TECHNICAL REPORT OF THE COMMI?TEE

-- -- --

Regulation of Lake Champlain and the

1 Upper Richelieu River TECHNICAL REPORT OF THE PHYSICAL ASPECTS COMMI?TEE

COVER PHOTOGRAPHS

Top: Flooded approach to ferry dock on Lake Champlain (Net Benefits Com- mittee)

Centre: Seining for pike fry (Environmental Impact Committee)

Bottom: Model testing of a reach of the Richekieu River (Physical! Aspects Committee)

I N T E R N A T I O N A L C H A M P L A I N - R I C H E L I E U EOARD

T E C H N I C A L REPORT

OF THE

P H Y S I C A L ASPECTS COMMITTEE

December 1 977

2 9 November 1977

Mr . H.B. R o s e n b e r g , Co-Chairman Canad ian S e c t i o n M r . T.P. C u r r a n , Co-Chairman U.S. S e c t i o n I n t e r n a t i o n a l Champla in R i c h e l i e u Board

Gent lemen:

T r a n s m i t t e d h e r e w i t h i s t h e f i n a l r e p o r t o f t h e P h y s i c a l A s p e c t s Committee c o n t a i n i n g t h e r e s u l t s and d e s c r i p t i o n o f o u r i n v e s t i g a t i o n i n t o t h e f e a s i b i l i t y o f c o n s t r u c t i o n o f c o r r e c t i v e works on t h e R i c h e l i e u R i v e r i n Canada . T h i s r e p o r t h a s b e e n p r e p a r e d i n r e s p o n s e t o t h e c h a r g e g i v e n t h i s Committee u n d e r d a t e o f J u l y 11, 1 9 7 5 .

R e s p e c t f u l l y s u b m i t t e d ,

A r t h u r L . E l l i s (Co-Chairman)

( < <

J e y e o s e n (Co -Cha i rman) < __- k

1 R o b e r t L a v a l l e e

./.,,.

John E . C e r u t t i

d&,,'{L~- A&-- B e n e d e t t o R i z z o :' 1

PHYSICAL ASPECTS COMMITTEE

A r t h u r L. E l l i s (Co-Chairman) Env i ronment Canada, Ot tawa, Ont.

Jesse Rosen (Co-Chairman) U.S. Army Corps o f E n g i n e e r s , New York , F1.Y.

R o b e r t Lava1 1 ee M i n i s t P r e des R i chesses n a t u r e l l e s , QuPbec, Que.

A1 l a n Tedrow New York S t a t e Depar tment o f E n v i r o n m e n t a l ~ o n s e r v a ' t i o n , A lbany , N . Y .

John C c r u t t i Vermont Depar tment o f !dater Resoi lrces, I l o n t p e l i e r , V t .

Renede t to Ri zzo U.S. F i s h and W i l d l i f e S e r v i c e , Newton, Mass.

ACKNOWLEDGEMENTS

The Commit tee w ishes t o acknowledge t h e a d v i c e and s e r v i c e s o f t h e s t a f f s o f t h e agenc ies r ~ p r e s e n t e d on t h e Committee, o t h e r government agenc ies i n b o t h c o u n t r i e s and p r i v a t e i n d i v i d u a l s and o r g a n i z a t i o n s who c o n t r i b u t e d t o t h e s t u d i e s .

(iii)

TADLE OF COIITE?!TS ...-.

Page

....................... SUMMARY. CONCLUSIONS AND RECOPiMEI4DATIONS 1

Sec t i on 1 . INTRODUCTION

1.1' Nature of Problem .............................................. 6 1.2 Charge t o Committee ............................................. 6 1.3 Prev ious Work .................................................. 10 1 .4 Other Cornnii t t e e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Sec t i on 2 . GEYERAL

2.1 Bas in D e s c r i p t i o n .............................................. 2.2 Hydro logy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2.1 C l ima te ................................................. .................................................. 2.2.2 Runof f

2.2.3 Lake Leve ls .............................................. 2.3 H y d r a u l i c Analyses .............................................

................................ 2.4 Regu la t i on Analyses Methodology 2.5 F i e l d S tud ies ..................................................

......................................... 2.6 Phys i ca l Model S tud ies .................................................. 2.7 Cost C r i t e r i a

............................................ 2.8 Regu la t i on C r i t e r i a

Sec t i on 3 . CHANNEL EXCAVATION

3.1 General ........................................................ 25 3.2 Excavat ion Dimensions ........................................ 25

........................ 3.3 Excavat ion Procedures ................. ' 29 ................................. 3.4 Impacts on Ad jacent S t r u c t u r e s 29

3.5 Costs .......................................................... 30 . .

Sec t i on 4 . FIXED CREST STRUCTURE

..................... ...................... 4.1 .General D e s c r i p t i o n ; 33 .............................................. 4.2 .Geo log ic Features 33

........................................... 4.3 Phys i ca l Model Tests 33 4.4 Regu la t i on Analyses ............................................ 40

............................. 4.5 Impact o f S t r u c t u r e on Lake Leve ls 40 4.6 Cons t ruc t i on Procedures ........................................ 40 4.7 Cost Est imates ................................................. 45

Sec t i on 5 . NEW GATED STRUCTURE

5.1 G e n e r a l D e s c r i p t i o n ..................................... .- . . ..... 51 5.1.1 S i t e Loca t i on . ......................................... 51 5.1.2 S t r u c t u r e ............................................... 51

................................................... 5.1.3 Gates 51 5.2 Geologic Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Page-

5 .3 P h y s i c a l Model T e s t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 I?c?cll-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 1 1 i l ~ ~ t c t o f I ; t . ructurc on I.ilkc> I-clvels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.6 C o n s t r u c t i o n Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 5.7 Cos t E s t i r ~ i a t e . .. . .. . . . . . . . .. . . . . . . . . . . . . .. . . .. . . . . . . . . . . . . . . . 75

S e c t i o n 6 - FRYERS ISL414D DAM

6.1 Genera l D e s c r i p t i o n . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 81 6.2 R e g u l a t i o n Ana lyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 6.3 I m p a c t o f F r y e r s I s l a n d Dam on Upstream L e v e l s . . . . . . . . . . . . . . . . . 81 6 .4 D y k i n g and D r a i n a g e Works ...................................... 87

6.4.1 Need f o r Dykes and D r a i n a g e Works ....................... 87 6.4.2 D r a i n a g e C r i t e r i a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6 . 4 . 3 D-ykes and W a l l s ......................................... 87 6.4.4 D r a i n a g e Systems ........................................ 88

6.5 C o n s t r u c t i o n Procedures ........................................ 8 8 6 .6 Cos t E s t i m a t e s ................................................. 88

S e c t i o n 7 - LAKE LEVEL TREND STUDIES

7.1 Genera l . . . . . . . . . . . . . ;. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 7.2 E v i d e n c e o f Lake L e v e l T rends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 7.3 P o s s i b l e Causes o f T r e n d i n g ... ... .... .. .......... .. .... ...... .. 102 7.4 I n v e s t i g a t i o n o f P o s s i b l e Causes ............................... 107

7.4.1 D a t a A n a l y s i s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 7.4.2 C r u s t a l Movement ........................................ 107 7.4.3 S e d i h e n t a t i o n . .-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

., . . 7.4.4 Canal \ J i d e n i n g . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . ... . . . ,108 7.4.5 A q u a t i c V e g e t a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 8 7.4.6 C l i m a t e ................................................. 109

7.5 C o n c l u s i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

S e c t i o n 8 - OTHER STUDIES AND ANALYSES

8.1 F l o o d P r e d i c t i o n Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8 .1 .1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.1.2 U.S. N a t i o n a l Weather S e r v i c e P r e d i c t i o n Model .......... 110 8.1.3 Use o f Model i n R e g u l a t i o n S t u d i e s . . . . . . . . . . . . . . . . . . . . . . 110

8 . 2 Use o f 1976 S tage D i s c h a r g e R e l a t i o n s h i p . . . .. . . . . .. . . . . . . . . . . . . 111 8 .3 Downs t rean i E f f e c t s o f R e g u l a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 1

LIST OF TABLES

R e g u l a t i o n Schemes Lake L e v e l Data f o r R e g u l a t i o n Schemes Economic A n a l y s i s o f R e g u l a t i o n Schemes Summary o f E s t i m a t e d Cos ts f o r D r e d g i n g D e t a i l e d Cos t E s t i m a t e f o r D r e d g i n g Summary o f C o s t E s t i m a t e - F i x e d C r e s t S t r u c t u r e D e t a i l e d Cos t E s t i m a t e - F i x e d C r e s t S t r u c t u r e Summary o f E s t i m a t e d Costs - Gated C o n t r o l S t r u c t u r e D e t a i l e d Cos t E s t i m a t e - Gated C o n t r o l S t r u c t u r e Summar~y o f E s t i m a t e d Costs - Fr.yers I s l a n d Cam P r o p o s a l D e t a i l e d C o s t E s t i m a t e - F r y e r s I s l a n d Dam P r o p o s a l T r e n d A n a l y s i s , Annual Maximum Mean D a i l y L e v e l s T r e n d A n a l y s i s , Annual Minimum Mean D a i l y L e v e l s R a t i n g Curve Changes, Lake L e v e l s A s s o c i a t e d w i t h R i c h e l i e u R i v e r F lows

LIST OF FIGURES

D r a i n a g e B a s i n Genera l L o c a t i o n P l a n Water S u r f a c e P r o f i 1 e f o r N a t u r a l Channel Frequency Curve - Maximum D i s c h a r g e f o r R i c h e l i e u R i v e r a t F r y e r s Rap ids Frequency Curve - Minimum D i s c h a r g e f o r R i c h e l i e u R i v e r a t F r y e r s Rapids Frequency Curve - Extreme H i g h s f o r Lake Champla in L e v e l s a t Rouses P o i n t Frequency Curve - Mean Lows f o r Lake Champla in L e v e l s a t Rouses P o i n t H i s t o r i c a l Hydrographs f o r Lake L e v e l s - USGS L o c a t i o n o f B o r e h o l e s P l a n and P r o f i l e - Dredged Channel E f f e c t o f D r e d g i n g on Lake Champla in L e v e l s Water S u r f a c e P r o f i 1 e f o r Dredged Channel P lan , E l e v a t i o n and S e c t i o n - F i x e d C r e s t S t r u c t u r e P a r t i a l View - Proposed F i x e d C r e s t S t r u c t u r e a t S t . Jean Pho tograph o f S i t e L o c a t i o n - F i x e d C r e s t S t r u c t u r e G e o l o g i c a l P r o f i l e - F i x e d C r e s t S t r u c t u r e S i t e Wate r S u r f a c e P r o f i l e f o r Dredged Channel w i t h Fired C r e s t S t r u c t u r e Lake .Champla in S tage - D i s c h a r q e R e l a t i o n s h i p f o r F i x e d C r e s t laleir a t C4 Lake Champla in S tage Hydrograph f o r a Low Year - WR Scheme Lake Champla in S tage Hydrograph f o r a H i q h Year - WR Scheme Lake Champla in S tage Hydrograph f o r a Normal Year - WR Scheme D u r a t i o n A n a l y s i s f o r WR Scheme C o n s t r u c t i o n Schedu le - F i x e d C r e s t S t r u c t u r e Gated S t r u c t u r e Genera l Arrangement Gated S t r u c t u r e - P l a n , E l e v a t i o n and S e c t i o n P a r t i a l View - Proposed Gated S t r u c t u r e a t S t . Jean Gated S t r u c t u r e - Pho tograph o f S i t e L o c a t i o n Pho tograph - S t . Ours Dam G e o l o g i c a l P r o f i l e - Gated S t r u c t u r e S i t e

( v i i )

Lake Champla in S taqe - D i s c h a r g e R e l d t i o n s h i [ ) Gated S t r u c t u r e a t C27 Water S u r f a c e P r o f i l e f o r Gated S t r u c t u r e Lake Champla in S tage Hydrograph f o r a Low Year - FCE-1 Scheme Lake Champla in S t a g e Hydrograph f o r a H i g h Year - FCE-1 Scheme Lake Charnplain S taqe Hydrograph f o r a Normal Year - FCE-1 Schene Lake Champla in S taqe Hydrograph f o r a Low Year - FCE-2 Scheme Lake Champla in S taqe Hydrograph f o r a H i q h Year - FCE-2 Scheme Lake Champla in S tage Hydrograph f o r a Normal Yedr - FCE-2 Scheme - Lake Champla in S tage Hydrograph f o r a Low Year - FCE-3 Scheme Lake Champla in S t a g e Hydrograph f o r a H i q h Year - FCE-3 Scheme Lake Champla in S tage Hydrograph f o r a Normal Year - FCE-3 Scheme D u r a t i o n A n a l y s i s f o r FCE-1 Scheme D u r a t i o n A n a l y s i s f o r FCE-2 Scheme D u r a t i o n A n a l y s i s f o r FCE-3 Scheme C o n s t r u c t i o n Schedu le - Gated S t r u c t u r e Pho tograph - F r y e r s I s l a n d Dam F r y e r s I s l a n d Dam - Plan, E l e v a t i o n and S e c t i o n Lake Champla in Stage- D i s c h a r g e R e l a t i o n s h i p F r y e r s I s l a n d Dam O p e r a t i o n Wate r S u r f a c e P r o f i l e f o r F r y e r s I s l a n d Dam L o c a t i o n o f D y k i n g and D r a i n a g e Works T y p i c a l S e c t i o n s - D y k i n g and D r a i n a g e Works Lake Champla in S tage Hydrograph f o r a Low Year - FCE-4 Scheme Lake Champla in S taqe Hydrograph f o r a H i g h Year - FCE-4 Scheme Lake Champla in S tage Hydrograph f o r a Normal Year - FCE-4 Scheme D u r a t i o n A n a l y s i s f o r FCE-4 Scheme C o n s t r u c t i o n Schedu le - D y k i n g and D r a i n a g e Works and F r y e r s I s l a n d

