate v e l o c i t y Discharge

T IME, Opening St. Jean G a u g e No. ( h r s ) ( f t ) Mari na 1 2 3 4 5 6 ( f t pe r sec) ( c f s )

A p r i l 10 0.0 97.8 92.0 92.0 92.0

2.5 97.8 92.6 92.25

3.0 97.8 92.8 92.5

4.0 97.8 92.5

6.0 97.8 93.2 93.0

A p r i l 11

A p r i l 18 10:30 8.4

A p r i 1 24 08:OO 0.0

, . ."., l T i m e s shown a r e those o f gauge readings

~ e a n v e i o c i ty n b t measured, on1 y s i n g l e maximum r e a d i ng t a k e n (8.42 f t p e r sec)

3. I n t e r p o l a t e d v a l ue A t measur ing s e c t i o n

TABLE 2

LEVELS AND FLOWS AT ST-JEAN A p r i l 24-25

Di f fe rence f rom Water ove r Shoal Water th rough Canal T i m e "base" l e v e l a t Average D i f f e r e n c e f rom Vol ume Average Vo 1 ume Net Volume

I n t e r v a l s Mar ina gauge Flow "base" f l o w ( c o l . 1 x co1.4) f l o w ( c o l . 1 x co1.6) (co1.7 * co1.5)

( hours ) ( f t ) ( c f s ) ( c f s ) (c fs -hours ) ( c f s ) (c fs -hours ) ( c f s -hou rs )

1.47 -0.015 28,252 - 112 - 165 425 62 5 + 360 2.03 -0.030 28,139 - 225 - 457 714 1,449 + 992 2.70 -0.080 27,765 - 599 - 1,617 1,218 3,289 +1,672 1.21 -0.110 27,541 - 823 - 996 1,528 1,849 + 853 0.82 -0.130 27,391 - 973 - 798 1,711 1,403 + GO5 1.57 -0.150 27,242 -1,122 - 1,762 1,875 2,944 +1,182 2.37 -0.165 27,131 -1,233 - 2,922 2,123 5,032 +2,110 I

1.33 -0.175 27,056 -1,308 - 1,740 2,285 3,039 +1,299 0.60 -0.080 27,765 - 599 - 359 0 0 - 359 A

0 0 U

1.00 -0.080 27,765 - 599 - 599 - 599 1.00 -0.075 27,803 - 561 - 561 0 0 - 561 I

1.00 -0.070 27,840 - 524 - 524 0 0 - 524 1.00 -0.065 27,877 - 487 - 487 0 0 - 487 1.00 -0.060 27,914 - 450 - 450 0 0 - 456 1.00 -0.050 27,989 - 375 - 375 0 0 - 375 1.00 -0.050 27,989 - 375 - 375 0 0 - 375 1.00 -0.045 28,027 - 337 - 337 0 0 - 337 1.00 -0.040 28,064 - 300 - 300 0 0 - 300 1.00 -0.035 28,102 - 262 - 262 0 0 - 262 1.00 -0.025 28,177 - 187 - 187 0 0 - 187 1.00 -0.015 28,252 - 112 - 112 0 0 - 112 0.73 -0.005 28,327 - 37 - 2 7 0 0 --- - 27

26.83 -15,412 19,630 4,218

TABLE 3

LEVELS AND FLOWS AT FRYERS ISLAND A p r i l 24-25

T i me I n t e r v a l s

D i f fe rence f rom "base" 1 eve1 . a t Fryers I s . gauge

Average D i f f erence from F low "base" f l o w

Vol ume ( c o l . 1 , . x co1.4)

( hou rs ) ( f t ) ( c f s ) ( c f s ) (c fs-hours)

0.83 +O. 005 28,624 + 40 + 33 1.00 +O. 015 28,702 + 118 +I18 1.00 +0.023 28,768 + 184 +I84 1.00 +O. 031 28,834 + 250 +250

8' 1.00 + O . 044 28,939 - + 355 +355 1.00 +0. 054 29,018 + 434 +434 1.00 +O. 057 29,044 + 460 +460 1.00 +O. 066 29,110 + 526 +526 1.00 +O. 079 29,215 + 631 +631 I