Dam R e n o v a t i o n s Compar ison o f S t a g e - D i s c h a r g e R e l a t i o n s h i p s f o r Gated S t r c u t u r e and

N a t u r a l Range S y n t h e t i c Vs N a t u r a l Lake L e v e l s

REFERENCES

CONTRACTORS REPORTS AND SUPPORTING DATA

( v i i i )

Page

59 61 6 3 64 6 5 5 6 67 63 6 3 70 7 1 7 2

SUMMARY, CONCLUSIONS AND .RECOMMENDATIONS

The Physical Aspects Committee (PAC) car r ied out s tud ies t o determine engineering f e a s i b i l i t y , costs and impact on water l eve ls of th ree s t ruc tura l a l t e rna t i ve s fo r lake level regulation. The Committee concluded t h a t a s t ruc tura l solut ion together with channel dredging i s economically j u s t i f i e d and can meet the object ives of reducing flooding on the Richel ieu River and Lake Champlain while s a t i s fy ing c r i t e r i a establ ished t o pro tec t the natural- environment.

The appl i cab le f i na l management c r i t e r i a addressed by the Committee a r e Schemes FCE-1, 2, 3 and 4, a1 1 having a requirement f o r 40 day lake level duration a t e levat ion 98.5, 98.0, 97.5 USGS respect ively. Scheme FCE-4 has the same management c r i t e r i a a s Scheme FCE-3.

Channel dredging common t o a l l s t ruc tura l schemes can be accomplished a t a cos t of $ 3 . 3 million f o r a length of 8,000 f e e t through the shoal a t S t . Jean.

A fixed c r e s t s t r uc tu re can be constructed a t a locat ion between t he Gouin and C P R bridges a t Saint Jean a t a capi tal cos t of $4.6 million. No regulation management i s possible; however the s t ruc tu re meets the management c r j t e r i a f o r Schemes FCE-2 and 3. Analyses of performance ind ica te t h a t a benefi t co s t r a t i o of 3.25 can be expected from these works.

A new gated s t ruc tu re can be constructed a t a location 3,000 f ee t downstream of s t s ranging between $1 2.3 and $1 2.8 mi 11 ion. owever, t o meet management c r i t e r i a , Schemes

analyses of these Schemes ind ica te benefi t cost r a t i o s of 1.84, 1.86 and 1.90 respect ively.

The ex is t ing Fryers Island Dam can be u t i l i z ed a t a cap i ta l cost of $9.9 mil l ion. Various regulation plans a re possible; however, only Scheme FCE-4 i s . appl icable . Economic analysis of t h i s proposal y ie lds a benefi t cos t r a t i o of 2.05 excluding navigation benefi ts .

There a r e l i ke ly a number of contr ibut ing causes t o the upward trending of the stage-discharge re la t ionsh ip of Lake Champlain. The primary cause i s probably the

I t i s the opinion of t h i s Committee t ha t a fixed c r e s t s t r uc tu re does not o f f e r

m F m M t - l P m - 1 = r n m g ~ . However , the

/

Due t o the nature of the ~ r e s e n t invest iqat ion. the ~ h v s i c a l ~ s p e c t s Committee

be conducted t o t e s t the loads on the sec tor gates fo r s t a b i l i t y - a n d s t ruc tura l i n t eg r i i y . For construction of e i t h e r the weir o r dam a t Saint Jean, i t i s recommended t h a t a model be constructed t o determine whether temporary channel bottom protection i s required fo r the channel openings with cofferdams in place. I t i s f u r the r recommended t h a t a r i ve r

model be cons t ruc ted t o t e s t t h e cofferdam and p l u g arrangements again. T h i s l a t t e r s tep i s necessary because i t was determined by a new channel survey ( a f t e r t h e PAC model s tudy was f i n i s h e d ) t h a t t h e o r i g i n a l work was done us ing a channel bot tom approximately two f e e t t o o h igh.

Fo l l ow ing t a b l e s summarize data on r e g u l a t i o n schemes.

T A B L E 1

REGULATION SCHEMES

TYPE OF REGULATION SCHEME MINIFRJM LAKE M I N I M U M LAKE ENVIRONMENTAL REQUIRED CREST

L STRUCTURE IEENTI FICATION LEVEL (USGS) OUTFLOW CFS TARGET (USGS) LEVEL (USGS)

Gated S t r u c t u r e o r NF

Fryers I s l a n d Dam FC

I

- ( Gated S t r u c t u r e FCE-2 . 9 X O 3,000 1 9 8 . 0 - 4 0 d a y s 1 94.35

Fixed-Crest Weir WR 93.20

MP 94.0 94.35

I FCE-3 95.0 3,000 97.5 - 40 days \ 93.35

Fryers I s l a n d Dam

T A B L E 2

LAKE LEVEL DATA FOR REGULATION SCHEMES

DAILY MEANS

Long-Term Average - April 5 (USGS)

Long-Term Average - April 15 (USGS)

Long-Term Average - May 15 (USGS)

Long-Term Average - June 10 (USGS)

SPRING AND SUMMER '

Long-Ten Average Rise - April 5 t o May 15 (Feet)

Long-Term Average Fall - April 16 t o June 10 (Feet)

Long-Term Average Peak - March 1 t o June 30 (Feet)

FALL AND WINTER

Long-Term Average Rise - October 1 t o March 1 (Feet)

Long-Ten Maximum Rise - October 1 t o March 1 (Feet)

Long-Term Monthly Mean - March (USGS)

Long-Term Monthly Mean - October (USGS)

M E ELEVATION (USGS) SATISFYING ENVIRONMNTAL

DUWLTION (40 DAYS) CRITERIA

SO(EM IOENTIFICATION

>

NATURAL (SYNTHETIC)

97.88

98.59

98.82

97.60

1.89

1.27

' 99.79

' 0.93

'. 2.14

96.25

94.83

WR

97.38

97.90

97.76

96.69

1.47

1.40

98.87

0.83

1.99

95.94

94.67

97.90

UP

96.49

97.03

97.02

95.77

1.60

1.50

98.12

0.21

1.24

95.21

94.61

NF

96.87

97.33

97.44

96.62

1.47

0.96

98.39

0.85

1.99

95.88

94.99

FC

96.78

97.40

97.54

96.68

1.70

0.99

98.50

0.20

1.24

95.33

94.61

F1

96.94

97.49

97.55

96.67

1.61

1.07

98.57

0.84

1.99

95.80

94.99

FCE-1

97.00

97.56

97.93

97.13

1.61

0.78

98.63

0.35

1.37

95.69

94.88

98.50

FCE-2

97.00

97.57

97.86

97.08

1.60

0.82

98.62

0.36

1.38

95.69

94.87

98.00

FCE-3

96.98

97.55

97.73

96.91

1.61

0.91

98.61

0.46

1.49

95.65

94.73

97.50

FCE-4

96.89

97.40

97.48

96.50

1.53

1.13

98.45

0.44

1.44

95.65

94.81

97.50

I I ECONOMIC ANALYSIS OF REGULATION SCHBmS

(All finuies for benefits and costs are in-thousands of dollars1

SCHBhE IDENTIFICATION /

SECTION 1 INTRODUCTION

1.1 Nature o f Problem

Lake Champlain, l y i n g a long t h e borders of New York and Vermont, covers an area o f 6 square m i l - I t d r a i n s northward through t h e R i c h e l i e u R i v e r a t Rouses Po in t , N.Y.,

%to t h e Prov ince of Quebec, d i scha rg ing i n t o t h e S t . Lawrence R i v e r a t Sore1 , Que. (see F igu re 1 ) .

The ou t f l ow o f t h e lake, th rough t h e R i c h e l i e u River , i s c o n t r o l l e d by a n a t u r a l shoal a t S a i n t Jean, Que. Th is shoal , l o c a t e d about twenty- three m i l e s f rom t h e i n t e r - n a t i o n a l boundary, forms a n --&he1 u i e u R i v e r and Lake Champlain upstream (see F igures 2 and 3 ) . The shoal r e s t r i c t s o u t f l o w and d u r i n g pe r iods o f excess ive r u n o f f causes f l o o d i n g on low l y i n g areas around t h e l a k e and a long t h e r i v e r . H igh water l e v e l s on Lake Champlain and the R i c h e l i e u R i v e r have caused cons iderab le p r o p e r t y and a g r i c u l t u r a l damages which, i n t u r n , have l e d t o numerous compla in ts and requests f o r r e l i e f . Dur ing t h e 1930 's t h e governments o f Canada and t h e U n i t e d Sta tes entered i n t o d iscuss ions, t h e r e s u l t o f which was t o r e f e r t h e f l o o d i n g problem f o r s tudy by the I n t e r n a t i o n a l J o i n t Commission ( I JC) under the Boundary Waters T r e a t y o f 1909.

A s tudy was subsequent ly conducted and, i n 1937, t h e IJC approved t h e c o n s t r u c t i o n and o p e r a t i o n by Canada o f remedial works i n t h e R i c h e l i e u R i v e r i n t h e v i c i n i t y o f S a i n t Jean, Que. The proposed works cons i s ted of channel dredging, dyk ing and t h e const ruc- t i o n of a c o n t r o l dam a t Fryers I s l a n d . The Fryers I s l a n d Dam was completed i n 1939. The assoc ia ted channel dredging and dyk ing was never undertaken. Therefore, e f f e c t i v e r e g u l a t i o n o f t h e R i c h e l i e u R ive r f o r f l o o d c o n t r o l and o t h e r purposes was n o t achieved.

H igh water du r ing r e c e n t years spurred t h e Prov ince o f Quebec t o f u r t h e r examine p o s s i b l e r e g u l a t i o n o f t h e upper R i c h e l i e u R ive r . The problem was again r e f e r r e d t o t h e IJC i n March 1973 by t h e two federal governments. The IJC was requested t o i n v e s t i g a t e and r e p o r t upon t h e f e a s i b i l i t y and d e s i r a b i l i t y o f r e g u l a t i n g t h e R i c h e l i e u R i v e r f o r t h e purpose o f a l l e v i a t i n g extreme water c o n d i t i o n s i n t h e R i c h e l i e u R ive r and Lake Champlain, and f o r o t h e r b e n e f i c i a l purposes. The I n t e r n a t i o n a l Champlain-Richel ieu Engineer ing Board s e t up t o conduct t h e f e a s i b i l i t y s t u d i e s subsequent ly repo r ted back t o t h e IJC i n Septem-. ber 1974. The outcome was an IJC recommendation t h a t an i n t e n s i v e environmental s tudy be undertaken as soon as p o s s i b l e t o develop data on environmental e f f e c t s o f r e g u l a t i o n i n bo th c o u n t r i e s . An accura te de te rm ina t i on o f t h e b e n e f i t s o f r e g u l a t i o n was a l s o recommended.

1.2 Charge t o Committee

The I n t e r n a t i o n a l Champlain-Richel ieu Board (ICRB) was e s t a b l i s h e d by t h e IJC on May 5, 1975 t o undertake these f u r t h e r s tud ies . The board was d i r e c t e d t o determine t h e f e a s i b i l i t y , b e n e f i t s and environmental impact o f r e g u l a t i n g water 1 eve1 s i n Lake Champlain and a p o r t i o n of t h e R i c h e l i e u R ive r , t o a l l e v i a t e damage from extreme wa te r , l eve l s . To conduct t he necessary i n v e s t i g a t i o n s , t h e Board formed t h r e e committees: t h e Phys ica l Aspects Committee which produced t h i s t e c h n i c a l r e p o r t ; t h e Environmental Impact Committee; and Net B e n e f i t s Committee whose a c t i v i t i e s a r e repo r ted separa te l y .

The Phys ica l Aspects Committee (PAC) was charged by t h e Board on J u l y 11, 1975 t o undertake t h e necessary s tud ies r e q u i r e d t o determine t h e eng ineer ing f e a s i b i l i t y , cos ts , and impact on water l e v e l s o f t h r e e s t r u c t u r a l a1 t e r n a t i v e s , i n c l u d i n g channel dredging, t o be cons t ruc ted i n t h e R i c h e l i e u R i v e r i n t h e v i c i n i t y o f S a i n t Jean, Que. The s t r u c t u - r a l a l t e r n a t i v e s i n v e s t i g a t e d were:

C A N A D A

N E W Y O R K

BOUNDARY OF DRAINAGE BASIN

DRAINAGE USIN

SCALE IN MILES GENERAL LOCATION P L A N

WATER SURFACE PROFILE FOR NATURAL CHANNEL

FLOW

DISTANCE FROM BORDER IN FEET X 1000

1. f i x e d c r e s t s t r u c t u r e a t S a i n t Jean; 2. gated s t r u c t u r e a t Sa in t Jean; and 3. t h e e x i s t i n g Fryers I s l a n d Dam.

Inc luded i n t h e scope o f PAC's work was t h e p repara t i on o f conceptual p lans, cos t es t imates , c o n s t r u c t i o n phasing, and r e g u l a t i o n procedures; an assessnient of t h e impact on l a k e and r i v e r l e v e l s ; t h e c a r r y i n g o u t o f h y d r o l o g i c and h y d r a u l i c i n v e s t i g a t i o n s , hydro- g raph ic surveys, phys i ca l and mathell lat ical model, and subsurface i n v e s t i g a t i o n s ; and t h e development o f channel dredging and dyk ing techniques. I n a d d i t i o n , PAC i n v e s t i g a t e d t h e u t i l i z a t i o n o f a f l o o d p r e d i c t i o n model, and the r i s i n g t r e n d i n l a k e l e v e l s . Th i s r e p o r t p resents t h e Committee's f i n d i n g s .

1.3 P rev iousWork

Previous r e p o r t s and surveys by agencies i n t h e Uni ted S ta tes and Canada concerning v a r i o u s aspects o f t h e Lake Champlain-Richel ieu bas in were s tud ied by PAC. When appro- p r i a t e , t h i s i n f o r m a t i o n was u t i l i z e d i n t h e s t u d i e s . P a r t i c u l a r a t t e n t i o n was g i ven t o t h e r e p o r t prepared by t h e Prov ince o f Quebec under da te o f November 1972, and t h e f i n a l r e p o r t and appendices prepared by t h e c u r r e n t Board 's predecessor, t he I n t e r n a t i o n a l Champlain-Richel i e u Engineer ing Board, dated September 1974. A 1 i s t o f a1 1 re fe rence m a t e r i a l i s a t tached.

1.4 Other Commi t t e e s

PAC main ta ined c l o s e l i a i s o n w i t h t h e Environmental Impact Committee (EIC) and t h e Net B e n e f i t s Committee (N6C) d u r i n g t h e course o f t h e s tud ies . PAC r e q u i r e d i n f o r m a t i o n f rom t h e two o t h e r committees i n o rde r t o fo rmula te r e g u l a t i o n schemes f o r l a k e l e v e l c o n t r o l which would s a t i s f y t h e p a r t i c u l a r concerns o f those two committees. Several meet ings were h e l d w i t h them du r ing t h e course o f t h e i n v e s t i g a t i o n s .

SECTION 2 GENERAL

2.1 Basin D e s c r i p t i o n

The Lake Champlain-Richel ieu R i v e r dra inage bas in occupies a t o t a l area o f approx- i m a t e l y 9,220 square m i l e s , of which 7,760 square m i l e s a r e i n t he Un i ted Sta tes ( i n t h e Sta tes o f New York and Vermont) and 1,460 square m i l e s i n t h e Prov ince o f Quebec ( F i g u r e 1 ) . From i t s head, i n t h e v i c i n i t y of Glen F a l l s , N . Y . , t he bas in extends a lmost due n o r t h f o r n e a r l y 200 m i l e s t o t he S t . Lawrence R ive r . The maximum bas in w i d t h i s about 112 mi les . I n t h e U n i t e d Sta tes , t he bas in topography i s rugged and mountainous w i t h peak e l e v a t i o n s up t o 5,344 f e e t i n t h e Adirondack Modntains of New York, and 4,393 f e e t i n t h e Green Mountains o f Vermont. I n t h e v i c i n i t y o f t h e i n t e r n a t i o n a l boundary and northward, t h e topography moderates t o f l a t p l a i n s .

The s u r f i c i a l geology o f t h e bas in dates f rom t h e P le i s tocene epoch when t h e e n t i r e area was occupied by t h i c k masses o f i c e which depressed t h e c r u s t o f t h e e a r t h w i t h t h e i r we ight . The southward advancing g l a c i e r s w i t h t h e i r lower p o r t i o n s charged w i t h asso r ted r o c k f ragments scoured and p o l i s h e d t h e hard rocks o f t h e Adirondacks and Green Mountains. On l ower p r o t e c t e d areas, however, t h e g l a c i e r s depos i t ed t h e i r l o a d o f d e b r i s as a heterogeneous m i x t u r e o f g l a c i a l t i l l . Lake Champlain i s t h e present day r e s u l t o f a huge l a k e formed i n t h e Champlain V a l l e y by t h e wast ing i c e b l o c k i n g t h e normal nor thward dra inage.

The Champlain lowland i s u n d e r l a i n by sedimentary rocks which a r e p r i m a r i l y sha le , l imestone, do lom i te and sandstone. I n t h e eas te rn p o r t i o n o f t h e lowland, t h e rocks have been metamorphised, f o l d e d and broken as a r e s u l t o f mountain b u i l d i n g fo rces . The Green Mountains and t h e Adirondacks a r e composed l a r g e l y o f Pre-Cambrian t o Devonian age metamorphics rang ing f rom p h y l l i t e s and s l a t e s t o l imestones, q u a r t z i t e s and gneisses.

Geo log ica l maps i n d i c a t e t h e presence o f two f a u l t s i n t h e S a i n t J e a n / I b e r v i l l e area which a r e o f i n t e r e s t t o t h i s s tudy . The Delson f a u l t formed i n an approx imate ly east-west d i r e c t i o n and t h e Tracy Brook fau l . t , i n a n o r t h - s o u t h d i r e c t i o n . O f t he two, t h e Delson f a u l t i s much l e s s impor tant , and i n d i c a t i o n s a r e t h a t i t may n o t ex tend as f a r as t h e R i c h e l i e u R ive r . The Tracy Brook f a u l t , o r i g i n a t i n g i n t h e Un i ted Sta tes and c r o s s i n g t h e R i c h e l i e u R i v e r a t S a i n t Jean, i s much more impor tan t . It i s g e n e r a l l y -regarded as s t a b i l i z e d ; however, i t m igh t be r e a c t i v a t e d by an earthquake.

The S a i n t Jean area i s l o c a t e d i n an i n t e r m e d i a t e p r o b a b i l i t y earthquake zone and n o t i n a zone c l a s s i f i e d as dangerous where t h e f a u l t cou ld be r e a c t i v a t e d . Any r i v e r s t r u c t u r e , however, should be designed a c c o r d i n g t o standards a p p l i c a b l e t o t h e zone ( i n terms o f h o r i z o n t a l s t r a i n and v e r t i c a l a c c e l e r a t i o n ) .

Lake Champlain, t h e l a r g e s t body o f water i n t h e bas in , occupies a pass i n t h e Appalachian Highlands between t h e Adirondack and Green Mountains. For a d i s t a n c e o f about 100 m i l e s , f rom Wh i teha l l , N.Y. nor thward t o i t s o u t l e t a t Rouses Po in t , t h e l a k e forms t h e boundary between t h e Sta tes o f New York and Vermont, w h i l e M iss i squo i Bay t o t h e eas t o f t h e o u t l e t extends an a d d i t i o n a l s i x t o seven m i l e s i n t o Quebec. With a maximum w i d t h of 12 m i l e s , t h e l a k e has a water su r face area o f 436 square m i l e s , o f which 419 l i e i n t h e U n i t e d S ta tes . There a r e a number of l l e r l akes i n t h e bas in most o f which a r e l o c a t e d on t h e west s i d e m a - w York > t a r e . I ne l a r g e r 0-7 eRese a r e Lake George, Lake P l a c i d and t h e t h r e e Saranac Lakes. Some o f t he l a r g e r streams e n t e r i n g Lake Champlain a r e t h e Chazy, Saranac and Ausable R ive rs f rom the west, and O t t e r Creek, t h e Winooski, L a m o i l l e and M i s s i s q u o i R i ve rs f rom t h e east .

The R i c h e l i e u R i v e r w h i c h d r a i n s Lake Charnplain i s l o c a t e d e n t i r e l y i n Canada. It pursues a c o u r s e f r o m t h e Lake o u t l e t a t Rouses P o i n t , N.Y., a l m o s t due n o r t h f o r 8 0 m i l e s t o i t s j u n c t i o n w i t h t h e S t . Lawrence a t S o r e l , Que. I n i t s course , t h e r i v e r d r a i n s a n a r r o w s t r i p o f t e r r a i n w i t h a maxirnu~n w i d t h o f a b o u t 16 m i l e s and an a r e a o f l e s s t h a n 1,000 square m i l e s .

I n t h e f i r s t 23 m i l e s , between Rouses P o i n t , N.Y. and S a i n t Jean, Que., t h e r i v e r g r a d i e n t s l o p e s v e r y g e n t l y , a p p r o x i m a t e l y one f o o t a t average d i s c h a r g e c o n d i t i o n s . I n t h e n e x t 1 2 - m i l e r e a c h f r o m S a i n t Jean t o Chambly B a s i n , t h e r i v e r d r o p s a t o t a l o f a b o u t 70 f e e t t h r o u g h a s e r i e s o f r a p i d s . The Chambly Canal passes a l o n g t h e w e s t s i d e o f t h e r i v e r i n t h i s r e a c h t o f a c i l i t a t e n a v i g k t i o n . F r y e r s I s l a n d Dam i s l o c a t e d a b o u t s i x m i l e s downstream f r o m S a i n t Jean ( F i g u r e 2 ) .

Water l e v e l s i n t h e channel be low Chambly B a s i n a r e c o n t r o l l e d by a dam n e a r S t . Ours, Que. , w h i c h i s 31 m i l e s downstream f r o m Chambly B a s i n . From S t . Ours dam, t h e R i c h e l i e u R i v e r f l o w s a n a d d i t i b n a l 14 m i l e s t o j o i n t h e S t . Lawrence a t S o r e l , w h i c h has a mean e l e v a t i o n o f a b o u t 16.5 f e e t , G e o d e t i c Survey o f Canada (GSC) datum1

The R i c h e l i e u R i v e r , f r o m Rouses P o i n t , N.Y. t o be low S a i n t Jean, p r o v i d e s Lake C h a m p l a i n ' s o u t l e t and c o n t r o l . F o r t h e f i r s t 23 m i l e s , t h e r i v e r i s w i d e and t h e i m p e d i - ment t o f l o w i s n o t g r e a t . A t S a i n t Jean, t h e r i v e r becomes n a r r o w e r and t h e b o t t o m r i s e s t o t h e head o f t h e r a p i d s . The r a p i d s e x t e n d a d i s t a n c e o f a b o u t two m i l e s e x h i b i t i n g v e l o c i t i e s and c h a r a c t e r i s t i c s a s s o c i a t e d w i t h r i v e r c o n t r o l s e c t i o n s . I n t h i s r e a c h t h e s l o p e o f t h e r i v e r i s q u i t e s t e e p . Below t h e r a p i d s , t h e r i v e r i n c r e a s e s i n c r o s s - s e c t i o n , t h e v e l o c i t y becomes more t r a n q u i l and t h e s l o p e o f t h e r i v e r becomes f l a t t e r u n t i l F r y e r s I s l a n d i s reached .

The S a i n t Jean s h o a l a c t s l i k e a t r u e h y d r a u 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 o u t f l o w s o f Lake Champlain. P h y s i c a l model t e s t s c i v e a l l i n d i c a t i o n s t h a t i t i s t h e c o n t r o l . A l s o , m a t h e m a t i c a l a n a l y s e s p o i n t t h i s same way. Water l e v e l s u p s t r e a m o f S a i n t Jean a r e t h e r e f o r e i n f l u e n c e d a l m o s t e n t i r e l y by t h e shoa l and have a r e l a t i v e l y f l a t s l o p e . The u p s t r e a m w a t e r s l o p e t h e r e f o r e rema ins a f u n c t i o n o f t h e s t reambed roughness s i n c e t h e r i v e r s p r i m a r y l e v e l and r a t e o f d i s c h a r g e i s l i m i t e d t o i t s c a p a c i t y a t t h e s h o a l .