1.00 +O. 089 29,294 + 710 +710 1.00 +O. 095 29,347 + 763 +763 --I

1.00 03

+O. 103 29,413 + 829 +829 1.00 +O. 113 29,492 + 908 +908 I

0.17 +O. 121 29,557 + 973 +I65 0.50 +O. 130 29,622 +1,038 +519 0.33 +O. 1 2 1 29,557 + 973 +324 1.00 +O. 061 29,071 + 487 +48 7 1.00 -0.005 28,545 - 39 - 39 1 .00 -0.033 28,321 - 263 - 263 1.00 -0.046 28,215 - 369 - 369 1.00 -0.049 28,139 - 395 - 395 1.00 -0.048 28,202 - 382 - 382 1.00 -0.046 28,215 - 369 - 369 1.00 -0.046 28,215 - 369 - 369 1.00 -0.044 28,229 - 355 - 355 1.00 -0.043 28,242 - 342 - 342 1.00 - -0.041 28,255 - 329 -329 1.00 -0.034 28,308 - 276 -276 1.00 -0.015 28,466 - 118 -118 -

26.83 4,090

TABLE 4

COMPUTED EFFECTS OF CANAL DIVERSION ON LAKE CHAMPLAIN LEVELS ( f e e t , U.S.G.S. Datum)

EFFECT ON MAXIMUM LAKE STAGE

MAXIMUM EFFECT ON LAKE STAGES

Level Level Reduction Level Level Reduction YEAR DAY w i t h o u t w i t h i n l e v e l DAY w i t h o u t w i t h i n l e v e l

d i vers i on d i ve rs ion d i vers ion d i v e r s i o n

1970 May 1 100. 91" 1 00. 7.1 .20. May 13 100.03 99.74 .29

1971 May12 101.47 101.18 - 2 9 May 16 101.28 100.97 .31

I

1972 May 10 101.66 101.42 .24 May14 101.52 101.23 .29 -.I

a

1973 Apr 8 100.51 100.37 .14 Apr 30 99.25 98.96 .29 I

1974 May 3 100.27 - 100.03 .24 May 16 100.15 99.84 .31

1975 Apr 28 99.33 99.22 .ll May 10 99.05 98.85 - 2 0

1976 Apr '6 101.46 101.34 .12, May 8 99.13 98.83 .30

TABLE 5

COMPUTED EFFECTS OF CANAL WIDENING ON LAKE CHAMPLAIN LEVELS ( f e e t , U.S.G.S. Datum)

EFFECT ON MAXIMUM LAKE STAGE MAXIMUM EFFECT ON LAKE STAGES

-- Leve l Leve l I nc rease

YEAR DA Y w i t h o u t i n l e v e l Leve l

w i t h Leve l I nc rease

DAY w i t h w i t h o u t i n l e v e l w iden ing w iden ing w iden ing w iden ing