2 .2 Hydro1 ogy

2.2.1 C l i m a t e

The C h a m p l a i n - R i c h e l i e u b a s i n i s c h a r a c t e r i z e d by r e l a t i v e l y l o n g w i n t e r s and s h o r t m o d e r a t e l y warm summers. The upper reaches o f t h e b a s i n i n t h e Green M o u n t a i n s o f Vermont and t h e A d i r o n d a c k s o f New York have g e n e r a l l y l o w e r t e m p e r a t u r e s and more p r e c i p i t a t i o n t h a n t h e c e n t r a l and l o w e r p o r t i o n s o f t h e b a s i n where t e m p e r a t u r e s a r e modera ted by Lake Champla in. Mean annua l t e m p e r a t u r e o f t h e w h o l e b a s i n i s 70C (45OF).

Average annua l p r e c i p i t a t i o n v a r i e s f r o m 28 i n c h e s a t t h e n o r t h w e s t e r n s h o r e o f Lake Champla in t o 60 i n c h e s a l o n g t h e r i d g e o f t h e Green M o u n t a i n s and A d i r o n d a c k M o u n t a i n s . The v a r i a t i o n s r e f l e c t t h e i n f l u e n c e o f topography , t h e l a k e and t h e p r e v a i l i n g w e s t e r l y w inds . P r e c i p i t a t i o n i s f a i r l y u n i f o r m t h r o u g h o u t t h e y e a r w i t h s l i g h t l y more t h a n h a l f f a l l i n g d u r i n g t h e summer season. Thunders to rms a r e common, r e s u l t i n g i n t h e summer r a i n f a l l o c c u r r i n g i n s h o r t p e r i o d s o f t i m e . S n o w f a l l i s v a r i a b l e , r e a c h i n g 100 i n c h e s o r more i n t h e h i g h e r e l e v a t i o n s , b u t d e c l i n i n g t o 65 i n c h e s ' i n t h e l o w e r b a s i n .

2 .2 .2 Runof f

R u n o f f i n t h e C h a m p l a i n - R i c h e l i e u b a s i n i s measured a t 20 stre.am g a u g i n g s t a t i o n s i n Vermont , e i g h t i n New York S t a t e , and one i n t h e P r o v i n c e o f Quebec. The a v e r a g e annua l

1 USGS e l e v a t i o n s = GSC e l e v a t i o n s +0.37 f e e t

I runof f i n t h e bas in i s es t ima ted a t 22 inches, r e p r e s e n t i n g s l i g h t l y l e s s than 63 per cen t of t he p r e c i p i t a t i o n . The average annual evapo ra t i on f rom t h e su r face o f Lake Champfain i s approx imate ly 24 inches, most o f which occurs d u r i n q t h e summer and f a l l months.

1 I hcd a nlean d l u e o f 43,700 c f s .

recorded minimum occur red on o f & m e long- term

I o f t h e bas in c o n t r i b u t e s abou: 4,000 c f s of t h e t o t a l , w i t h Vermont about 6,000 c f s and Quebec about 1,000 c f s .

The r e s u l t s of frequency analyses us ing t h e p e r i o d o f r e c o r d f rom 1938 t o 1976 have been shown on F igu res 4 and 5.

2 .2 .3 Lake Leve ls

The l e v e l s of Lake Champlain a r e measured a t t h r e e l o c a t i o n s : Rouses P o i n t , N.Y. s i n c e 1871; B u r l i n g t o n , V t . s i nce 1907; and a t P h i l i p s b u r g , Que. s i n c e 1964. Leve l s a f f e c t i n g t h i s s tudy have a l s o been measured on the R i c h e l i e u R ive r and a t severa l l o c a - t i o n s f o r v a r y i n g pe r i ods o f t i m e d a t i n g back t o t he 1920 's .

maximum recorded water su r face e l e v a t i o n o f Lake Champlain, 101.80 f e e t U n i t e d S ta tes Geo log ica l Survey (USGS) datum was recorded a t Rouses Po in t , N . Y . , on March 30, 1903. T e minimum recorded l e v e l , 92.4 USGS, was recorded a t t h e same l o c a t i o n

ovembw 13, 1 9 0 a S i m i l a r f requency analyses of Lake l e v e l s u t i l i z i n g da ta f o r t h e p e r i o d 1938 t o 1976 a r e presented on F i g u r e 6 and 7.

The f o l l o w i n g l i s t g i v e s t h e f i v e h i g h e s t and lowest mean d a i l y stages a t Rouses P o i n t f o r t h e p e r i o d 1938-1976:

H I G H - - - -

DATE Level USGS

A p r i l 4, 1976 101.51 May 9, 1972 101.44 May 12, 1971 101.21 A p r i l 30, 1939 101.07 June 5, 1947 101.02

L O W - - -

October 16, 1941 92.90 November 7, 1953 93.12 November 4, 1949 93.24 November 18, 1954 93.35 November 12, 1952 93.37

The normal behav iour o f t h e l a k e i s f o r i t t o s t a r t f rom a f a l l low o f about 94.3 f e e t USGS i n October, r i s e s l o w l y t o 95.3 f e e t USGS about t h e f i r s t o f March, r i s e r a p i d l y t o about 98.7 f e e t USGS by t h e f i r s t o f May, and then f a l l g r a d u a l l y th roughout t h e s p r i n g and summer t o 94.3 f e e t USGS aga in by October. The mean water l e v e l o f Lake Champlain i s ' about 95.5 f e e t USGS. H i s t o r i c a l l a k e l e v e l da ta a r e p rov ided i n F igu re 8. i Flood ing a long t h e lakeshore 4s u s u a l l y a s p r i n g occur rence and i s caused by a

combinat ion o f s n o m e l t and s p r i n g r a i n f o l l o w i n g an extended p e r i o d o f above normal p r e c j p i t a t i o n . The upper R i c h e l i e u R i v e r f rom t h e l a k e o u t l e t down t o S a i n t Jean has c h a r a c t e r i s t i c s s i m i l a r t o t h e l a k e and f l o o d i r ~ g occurs s imul taneous ly w i t h f l o o d stages i n t h e l a k e .

1.006 t .OS 1 -25 2 .O 6 -0 10. 20. SO* 100- 200- 500.

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(IWB-6s) RECURRENCE INTERVAL IN YEARS

PROBABILITY

1.25 2.0 5.0 1C). 2C.

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v (IWB-68) RECURRENCE INTERVAL IN YEARS 10001 1001 101 115 2 33 5 6.94 10 20 50 100 200 500 1000 2000 5000 10,000

1 . I I 1 I I I I I I I I

PROBABILITY

8 I. ' 1 1 1 1 l 1 1 1 1 I I I ~ t j $ t i + i ~ # t t t + ~ i , I I I ~ I T : l l ~ l , T ~ ~1 I I I 1 I 1 I I I I I I i ~ t i I I ; 1. (YEARS)

Y L . u I I ' I 1 I ' l l , / , I 1 1 1 I l l / , I 1 1 1 1 1 1 1 1 1 1 1 I I I I I , I , ' I I I I 0 0 1 0 1 1 5 10 20 3 0 4 0 5 0 60 70 80 90 95 98 99 99 8 99 9 99 99

MEAN DAILY ELEVATION OF LAKE CHAMPLAIN AT ROUSES POINT, NEW YORK, OCTOBER 1938 TO SEPTEMBER 1977

OCT NOV D EC JAN FEB MAR APR MAY JUNE - JULY AUG SEPT

NOTE: ELEVATIONS TO U.S.G.S. DATUM

2 . 3 H y d r a u l i c A n a l y s e s

The e n t i r e 2 9 - n l i l e l e n g t h o f t h e upper R i c h e l i e u R i v e r fro111 F r y e r s I s l a n d Dam t o t h e I n t e r n a t i o n a l B o r d e r has been r e p r e s e r i t e d mathema t i c a l l y u t i 1 i z i n g numerous c r o s s - s e c t i o n s I# o f t h e r i v e r taker) t ~ t s e l e c t e d l o c a t i o n s : , The l e ! ~ i q t t ~ o f t h e r i v e r has been d i v i d e d i n t o two d i s t . i r i c t r ( ! ~ ~ ~ t i ( ! s , OII[: fro111 F r y c r s I ~ l i l n d Dam up I.o t t rc? Gouir l U r i d g c and i n c l u d i n g S a i n t Jcarl I < ~ t l ) i d s , and t h e other e x t c t . ~ d i r ~ ! l 23 111i1es f a r t h e r u l )s t reas l t o t h e b o r d e r . By means o f b a c k w a t c r ' co lnpu ta t io r l s s t a r t i n g fro111 a stage-discharge r e l a t i o n s h i p a t a known l o c a t i o n , w a t e r s u r f a c e p r o f i l e s can be s i ~ l i u l a t e d f o r any c o n d i t i o n o f f l o w o r channe l c o n f i g u r a t i o n .

I

These backwate r c o m p u t a t i o n s were used i n t h e s t u d i e s t o o b t a i n R i c h e l i e u R i v e r w a t e r s u r f a c e p r o f i l e s and c o r r e s p o n d i n g l a k e l e v e l s a t v a r i o u s d i s c h a r g e s f o r t h e n a t u r a l s t a t e , a s w e l l as r e g u l a t e d c o n d i t i o n s . F o r r e g u l a t i o n a n a l y s e s , backwate r c o m p u t a t i o n s were r e q u i r e d t o e s t a b l i s h s t a g e - d i s c h a r g e r e l a t i o n s h i p s a t t h e l a k e o u t l e t f o r d i f f e r e n t

I l e v e l s o f c o n t r o l s t r u c t u r e o p e r a t i o n , u n d e r d redged channel c o n d i t i o n s .

A l l c o m p u t a t i o n s were c a r r i e d o u t by compute r . The p rogram used w HEC-2, h i c h i s a w a t e r s u r f a c e p r o f i l e program deve loped by t h e H y d r o l o g i c E n g i n e e r i n g Ce Army Corps o f Eng ineers , Dav is , C a l i f . I t employs t h e s t a n d a r d s t e p method i n w h i c h t o t a l e n e r g y i s a p p l i e d a t r i v e r c r o s s - s e c t i o n s . M a n n i n g ' s f o r m u l a i s used t o compute t h e f r i c t i o n head l o s s between s e c t i o n s . O t h e r h y d r a u l i c l o s s e s a r e a l s o c o n s i d e r e d i n t h e c o m p u t a t i o n s , such as eddy, channe l t r a n s i t i o n , b r i d g e and p i e r e f f e c t s . There i s c o n s i d e r a b l e f l e x i b i l i t y i n t h e program; f o r example, c r o s s - s e c t i o n a l d a t a can be i n t e r - p o l a t e d : f o r g r e a t e r a c c u r a c y i n comput ing t h e h y d r a u l i c p r o f i l e . C r i t i c a l d e p t h i s a l s o d e t e r m i n e d a t each s e c t i o n .

Model c a l i b r a t i o n was a c h i e v e d u s i n g w a t e r s u r f a c e p r o f i l e d a t a c o l l e c t e d d u r i n g 1975 and 1976 a t 16 l o c a t i o n s on t h e r i v e r between F r y e r s I s l a n d Dam and Rouses P o i n t f o r a c o m p l e t e r a n g e o f f l o w s f r o m l o w t o h i g h . These d a t a were used t o e v a l u a t e M a n n i n g ' s ' n ' v a l u e s o v e r t h e c o m p l e t e d i s c h a r g e range . The c r o s s - s e c t i o n a l d a t a used i n t h e model f o r t h i s s t u d y i n c l u d e d t h o s e o b t a i n e d f rom t h e m o s t r e c e n t sound ings . T h i s i n c l u d e d t h e 1937 s u r v e y f r o m F r y e r s I s l a n d Dam t o Highway 35 b r i d g e , 1977 sound ings t h r o u g h t h e shoa l a r e a , and 1973 d a t a f r o m t h e head o f t h e s h o a l t o Lake Champla in.

2 .4 R e g u l a t i o n Ana lyses Methodo logy

The p u r p o s e o f t h e r e g u l a t i o n a n a l y s e s p r e s e n t e d i n t h i s r e p o r t i s t o f o r m u l a t e and t h e n e v a l u a t e p o s s i b l e schemes f o r t h e c o n t r o l o f l e v e l s and o u t f l o w s o f Lake Champla in. The a im o f a r e g u l a t i o n scheme i s t o b e n e f i t as many i n t e r e s t s a s p o s s i b l e w h i l e a t t h e same t i m e m i n i m i z i n g o r enhanc ing p o t e n t i a l damage t o o t h e r i n t e r e s t s . A p a r t i c u l a r scheme s h o u l d c o n s i s t o f o b j e c t i v e s t o be s a t i s f i e d , a d e c i s i o n p r o c e s s o r r u l e s o f o p e r a t i o n t o meet g i v e n o b j e c t i v e s , and a f o r e c a s t o f n e t b a s i n s u p p l i e s ( i n f l o w s ) .

The p r i m a r y o b j e c t i v e s o f t h i s p roposed developrl ient a r e t o r e d u c e h i g h l a k e s t a g e s w h i c h cause f l o o d i n g and t o m a i n t a i n c o n d i t i o n s t h a t a r e n o t u n d u l y h a r m f u l t o p l a n t and an ima l l i f e a l o n g t h e l a k e and r i v e r . The E n v i r o n m e n t a l I m p a c t Commit tee has i d e n t i f i e d t h e a f f e c t e d e n v i r o n m e n t a l r e s o u r c e s and examined t h e e f f e c t o f v a r y i n g l a k e l e v e l s . T h a t commi t tee has p r o v i d e d c e r t a i n c r i t e r i a on l a k e l e v e l s t o m i n i m i z e i m p a c t on v e g e t a t i o n , f i s h spawning h a b i t a t , w a t e r f o w l n e s t i n g , and f u r b e a r i n g a n i m a l s . A t t h e same t i m e , t h e N e t B e n e f i t s Comnii t tee has p r o v i d e d i n f o r m a t i o n o n l e v e l s w h i c h w o u l d n o t u n d u l y harm o t h e r i n t e r e s t s . A l l o f t h e s e d a t a have been used t o e s t a b l i s h o b j e c t i v e s o r c o n s t r a i n s i n t h e r e g u l a t i o n a n a l y s e s .

It i s common p r a c t i c e t o assess b e n e f i t s and i m p a c t s o n p roposed w a t e r r e s o u r c e . .

d a t a and o u t f l o w s a r e a v a i l a b l . .

c o r r e s p o n d i n g change i n 1 ake s t o r a g e . F o r any r e g u l a t i o n scheme, t h e s e i n f l o w s were- r o u t e d , s u b j e c t t o c o n s t r a i n t s , t h r o u g h t h e r e g u l a t o r y works under c o n s i d e r a t i o n . Such works wou ld l o w e r t h e e n t i r e n a t u r a l s t a g e - d i s c h a r g e c u r v e due t o i n c r e a s e d channe l

c a r r y i n g c a p a c i t y as a r e s u l t o f d redg ing and, i n t l ~ c case of a ga ted s t r u c t u r e , e r~ab l c r e g u l a t i o n o f o u t f l o w s by o p e r a t i o n o f t h e ga tes . 111 o rde r t o assess \.t:gulc\t..ion c ' f f r c t s on f u t u r e c o n d i t i o n s as c l o s e l y as p o s s i h l c , Lake Cha l~~p la i l l h i s t o r i c a l l(?vc:ls were. d l 1 referenced t o present c o n d i t i o n s . Th i s was acco~npl i shed by r o u t i n g t h e c o ~ ~ ~ p u t e d h i s t o r i c d l i n f l o w s th rough t h e l a k e w i t h 1976 s tage-d ischarge c o n d i t i o n s a t t h e l a k e o u t l e t :

A1 1 t h e r e g u l a t i o n analyses were c a r r i e d o u t by computer, us ing e s t a b l i shed programs and r o u t i n e s a v a i l a b l e ill Environment Canada. D a i l y hydrographs were produced showing n a t u r a l and r e g u l a t e d l e v e l s on Lake Champlain f o r t h e p e r i o d . The computer program a l s o c a l c u l a t e d average annual damages based on t h e f requency o f occurrence o f t h e n a t u r a l events. From these analyses, any scheme can be compared t o t h e n a t u r a l s t a t e as a base case. Thus b e n e f i t s can be computed as w e l l as environmental impacts assessed. I t i s t h e r e f o r e p o s s i b l e t o compare a1 1 schemes as t o economic b e n e f i t s and environmental impact .

2 .5 F i e l d Stud ies

A d d i t i o n a l f i e l d work was undertaken as p a r t of t he s tudy program t o supplement da ta t h a t were a v a i l a b l e f rom p rev ious i n v e s t i g a t i o n s and s tud ies , and t o p r o v i d e i n f o r m a t i o n f o r des ign and c o s t es t imates o f t h e f i x e d c r e s t s t r u c t u r e . Some f i e l d work was a l s o r e l a t e d t o i n v e s t i g a t i o n o f t h e changing d ischarge r e l a t i o n s h i p o f Lake Champlain which i s d iscussed i n Sec t i on 7 o f t h i s r e p o r t .

The f i e l d work i nc luded t h e g a t h e r i n g o f h y d r o l o g i c data f o r c a l i b r a t i o n o f t h e ma thena t i ca l backwater model and geo techn i ca l i n f o r m a t i o n a t t h e s i t e o f t h e f i x e d c r e s t s t r u c t u r e . The h y d r o l o g i c program extended over a p e r i o d o f two years and cons i s ted o f o b t a i n i n g water s u r f a c e l e v e l s a t 16 l o c a t i o n s between F rye rs I s l a n d Dam and Rouses Po in t , N.Y. T h i r t e e n s t a f f gauges and t h r e e r e c o r d i n g gauges were i n s t a l l e d d u r i n g t h e open water season t o o b t a i n these data . The work was c a r r i e d o u t w i t h t h e ass i s tance o f t h e Montreal o f f i c e o f t h e Water Resources Branch of Environment Canada. The o t h e r aspect o f t h e h y d r o l o g i c program, inc luded resounding o f t h e S a i n t Jean shoal a rea and t h i s was c a r r i e d o u t i n A p r i l 1977 w i t h t h e coope ra t i on o f t he App l i ed Hydrology D i v i s i o n o f t h e Water Resources Branch, Environment Canada. T h i r t y s e c t i o n s o f t h e r i v e r were sounded under t h e program and t h e i n f o r m a t i o n was used i n t h e mathemat ical model as w e l l as f o r t h e c a l c u l a - t i o n o f d redg ing q u a n t i t i e s .

A geo techn i ca l survey undertaken under c o n t r a c t was c a r r i e d o u t a t t h e s i t e o f t h e f i x e d c r e s t s t r u c t u r e i n September 1976. The work i n v o l v e d d r i l l i n g s i x ho les on t h e a x i s o f t h e proposed f i x e d c r e s t s t r u c t u r e , t oge the r w i t h overburden sampl ing and l a b o r a t o r y a n a l y s i s o f t h e samples. The l o c a t i o n s o f t h e ho les a r e shown i n F i g u r e 9 t o g e t h e r w i t h o t h e r d r i l l ho les p r e v f o u s l y d r i l l e d i n 1972 and 1973.

2 .6 Phys i ca l Model S tud ies

The c o n s t r u c t i o n o f h y d r a u l i c s t r u c t u r e s i s o f t e n preceded by s i m u l a t i o n s t u d i e s under c o n t r o l l e d c o n d i t i o n s . The purpose o f such s t u d i e s i s t o de termine those cha rac te r - i s t i c s o f f l o w and s t r u c t u r e performance which a r e n o t r e a d i l y a s c e r t a i n e d by o t h e r analyses. Models have become a v a l u a b l e t o o l i n o b t a i n i n g data f o r r e l i a b l e and economic des ign o f r i v e r s t r u c t u r e s . They n o t o n l y a i d i n de te rm in ing t h e f a c t o r s which shou ld be cons idered i n des ign ing r i v e r s t r u c t u r e s , b u t g i v e a prev iew o f t he behav iour o f t h e p r o t o - t y p e under v a r i o u s c o n d i t i o n s as w e l l .

Model 1 i n g s t u d i e s a r e accompl i shed by t h e development o f smal l s c a l e p h y s i c a l dupl i c a t e s o f t h e proposed c o n s t r u c t i o n works. These dupl i c a t e s a r e g e o m e t r i c a l l y s i m i l a r t o t h e p r o t o t y p e be ing s tud ied . They a r e a l s o arranged so t h a t t h e f l o w o f water i s dynamica l l y s i m i l a r t o t h a t o f t h e p ro to t ype . The methods employ s tandard procedures f o r de te rm in ing by c a l i b r a t i o n t h e c h a r a c t e r i s t i c s o f t h e model th rough t h e a p p l i c a t i o n o f equat ions d e s c r i b i n g t h e more impor tan t parameters o f f l o w . These a r e g e n e r a l l y t h e i n e r t i a and g r a v i t y f o r c e i n f l u e n c e s m o d i f i e d somewhat by t h e e f f e c t o f f r i c t i o n .

A f t e r t h e model has been c a l i b r a t e d t o rep resen t t h e p ro to t ype , t e s t s a r e then r u n t o p r o v i d e da ta on how t h e p r o t o t y p e w i l l f u n c t i o n under des ign c o n d i t i o n s . These t e s t s cover t h e f u l l range o f expected c o n d i t i o n s i n o r d e r t h a t t h e behav iour o f t h e proposed c o n s t r u c t i o n works i s understood. M o d i f i c a t i o n s t o t h e des ign o f t h e p r o t o t y p e a r e made i n t h e model where t e s t i n g i n d i c a t e s t h a t performance can be improved.

SCALE

-1 0 4 0 0 8 0 0 1200 1600 FT.

EATED STRUCTURE SITE

IBERVILLE , ,

i INTERNATIONAL CHAM PLAIN - RICHELIEU BOARD

RICHELIEU RIVER REGULATORY WORKS

LOCAT ION OF BORE-HOLES

PMYSICAL ASPECTS . COMLIITTEL ne. o

Stud ies were conducted a t t h e LaSa l l e Hyd rau l i c Labora tory i n LdSa l l e , Que., and l a t e r a t t h e Canada Centre f o r I t i l sn t l Waters i n Ih r r l i ng ton , Ont. The i n v e s t i g a t i o n s were colaple~nentary, t he c ! f f o r t progress-in!] ill t.o lriore d e t a i 1 ed s t u d i e s as the work cont inued. Model 1 -in!] schctlul es were arranged so t h , ~ t o t h e r r lccessary a c t i v i t i e s srrch as backwater and r e g u l a t i o n ana'lyses. s t r u c t u r a l drawings, e t c . , were pe rn l i t t ed t o go fo rward w i t h t h e da ta developed.

The model s t u d i e s were broken i n t o t h e f o l l o w i n g c a t e g o r i e s :

A. A t LaSa l l e H y d r a u l i c Labo ra to ry .

i. o v e r a l l i n f l u e n c e of t h e proposed f i x e d c r e s t s t r u c t u r e ; ii. o v e r a l l i n f l uence of t h e proposed gated s t r u c t u r e ; iii. c o n s t r u c t i o n phasing of t h e proposed f i x e d c r e s t s t r u c t u r e ;

i v . c o n s t r u c t i o n phasing o f t h e proposed gated s t r u c t u r e ; v. e f f e c t o f Chambly Canal widening.

B. A t t h e Canada Centre f o r I n l a n d Waters.

i. performance o f t h e proposed f i x e d c r e s t s t r u c t u r e ; ii. performance o f t h e proposed gated s t r u c t u r e ; iii. eros ion s t u d i e s of t h e proposed f i x e d c r e s t s t r u c t u r e ;

i v . e r o s i o n s t u d i e s o f t h e proposed gated s t r u c t u r e .

A t t h e LaSa l l e Labora tory , t he model was cons t ruc ted t o rep resen t t h e e n t i r e l e n g t h of t h e proposed dredged channel and had a f i x e d bed. H o r i z o n t a l l y , t h e s c a l e o f t h e model was one f o o t i n t h e l a b o r a t o r y t o 111 f e e t i n t h e p ro to t ype . V e r t i c a l l y , one f o o t i n t h e model represented 45 f e e t i n t h e p ro to t ype . O v e r a l l , t he model was about 100 f e e t l o n g and about 200 f e e t a t i t s w ides t . The channel su r face was made o f roughened cement mor ta r , t h e ga ted s t r u c t u r e o f p l e x i g l a s s , and t h e va r i ous we i r s t e s t e d were o f smooth o r roughened cement mor ta r . Four p iezometer connect ions ( w i t h p o i n t gauges) were used t o measure water l e v e l s . . Sequent ia l photos o f su r face c u r r e n t s were u t i l i z e d t o measure f l o w v e l o c i t i e s . A f t e r t h e f i r s t s e r i e s o f t e s t s were completed, a p o r t i o n o f t he model was reshaped t o rep resen t t h e e x i s t i n q channel bot tom f o r t h e t e s t s o n ~ c . o , ~ s ~ t . c u c . t . i a n s . t ~ g ~ and cana l

bot tom con tou rs were based on data f rom 1973 t h e ones ob ta ined i n 1937 and 1977 by up t o two f e e t .

da ta may t h e r e f o r e r e q u i r e v e r i f i c a t i .