May 1 May 20

May 12 May 30 99.60

May 10 101.35 t

Jun 1 99.22 99.58 .36

Apr 8

May 3 99.95

May 6 98.88

1976 Apr 6 101.17 101.46 .29 Apr 28 99.05 99.41 , . 3 6

\ - R/CHEL/EU RIVER btL I UK bUARD GATE

TEMPORARY CHANNEL F I L L

CANAL

- - - EN TRANCE ST J E A N MARINA GAUGE WATER SURVEY OF CANADA

------_ ST NO 020J016 - _

--------

STRUCTURE

CITY OF ST JEAN

105 - I*" '7 105 - ELEV 100 0

ELEV 99 0

95 - 95 - F x

9 4

r d 6

', b

1 t

85 - 85 - . SECTION B - B LOCATION OF wnr t~ L ~ V ~ L M ~ A ~ U H E M E N T S SECTION A - A

50 0 10 5 0 5 0 0 10 50

SCALE IN FEET SCALE IN FEET

CHAMBLY CANAL DIVERSION TEST PLAN VIEW OF TEST SECTION

200 100 0 100 200 300 400 500 I T I I t 4

SCALE IN F E E T FIGURE I

- - - - - - - 98 - - - - GUARD GATE OPENING FULL 50 .0 ' FLOW 2285 cfs - - -

A - - - - GUARD GATE OPENING 28.0 ' FLOW 2123 c f s

96 - - - - - GUARD GATE OPENING 16.0' FLOW 171 1 c f s - - -- 0 - --

-I

GUARD GATE OPENING 8.4' FLOW 1218 cfs -- - - - - - - 94

GUARD GATE OPENING 4.0' FLOW 714 cfs , L

0 9 2 --

I

- OUTLET STRUCTURE

P GAUGE LOCATIONS

WATER LEVEL READINGS

_9 GUARD

Q- GATE

CHAMBLY C A N A L D IVERSION T E S T

TYPICAL WATER SURFACE P R O F I L E S

SCALE IN FEET 400 200 100 0 200 400

FIGURE 2 1

CANAL GUARD GATE

Gate opening of 8.4 feet Flow 1218 cfs

Gate opening 16.0 feet Flow 1711 cfs

FIGURE 3

OUTLET STRUCTURE

View looking upstream at exit

Flow conditions of 1875 cfs

FIGURE 4

o LAKE CHRMPLRIN STRGE HYDROGRRPH 1973 0

m EFFECT OI I CAf lAL DIVERS IOY APRIL 1 - 1 5 M Y

cn a JAN FEB MAR APR NA'I JUN JLY RUG .' ' . SEP O C T N O V ' D E C

o LnKE CHRMPLRIN STAGE HYDROGRRPH 1974 0

EFFECT O N CAML DIVERSI'IIq AP!IIL 1 - MAY 15

cn a) JAN FEE M A R APR MAY JUN JLY AUG SEP O C T NOV DEC

o LRKE CHAMPLAIN STRGE HYDROGRAPH 1975 EFFECT O!J CANAL DIVERSIOII APRIL 1 - MAY 15

J A N FEB MAR A P R M A ' I J U N JLY R U G - SEP OCT N O V DEC

cn J A N FEB MAR A P R MAY EI, JUN - JLY A i l 0 SEP OCT N O V DEC

0 Lf lKE CHAMPLAIN STQGE HYDROGRAPH 1971 EFFECT OF CANAL WIDENING

m 0- 9 FEB MAR APR MAY JUN JLY AUG SEP O C T NOV DEC

LRKE CHRMPLRIN STRGE HYDROGRAPH 1973

EFFECT OF CANAL W IDEIIIMG

rn n JAN FEB MAR APR HAY JUN - S E P . , OCT NOV , OEC

o LAKE CHAMPLAIN STAGE HYDROGRAPH 1974 0

EFFECT OF CANAL WIDEN I tJG

JAN " FEB' MAR APR . . ' HAY JUN' JLY RUG SEP OCT NOV DEC

LAKE CHAMPLRIN STRGE HYDROGRAPH 1975 EFFECT OF Cg41JAL WIDEN I t lG

or + JAN FEB MAR APR M A Y JUN JLY RUG SEP OCT NOV DEC

INTERNATIONAL JOINT COMMISSION

COMMISSION MIXTE INTERNATIONALE

File: 98-7-11:1 100 RUE METCALFE STREET OTTAWA, ONTAKIO

19 April 1979 K I P 5Ml

\

Mr. H.B. Rosenberg Chairman, Canadian Section ~nternational Champlain-Richelieu Board

Dear Mr. Rosenberg:

This will confirm our recent telephone discussion concerning the Commission's request that the Board form an ad-hoc committee to monitor the flow through the Chambly Canal at St. Jean, Qugbec. You and Terrence Curran concurred with the suggested appointments of Art Ellis, Peter Reynolds,'John Bathurst, Sam Tosi, Jesse Rosen and Dick Griffith. Messrs. Bathurst and Griffith will serve as co-chairmen of the ad-hoc committee.

- The Commission was advised by the Government of Canada by letter dated 23 March 1979 that the Canal would be used to pass additional water this spring during the high supply period

- to offset, to some degree, the restriction caused by the widening of the Chambly Canal and to improve conditions for the farmers in the Richelieu Valley above St. Jean. The Board is requested to monitor the hydraulic effects of the program and the effect on

- the agricultural lands in Qugbec.

With respect to the hydraulic effects the Board should - ensure that sufficient data are gathered during the tests to

permit a determination of the flow in the Chambly Canal and the change in the water levels of the Richelieu River and Lake Champlain. With respect to the resultant change in the River profile on the - agricultural lands in Quebec, the reduction in flooded farm acreage in Quebec should be determined.

- In view of the short duration of the increased flows, which I understand are now scheduled to be completed by May 1, your

# immediate advice is requested concerning the data collection program - required, including aerial overflights, if necessary, to adequately

determine such effects. J

Mr. H.B. Rosenberg 19 April 1979

The Commission has advised the Canadian and United States Governments of its intention to monitor the above flows. A copy of the Commission's letter is enclosed.

A similar letter has been sent to the United States Chairman of the International Champlian-Richelieu Board by the Engineering Advisor of the United States Section of the Commission.

Y0ur.s very truly,

MWT : ds Encl.

cc: Mr. S.N. Hodgson Mr. B. Beauprg Mr. J-R Roy Mr. Art Ellis Mr. Peter Reynolds Mr. John Bathurst Mr. R.H. Millest Mr. D.G. Chance Dr. M. Clamen Mr. S.H. Fonda