A t t h e Canada Cent re f o r I n l a n d Waters, bo th t h e w e i r and gated s t r u c t u r e were I mode l led w i t h i n a one-metre f lume hav ing an a d j u s t a b l e s lope, aluminum bot tom and g lass

s ides . P e r i p h e r a l appara tus i nc luded a v idea camera and sound r e c o r d i n g equipment. The s t r u c t u r e s were represented by s e c t i o n a l l eng ths , t h e w e i r cons t ruc ted o f plywood, and t h e sec to r g a t e o f aluminum mounted on a wooden frame. Water l e v e l s were measured by gauges mounted bo th upstream and downstream o f t h e model s t r u c t u r e s . V e l o c i t i e s were measured by c u r r e n t meters i n s e r t e d i n t o t h e water . The model o f t h e w e i r was cons t ruc ted t o an u n d i s t o r t e d s c a l e o f one f o o t i n t h e model t o 9.83 f e e t i n t h e p ro to t ype . Weir performance t e s t s were conducted us ing t h e f u l l w i d t h o f t h e f lume. For t h e e ros ion t e s t s , f l o w was passed th rough a 2.5 f o o t wide plywood box mounted over t h e f lume bottom t o g a i n c lea rance f o r r i v e r wash sand, t he m a t e r i a l used t o rep resen t r i p r a p . S tud ies o f t h e ga ted s t r u c t u r e bo th f o r performance and e ros ion t e s t i n g were conducted w i t h i n a s i m i l a r 2.5 f o o t wide box, t h e model be ing cons t ruc ted t o an u n d i s t o r t e d s c a l e o f one f o o t i n t h e model t o 12 f e e t i n t h e p ro to t ype . Repor ts have been prepared f o r these model s t u d i e s and a r e i n c l u d e d w i t h t h e suppo r t i ng da ta .

2.7 Cost C r i t e r i a

A l l e'stim'ates o f c o s t were computed on t h e bas i s o f c o n s t r u c t i o n q u a n t i t i e s d e r i v e d f rom t h e p r e l i m i n a r y des ign and l a y o u t drawings. U n i t p r i c e s were ob ta ined f rom analyses o f r e c e n t c o n s t r u c t i o n p r o j e c t s i n t h e Mont rea l area and f rom i n f o r m a t i o n s u p p l i e d by t h e Cons t ruc t i on D i v i s i o n o f t h e Quebec Department o f Na tu ra l Resources. A l l c o s t s a r e a t 1977 rice l e v e l s and i t i s assumed t h a t a l l work would be c a r r i e d o u t on a c o n t r a c t bas i s .

1 Cost" used i n t h i s r e p o r t i nc ludes a l l expend i tu res r e q u i r e d t o and b r i n g them i n t o b e n e f i c i a l use. I n a d d i t i o n t o t h e d i r e c t c o s t

incurred in building s t ruc tu re s and in providing and erect ing equipment, the estimates a1 low fo r land and property acquis i t ion , engineering and supervision, preliminary invest i - gat ions, e t c . The t o t a l construction cost and i n t e r e s t charges during construction were added based on the investment spread uniformly over the t o t a l construction period.

Annual cost includes a l l annual costs occurring a f t e r ac t iva t ion of each project and ,

includes the f o l l owing fac tors :

a ) i n t e r e s t and amortization of cap i ta l cos t ; b) a1 lowance of interim replacei~ient of equi plnent and f ac i l i t i e s ; c ) operation and maintenance expense; d) administration and general expense.

A 50-year period was considered for the overall project l i f e in calculat ing i n t e r e s t and amortization as well as allowance fo r interim replacement. An i n t e r e s t r a t e of 7; per cent was chosen fo r economic evaluation purposes. Interim replacement cos t s were estimated as a percentage of the d i r e c t cos t of the items varyiiig from 0.15 per cent t o 0.40 per cen t . Operation and maintenance was estimated s imi la r ly as a percentage of d i r e c t cost of i terns ranging from 0.25 t o 2.0 per cent. Administration and general expense was taken as 30 per cent of the cos t of operation and maintenance.

2.8 Regulation Cr i t e r i a

2.8.1 Environmental Impact Committee

Lake level regulation t a rge t s provided as a r e su l t of Environmental Impact Committee s tud ies a re quoted as follows:

1 . When lake levels reach 98.5 f e e t USGS, maintain leve ls a t or above 98.5 f ee t USGS fo r a minimum of 40 days. His tor ica l ly t h i s has occurred 18 tinies in the 40 years between 1938-1977; 15 times between April 1 and April 21.

4. By mid June lake leve ls should be a t o r below 96.3 f e occurred 25 times in the 40 years between 1938-1977.

5. By mid Ju ly , the lake level should be no lower than 95.5 f ee t USGS. His tor ica l ly ntf$$&. t h i s has occurred 20 times 0 ~ e v e k should f a l l lube*) gradually t o not lower than 94.0 f e e t USGS by November 1 . The November 1 lake levels have been 94.0 f e e t USGS o r higher 23 times in the 40 years , between 1938-1977. \ -

6. During November through February, lake leve ls should follow the natural trend of r i s i ng but should be i t e d over the four month t o a maximum of 1.5 f e e t above the November 1 level . f o r a .5 foot r i s e 2 The r i s e between November 1 and February 28 has been o r l e s s during 26 of t he 40 years between 1938-1977.

7. Consistent with environmental regulation c r i t e r i a 1 ) through 6 ) and within the context of h i s t o r i ca l hydraulic data on lake leve ls and r i ve r discharges the ecosystem below Saint Jean rapids should be maintained.

2.8.2 Net Benefits Commi t t e e / Target l eve ls provided by the Net Benefits Committee as a r e su l t of t he i r ' s t ud i e s ,

which maximize economic benefi ts , a r e quoted as follows: I 1. Reduce flood s tages t o elevat ion 95.0 f e e t USGS during the period from October 15 t o

May 1.

2.8.3 Management C r i t e r i a

I n a d d i t i o n t h e Board d i r e c t e d PAC t o e v a l u a t e E n v i r o n m e n t a l I m p a c t Committee c r i t e r i a i tem 1 a t a1 t e r n a t e e l e v a t i o n s o f 98.0 and 97.5. A l s o a minimum d i s c h a r g e o f 3,000 c f s was s p e c i f i e d (minimum d i s c h a r g e w i t h a f r e q u e n c y o f 1 i n 2 y e a r s ) f o r schemes s a t i s f y i n g t h e above c r i t e r i a .

SECTION 3 CHANNEL EXCAVATION

The shoal a t S a i n t Jean c o n s t i t u t e s a n a t u r a l b a r r i e r i n t h e r i v e r . The e f f e c t i v e

I l e n g t h i s a @ 3,500 f e e t and i t func t i ons as a n a t u r a l w e i r t o c o n t r o l o u t f l o w s from Lake Champlain. r e g u l a t i o n scheme u l d r e q u i r e a channel c u t th rough t h i s shoal t o p rov ide increased c annel c a r r y i n g c a p a c i t y . To p reven t minimum l a k e l e v e l s f rom dropp ing below n a t u r a l e l e v a t i o n s and t o ensure p r e r l a k e l e v e l management, an a r t i f i c i a l c o n t r o l would be necessary.

a 3.2 Excavat ion Dimensions

I The amount o f shoal excavat ion would i n f l u e n c e t h e r e d u c t i o n i n l a k e l e v e l s and the channel dimensions, p a r t i c u l a r l y t he bottom e l e v a t i o n , a r e impor tan t because o f p o s s i b l e e f f e c t s on e x i s t i n g works i n t h e r i v e r . The o r i g i n a l channel d redg ing proposed i n 1937 was

I f o r a 400 - foo t wide channel t o e l e v a t i o n 79.0 f e e t GSC. Var ious p o s s i b l e channel c u t con- f i g u r a t i o n s have been s tud ied . The minimum bottom e l e v a t i o n cons idered was 83.0 f e e t GSC because of e x i s t i n g s t r u c t u r a l r e s t r i c t i o n s . The maximum w i d t h cons idered was 700 f e e t due t o r e s t r i c t i v e r i v e r w id ths . (See F igu re 10)

I A l t e r n a t i v e channel c u t c o n f i g u r a t i o n s w i t h bot tom e l e v a t i o n s o f 83.0, 84.0 and 85.0 f e e t GSC, and w id ths o f 500, 600 and 700 fee t were eva luated. The q u a n t i t y o f c u t was computed f o r each a l t e r n a t i v e and t h e e f f e c t on Lake Champlain l e v e l r e d u c t i o n was d e t e r - mined by backwater a n a l y s i s a t f l o w s o f 10,000 and 40,000 c f s . The r e s u l t s a r e shown i n F i g u r e 11 . seen i n t h e f i g u r e , t h e cha-creasingly e f f e c t i v e u n t i l excava- . . t i o n o f ar&00,000 c W y a r d s T w h i c h p o i n t a c o n s i d e r a e in-s -a1 I lake leve? r e d u c t i o n , p a r t i c u l a r l y a t t h e 40,000 c E t l o w . lne-han- nel ' c u t dimensions r e f l e c t i n g t h i s excavat ion a r e as f o l l o w s :

channel bot tom e l e v a t i o n - f t GSC 83 84 8 5 channel w i d t h - f t 500 600 700 q u a n t i t y o f c u t - CY 375,000 356,OGO 320,000

I The q u a n t i t i e s t o be excavated were computed from c ross -sec t i ons surveyed i n A p r i l 1977 .by Environment Canada. The va lues agree c l o s e l y w i t h those computed i n t h e 1972 Quebec Study based on 1937 surveys.

The f i g u r e s d i f f e r cons ide rab l y f rom t h e va lues conta ined i n t h e 1974 ICREB Report which were c a l c u l a t e d us ing soundings f rom 1972-73 surveys. A comparison o f these soundings w i t h those undertaken i n 1937 and 1977 show d f f f e r e n c e s i n r i v e r bot tom e leva -

I t i o n s o f up t o two fee t , w i t h t h e 1972-73 values h ighe r . The d i f f e r e n c e i n q u a n t i t i e s t h e r e f o r e r e f l e c t t h i s e l e v a t i o n d i f f e r e n t i a l .

- The fo rego ing a n a l y s i s i n d i c a t e s t h a t any o f t he t h r e e channel c u t c o n f i g u r a t i o n s

I a r e n e a r l y hydrau l i c a l l y e q u i v a l e n t and would be s u i t a b l e t o p r o v i d e t h e increased channel

f

I d i n a l l e n g t h o f t h e r i v e r o f approx imate ly 8,000 f e e t f rom near Highway 35 c ross ing upstream t o a p o i n t ( F i g u r e 10) near t he S a i n t Jean mar ina. F igu re 12 shows water su r face

I p r o f i l e s under dredged c o n d i t i o n s . Reference t o t h i s p r o f i l e w i l l show t h e e f f e c t o f Lake Champlain 1 eve1 s w i t h o u t a c o n t r o l s t r u c t u r e .

-N

UPSTREAM LIMIT OF DREDGING 7 0 0 ' WIDE DREDGED

CHANNEL EL 8 5 . 0 '

DOWNSTREAM LIMIT OF DREDGING

DISTANCE FROM INTERNATIONAL BORDER IN FEET X 1000

0 8 0 0 1600 2 4 0 0 3 2 0 0 4 0 0 0

SCALE IN FEET

. PLAN AND PROFILE DREDGED CHANNEL

PnysicAL ASPECTS COMMITTEE F14. 10

3.3 Excavat ion Procedures

The m a t e r i a l t o be removed f o r t h e channel c u t has been i d e n t i f i e d as a dense s i l t y t i l l w i t h s tandard p e n e t r a t i o n i n d i c e s v a r y i n g from a minimum o f 20 i n t h e upper l a y e r s , t o over 50 i n t h e l ower l a y e r s . I n g rada t i on , t h e mat.eria1 v a r i e s f rom s i l t t o s i l t y sand w i t h g r a v e l . Boulders up t o 24 inches i n d iameter a r e a l s o found i n t h e m a t e r i a l .

The depth of m a t e r i a l t o be removed v a r i e s from two t o e i g h t f e e t . The o v e r l y i n g depth o f water would va ry depending on t h e t i m e o f yea r and va ry between 5 and 15 f e e t w i t h an average o f 8 f e e t . Average f l ow v e l o c i t y i s i n t h e o rde r o f f o u r f e e t per second. A s p o i l area between t h e Chambly Canal and t h e main r i v e r channel i s a v a i l a b l e f o r d e p o s i t i n g t h e removed ma te r i a l . ( F i g u r e 10)

The method f o r removing t h e m a t e r i a l f rom the channel c u t has been g i ven se r i ous c o n s i d e r a t i o n and persons exper ienced i n dredg ing ope ra t i ons have been consu l ted on the s u b j e c t . Severe r e s t r i c t i o n s due t o l o c k w i d t h and n a v i g a t i o n depths i n t h e Chambly Canal would l i m i t t h e s i z e o f f l o a t i n g equipment t h a t c o u l d be brought on to t h e s i t e . I n add i - t i o n , sha l l ow o p e r a t i n g depths slid h i g h v e l o c i t i e s i n t h e shoal area would present d i f f i - c u l t i e s when o p e r a t i n g d i p p e r o r s u c t i o n dredges and dump scows.

One method suggested i s making use o f convent iona l equipment such as h y d r a u l i c backhoes, b u l l d o z e r s and dump t r u c k s , work ing f rom temporary causeways b u i l t i n t o t h e r i v e r w i t h r i v e r b e d m a t e r i a l . The dyke o r causeway would a c t as a roadway on which a backhoe c o u l d c a r r y o u t t h e r e q u i r e d depth of excavat ion w i t h i n i t s reach. I t would a l s o remove t h e dyke as i t r e t r e a t e d . The s p o i l would be hauled away i n s tandard dump t r u c k s . Th i s method c o u l d p r o v i d e cons ide rab le f l e x i b i l i t y i n schedu l ing , p roduc t i on d i sposa l , e t c . I n a d d i t i o n , i t would a l l o w f o r g r e a t e r o p p o r t u n i t y f o r compe t i t i on by a l a r g e number o f p r i v a t e c o n t r a c t o r s . To be e f f e c t i v e , t h i s method would r e q u i r e t h e r i v e r b e d m a t e r i a l t o be s u i t a b l e t o p rov ide t h e r e q u i r e d s t a b i l i t y on which equipment cou ld work. A program t o t e s t t h e dredg ing method should be undertaken b e f o r e c o n s t r u c t i o n begins. It would d e t e r - mine t h e f e a s i b i l i t y o f t h e method and p r o v i d e cos ts as w e l l as o t h e r i n f o r m a t i o n f o r p r o s p e c t i v e b idde rs .

Schedul ing o f d redg ing ope ra t i ons would be dependent on the r e g u l a t i o n s t r u c t u r e chosen. The phasing w i t h t h e t h r e e a l t e r n a t i v e s i s desc r i bed i n t h e a p p l i c a b l e sec t i ons .

3.4 Impacts on Adjacent S t r u c t u r e s

The excavat ion o f a channel i n t h e reach o f r i v e r cons idered would a f f e c t some e x i s t i n g works. The two main water i n t a k e s f o r I b e r v i l l e and S a i n t Jean a r e l o c a t e d upstream o f any proposed excavat ion and would n o t be a f f e c t e d . There a r e two o t h e r p r i v a t e water i n takes , i n c l u d i n g one l o c a t e d i n t h e proposed d i sposa l area. I n t e r f e r e n c e t o these would be minor . I b e r v i l l e and S a i n t Jean a l s o have a t o t a l o f 16 sewer o u t l e t s d i s c h a r g i n g d i r e c t l y i n t o t h e r i v e r , 12 on t h e I b e r v i l l e s i d e and f o u r on t h e S a i n t Jean s i d e . A l l o f these o u t l e t s d ischarge near t h e r e s p e c t i v e banks o f t h e r i v e r and do n o t c o n s t i t u t e a s e r i o u s o b s t a c l e t o dredg ing. It should be noted t h a t a c t i o n on a request f rom t h e C i t y o f S a i n t Jean f o r a permi t t o b b i l d a water o r sewage t rea tmen t p l a n t i n t h e s o i l d i sposa l area has been postponed i n d e f i n i t e l y . B e l l Canada has t h r e e cab les b u r i e d i n t h e bed o f t h e R i c h e l i e u R i v e r between t h e CPR and Gouin b r i dges . These would r e q u i r e r e l o c a t i n g o r r e t r e n c h i n g t o a deeper l e v e l .

An a d d i t i o n a l i n t e r f e r e n c e f rom a p r o j e c t would be t o t h e ee l f i s h e r y which c o n s i s t s o f a w e i r and assoc ia ted ee l t r a p s l o c a t e d about h a l f a m i l e downstream o f t h e CPR b r i dge . The f i s h e r y would r e q u i r e r e l o c a t i o n because o f increased water depths and g e n e r a l l y u n s u i t a b l e c o n d i t i o n s f o r t r a p p i n g c rea ted by dredg ing and s t r u c t u r e ope ra t i on . An a l t e r - n a t i v e l o c a t i o n i s downstream o f F rye rs I s l a n d Dam where sha l l ow f a s t sec t i ons o f r i v e r e x i s t s u i t a b l e f o r such a purpose.

The o t h e r main s t r u c t u r e s a r e t h e two b r i dges c ross ing between S a i n t Jean and I b e r v i l l e . The Gouin highway b r i d g e i s i n t he s e c t i o n o f r i v e r where excavat ion volumes t o e l e v a t i o n 85.0 f e e t GSC would be i n s i g n i f i c a n t and t h e r e f o r e t h e b r i d g e founda t i on would n o t be a f f e c t e d . The CPR b r i d g e may r e q u i r e up t o two f e e t o f excavat ion t o ach ieve t h e

reclu'i~.c:ti c t l i ~ l ~ l ~ ~ l (1 i ~ ~ ~ o r i ! ; i o n s . TI\(? t ' o ~ ~ ~ r ( l o t . i o t ~ 01' t h e CI'R b r i tlqe cull.; i z 1,s o f c o n c r c t c 11 ic't.. . fotrntlccl on bedrock or. or) t h e tlclrsr: t i l l c\c l )os i 1:s ovct.1.y i r lq t)etlr-ock. A l t h o t ~ g t i i t i s t ~ o ( . exl)ec:ted t h a t any pt-oblenrs would I)(! caused t,o t h i s founclat. ion, c o t ~ s u l t ; d t i o n s s h o u l d rlc!vot.- t h e l e s s be he1 d w i t h Canadian P a c i f i c R a i l r o a d personne l t o c l e t e r r ~ ~ i t i e t h e i r v iews .

When e s t i m a t i n g d r e d g i n g c o s t s , a u n i t based on d i s c u s s i o n s w i t h government a g e n c i e s T a b l e s 4 and 5 p r o v i d e a summary and d e t a i l s o f t h e c o s t s f o r e x c a v a t i n g t h e c h a n n e l . I n c l u d e d a r e a l l o w a n c e s f o r r e l o c a t i n g t h e e e l f i s h e r y , m o d i f i c a t i o n s t o t h e t e l e p h o n e c a b l e s and m i s c e l l a n e o u s work on w a t e r i n t a k e s , e t c .

TABLE 4 SUMMARY OF ESTIMATED COSTS

FOR DREDGING

1. Construction Facilities 2. Lands and Damages 3. Channel Excavation 4. Contingencies - 15%

Total Direct Cost

5. Preliminary Studies 6. Engineering Supervision and Administration

Total Construction Cost

7. Interest During Construction

Capital Cost

Annual Cost

1. Interest and Amortization - 50 years at 74%

2. Operation and Maintenance

Total Annual Cost

Item

1. CONSTRUCTION FACILITIES Mobilization, land rental demobilization

Unit ,Quantity Unit Price

2. LANDS AND DAMAGES Relocation of Bell cables job Rebuilding of eel fishery j ob Miscellaneous, water intakes j ob etc.

3. CHANNEL EXCAVATION W N Including disposal hauling - c.y. I Access routes, disposal dykes job

4. CONTINGENCIES 15% ON 2,510,000

TOTAL DIRECT COST

PRELIMINARY STUDIES

6. ENGINEERING SUPERVISION AND ADMINISTRATION

TOTAL CONSTRUCTION COST

7. INTEREST DURING CONSTRUCTION (7$%)

CAPITAL COST

TABLE 5 DETAILED COST ESTIMATE

FOR DREDGING

Item Cost Feature Cost

L. S. 20,000 L.S. 200,000 L.S.. 20,000

SECTION 4 FIXED CREST STRUCTURE

4.1 General Description

The s i t e f o r the fixed c r e s t s t ruc ture i s on the Richelieu River a t Saint Jean about midway between the Canadian Pac i f ic Railway and Gouin bridges (Figure 13 ) . This , location represents the widest r i ve r section in the shoal area. Founded on t i l l overburden, the s t ruc ture would be constructed of reinforced concrete, and have a length of 1,580 f e e t , a base width of 45 f e e t and a c r e s t elevation of 92.85 f ee t GSC (93.20 f e e t USGS). Channel dredging downstream of the s t ruc ture will have the e f f ec t of lowering backwater levels in order t o permit the s t ruc ture to function f ree ly as a weir. Upstream, dredging will eliminate any poss ib i l i ty of the shoal rais ing w a t e r leve ls any higher than those dictated by the capacity of the weir ( see Figures 10 and 15 ) . 120 operational procedures a r e possible with t h i s s t ruc ture . I t s performance depends only on i t s capacity to pass flows of d i f f e r en t magnitudes.

4.2 Geologic Features

Figure 16 shows a subsurface p ro f i l e on the l i ne investigated in the f i e l d in 1976. The s ix boreholes a r e also shown. As the p ro f i l e ind ica tes , the material overlying bedrock i s a glacial t i l l which i s generally in a compact to very dense s t a t e ; however, near the west shore in the area of boreholes F-21, F-22 and F-25, the upper part of the t i l l stratum was observed t o be generally loose. Also near the west shore in boreholes F-25 and F-21, a pocket of s i l t y clay was encountered in the t i 1 1 stratum near elevations 81 f e e t and 79 f e e t GSC. This s i l t y clay pocket, about 4 .5 f e e t thick, does not extend across the r i ve r . Bedrock consisting of a black clayey shale, i s present a t elevation 70 f e e t GSC o r lower.

4 .3 Physical Model Tests

I n i t i a l t es t ing was conducted t o determine the e f f ec t s of the presence of a weir of various types of construction. An earthen broad-crested shape composed largely of undredged natural r i ve r bottom and having a top width of 150 f e e t , with s ide slopes of approximately one foot ve r t i ca l l y to 30 f e e t horizontal ly, was constructed in the model. Velocity t e s t s indicated tha t the const i tuent material would erode under flood conditions. A narrower weir having a top width of 20 f e e t with s ide slopes of one foot ve r t i ca l l y to two f e e t qnd three f ee t horizontally and e i t he r an armor stone or concrete surface was

Based on o f f i ce studi.es indicating the des i r ab i l i t y of a more permanent s t ruc ture , a concrete weir havinq an improved discharge coef f ic ien t was then selected fo r detai led study. The sectional-model constructed f o r t h i s purpose was tes ted to determine i t s d i s - charge capacity and overflow charac ter i s t ics . These t e s t s indicated sa t i s fac tory overflow performance with l i t t l e or no e f f ec t of downstream submergence. The weir discharge capacity was established based on the coef f ic ien ts developed f o r the range of upstream leve ls .

Further tes t ing of the concrete weir sectional model was conducted to determine the d iss ipa t ion cha rac t e r i s t i c s of flow on the downstream side of the weir c r e s t . If Fryers Island Dam were t o be operated a t a minimum pool level for navigation purpose,, the ta i lwater to the weir would be such t h a t the hydraulic j u m p would always s t a r t on the downstream face of the weir. Were natural t a i lwater levels t o e x i s t , the s t a r t of the j u m p would move close to the downstream edge of the weir fo r low discharges, indicating the

PLUO RETAINED I N NATURAL CON ITION 0 R l N I CONITRUOTION Of JIYLD oRYOT O ~ R U C I U R I

PLUO RETAINED I N NATURAL CONDITION DURlNQ CON8TRUCTION O f *&TED STRUCTURE

1st STAGE COFFERDAM CREST EL.IT.0

H.W.L=96.5 FOR

CREST EL. 92.

6. FILTER UYER

CONCRETE WElR - SECTION A - A

'-! W IN FELT

I

PLAN VIEW

700' WIDE DREDGED CHANNEL TO EL.850

ORIGINAL SURFACE PROFILE ADOlTlONAL DREDGING TO EL.05.0

EL. 100.0

-CREST EL.02.W

TLL wlTn SILTY -EL. 83.0 CLAY Urn .TO ELEULTWm N.6

CONCRETE WEIR - UPSTREAM ELEVATION 2 m m o m

Mom2QITAL - IQIL: ELEWTIONS TO G.SC M T U

VERTICAL m-m F0(1 UI'MTUY ADO 0.31 FEET

-

IMTERNATK)MM CMAMCLUM-RICMELIEU BOARD

RICMKLI~U RIVER REOULATOlY WORKS - FIXED CREST STRUCTURE

PLAN, ELEVATION AND SECTION

CWY~ICAL r s r c c n COMY ITTEE CIQ. 18

FIG. 15

View o f Proposed S i t e f o r F ixed Cres t S t r u c t u r e

NOTE: ELEVATIONS TO G.S.C. DATUM FOR U.S. DATUM ADD 0.37 FEET SCALE

I INTERNATIONAL CHAMPLAIN - RlCHELlEU BOARD I

FIXED CREST STRUCTURE SITE

1 GEOWGICAL PROFILE

PHYSICAL ASPECTS 1 COMMITTEE I I FIO. 16 1

WATER SURFACE PROFILE FOR DREDGED CHANNEL WITH FIXED CREST STRUCTURE


LAKE CHAMPLAIN STAGE-DISCHARGE RELATIONSHIP

FIXED CREST WEIR AT C 4

7 - 0 -

92 I 1 I I I - I I I 0 5 10 15 20 25 30 35 40

DISCHARGE IN C.F.S. x 1000

n e c e s s i t y o f p r o v i d i n g downstream channel bo t to i l l p r o t e c t i o n . F o r a l l c o n d i t i o n s , t h e h y d r a u l i c jump wou ld c o n t i n u e p a s t t h e downstream edge o f t h e w e i r , a l s o i n d i c a t i n g t h e n e c e s s i t y o f downstream b o t t o m p r o t e c t i o n . T h e r e f o r e , two m o d i f i c a t i o n s t o e x t e n d t h e c o n c r e t e t o e o f t h e w e i r f i v e f e e t f u r t h e r downstream were t e s t e d : a h o r i z o n t a l e x t e n s i o n , and an i n c l i n e d e x t e n s i o n w i t h an upward ang;e o f t e n degrees . E i t h e r change wou ld success- f u l l y l i f t t h e b o t t o m j e t , r e s ~ r l t i n g i n reduced s c o u r i n g a c t i o n downstream. The h o r i z o n t a l e x t e n s i o n was s e l e c t e d because o f i t s s i ~ n p l i c i t y i n c o n s t r u c t i o n . The l a b o r a t o r y s t u d i e s o f r i p r a p r e q u i r e m e n t s t o p r e v e n t e r o s i o n o f t h e downstream t o e r e s u l t e d i n t h e s e l e c t i o n o f a 1 5 - i n c h t h i c k b l a n k e t . The s t o n e wou ld e x t e n d f o r a l e n g t h o f 50 f e e t be low t h e w e i r .

T e s t i n g o f cof ferdam s t a g i n g was per fo rmed i r l o r d e r t o e s t a b l i s h t h e p r o c e d u r e s necessary t o e n s u r e t h a t c o n t r o l o f l a k e l e v e l s i s n o t l o s t d u r i n g c o n s t r u c t i o n , as w e l l as t o d e t e r m i n e r e q u i r e m e n t s t o r e d u c e any t h r e a t e n i n g backwate r e f f e c t s . To t h i s end, i t was d e t e r m i n e d t h a t o n l y two c o f f e r d a m s w o u l d be r e q u i r e d a f t e r t h e channel d r e d g i n g was accompl i shed . Stage I w o u l d b e g i n w i t h t h e c o n s t r u c t i o n o f a c o f f e r d a m f r o m t h e r i g h t bank o f t h e channel e x t e n d i n g a b o u t ha l f -way i n t o t h e r i v e r . Upon c o m p l e t i o n o f t h e f i r s t s t a g e work, t h e c o f f e r d a m wou ld be removed p r i o r t o t h e s p r i n g f l o o d season, and Stage I 1 c o f f e r - dam c o n s t r u c t e d d u r i n g t h e f o l l o w i n g sumrner t o comp le te t h e work t o t h e o p p o s i t e bank. Stage I 1 must be c o m p l e t e d b e f o r e t h e f o l l o w i n g s p r i n g r u n o f f season. The l a b o r a t o r y s t u d i e s demons t ra ted t h e need t o r e t a i n a p o r t i o n o f t h e channel i n an undredged c o n d i t i o n u n t i l c o m p l e t i o n o f t h e w e i r . T h i s " p l u g " wou ld m a i n t a i n n e a r n a t u r a l ups t ream l e v e l s w h i l e d r e d g i n g o p e r a t i o n s and c o n s t r u c t i o n o f t h e w e i r a r e underway. The " p l u g " wou ld have a l e n g t h o f 475 f e e t and be a t a d i s t a n c e o f a p p r o x i m a t e l y 1,000 f e e t downstream o f t h e w e i r . The " p l u g " i s t o be d redged o n l y a f t e r c o m p l e t i o n o f t h e w e i r .

9.4 R e g u l a t i o n A n a l y s e s - No o p e r a t i o n a l p r o c e d u r e s a r e p o s s i b l e w i t h t h e f i x e d c r e s t s t r u c t u r e ; i t wou ld

o p e r a t e a t a f i x e d c o n t r o l e l e v a t i o n . The e f f e c t on Lake Champla in l e v e l s w o u l d be a f u n c t i o n o f t h e s e l e c t e d c r e s t e l e v a t i o n and r e s u l t i n g s t a g e d i s c h a r g e r e l a t i o n s h i p o f t h e w e i r . The r e g u l a t i o n a n a l y s e s c o n s i s t e d o f a s s e s s i n g t h e e f f e c t on t h e s t a g e h y d r o g r a p h o f t h e l a k e by t h e p r e v i o u s l y d e s c r i b e d p r o c e d u r e f o r d i f f e r e n t w e i r c r e s t e l e v a t i o n s . I n t h e s e l e c t i o n p r o c e s s , t h e o b j e c t i v e was t o s i m u l a t e a s c l o s e l y as p o s s i b l e n a t u r a l l e v e l s o f t h e l a k e d u r i n g medium and l o w p e r i o d s w h i l e , a t t h e same t i m e , l o w e r i n q f l o o d

e l e v a t i o n o f 92.85 - f e e t GSC was d e t e r m i n e d t o be s a t i s f a c t o r y . F i q u r e s 19, 20 and 21 c o n t a i n h y d r o g r a p h s showing t h e e f f e c t s o f channel d r e d g i n g and t h e f i x e d c r e s t c o n t r o l s t r u c t u r e on l a k e l e v e l s f o r t h e t h r e e d i f f e r e n t c o n d i t i o n s : a t y p i c a l h i g h y e a r , a t y p i c a l l o w y e a r , an3 a normzl y e a r . A l s o s t a g e and f l o w d u r a t i o n c u r v e s f o r t h i s s t r u c t u r e a r e showno on F i g u r e 22 f o r p e r i o d o f r e c o r d 1938-1976.

4.5 In ipac t o f S t r u c t u r e on Lake Levels , - A t t h e c r e s t e l e v a t i o n o f 92.85 f e e t GSC, t h e f i x e d - c r e s t s t r u c t u r e p r o v i d e s a

s i g n i f i c a n t l o w e r i n g o f f l o o d peaks w h i l e a t . t h e same t i m e m a i n t a i n i n g t h e l o w e r l e v e l s c l o s e t o t h e n a t u r a l r a n g e . A s t u d y o f t h e hydrographs r e s u l t i n g f r o m t h e r e g u l a t i o n a n a l y s e s shows a l o w e r i n g o f a l l n a t u r a l l e v e l s above e l e v a t i o n 95.0 f e e t USGS. The inaxinium l o w e r i n g o f h i s t o r i c a l f l o o d peaks amounts t o 1 . 4 f e e t f o r 1976, and 1 . 6 f e e t f o r 1974.

4 . 6 C o n s t r u c t i o n Procedures-

The f i x e d c r e s t s t r u c t u r e wou ld be c o n s t r u c t e d i n t h e d r y i n a dewate red e x c a v a t i o n p r o t e c t e d by c o f f e r d a m s . I n o r d e r t o m a i n t a i n s a t i s f a c t o r y f l o w c o n d i t i o n s and w a t e r l e v e l s o f Lake Champla in, c o n s t r u c t i o n i n two s t a g e s wou ld be r e q u i r e d e x t e n d i n g o v e r two seasons. R e s u l t s o f p h y s i c a l model t e s t s d e s c r i b e d p r e v i o u s l y d e t e r m i n e d t h e sequence o f c o n s t r u c t i o n n e c e s s a r y i n c o n j u n c t i o n w i t h t h e channe l d r e d g i n g . A p r e l i m i n a r y c o n s t r u c - t i o n s c h e d u l e i s i n c l u d e d . I t i s 1 i k e l y t h e c o f f e r d a l n s c o u l d be b u i l t w i t h e x c a v a t e d m a t e r i a l f r o m t h e r i v e r b o t t o m . A t o t a l o f a p p r o x i i n a t e l y 60,000 c u b i c y a r d s wou ld be r e q u i r e d f o r b o t h s t a g e s .

U J

FEB M R R Fl P R M f l Y J U N J L Y R U G SEP O C T N O V DEC J R N

\ \---

DIJRPTTON ANALYSIS -- - .----SFC.E

FOP W R SCtIEME

])I SCHARGE

MlU RNNURL Y C R 1937 10 1976 I n l N RNNURL l L R R I 9 3 7 10 1976

.- = -8, . . ":'y-.-- 3 , ,

- -. -. - -- - . . . . . . .

*.w d.00 4b.w r\.oo A.00 8b.m ,'.‘a RT OR O f L O Y IUOICRTIO LEVEL

FIG. 22

The s t r u c t u r e , w h i c h wou ld r e q u i r e abou t 25.090 c u b i c y a r d s o f c o n c r e t e . c o u l t l I,( poured i n s e c t i o n s o f a b o u t 30 t o 40 f e e t . The p r e l i n ~ i n d r y d e s i g n and q u a n t i t i e s c a l l l o r e x c a v a t i n g t h e c l a y p o c k e t n e a r t h e l e f t bank and f o u n d i n g t h a t p o r t i o n on t h e u n d e r l y IIU)

t i l l ; however, f u r t h e r i n v e s t i g a t i o n and t e s t i n g may show t h e s i l t y c l a y s a t i s f a c t o r y a<, , I

f o u n d a t i o n m a t e r i a l . The compact t o v e r y dense t i l l i s c o n s i d e r e d adequa te f o r t h e c o n t a c t p r e s s u r e s t h a t w o u l d be d e v e l o p e d and s e t t l e m e n t i s e x p e c t e d t o be s m a l l .

4 .7 C o s t E s t i m a t e s

E s t i m a t e d c a p i t a l c o s t o f t h e f i x e d c r e s t s t r u c t u r e i s $4.6 m i l l i o n , e x c l u s i v e o f t h e channe l d r e d g i n g . T a b l e 6 p r o v i d e s a summary o f e s t i m a t e d c a p i t a l and annua l c o s t s . D e t a i l e d e 5 t i m a t e s a r e i n c l u d e d i n T a b l e 7 . Cos ts and b e n e f i t s f o r t h i s scheme a r e shown i n T a b l e 3.

I \ I

FIG. 23 I

TABLE 6

SUMMARY OF COST ESTIMATES FIXED CREST STRUCTURE

Construction Facilities $ 150,000 Lands and Damages 50,000 Unwatering 631,600 Excavation ' 388,020 Fill 127,800 Concrete (reinforced) 1,887,250 Buildings and Utilities 100,000 Contingencies 500,200

Total Direct Cost

Preliminary Studies Engineering and Design


Interest During Construction

Capital Cost

~nnual Cost

Interest and Amortization Interim Replacement Operation and Maintenance Administration and General Expense

Total Annual Cost

352,230 nil 10,000

TABLE 7

DETAILED COST ESTIMATE FIXED CREST STRUCTURE

Quant i ty Unit p r i c e 1tem c o s t . .

Item Unit Fea tu re Cost

1. CONSTRUCTION FACILITIES Mobi l iza t ion , l and r e n t a l

demobi l iza t ion , e t c . job L.S.

2. LANDS AND DAMAGES land purchase L.S. job

3. W A T E R I N G Cofferdam 1st s t a g e

f i l l , impervious I f i l l , rock r i p r a p P M Cofferdam 2nd s t a g e

4.00 125,880 10.00 7,500 L.S. 75,000 L.S. 300,000

- - I f i l l , impervious c.y.

c.y. job job

f i l l , rock r i p r a p Pumping Cofferdam removal

4. EXCAVATION a d d i t i o n a l dredging c.y. 68,730 4.00 274,920 foundat ion c.y. 16,090 5.00 80,450 downstream b l a n k e t c.y. 6,530 5.00 32,650 388,020

FILL b a c k f i l l a t w e i r , s e l e c t e d r i p r a p channel and s l o p e s f i l t e r r i p r a p bedding

CONCRETE ( r e in fo rced ) w e i r and foundat ion r e t a i n i n g w a l l s

-c ' . - ; , & & ' . * - I - I 1

j 5

DETAILED COST ESTIMATE FIXED CPEST STRUCTURE

I t e m U n i t Q u a n t i t y U n i t P r i c e I t e m C o s t F e a t u r e C o s t

7 . BUILDINGS AND UTILITIES p a r k i n g service area j o b L.S.

8. CONTINGENCIES 15% o n 3 , 3 3 4 , 6 7 0 5 0 0 , 2 0 0

TOTAL DIRECT COST

9. PRELIMINARY STUDIES

10. ENGINEERING AND DESIGN SUPERVISION AND ADMINISTRATION

I

P a TOTAL CONSTRUCTION COST I

1 2 . INTEREST DURING CONSTRUCTION (74%)

1 CAPITAL COST L

i

SECTION 5 N E l l r:ATED STRUCTURE

5.1 Genera l D e s c r i p t i o n

5.1.1 S i t e L o c a t i o n

The s i t e f o r a p roposed new g a t e d s t r u c t u r e i s a b o u t 3,000 f e e t downstream f r o m t h e Canadian P a c i f i c R a i l w a y b r i d g e a t S a i n t Jean. T h i s l o c a t i o n was s e l e c t e d i n t h e Quebec s t u d y o f 1972 because o f f a v o u r a b l e t o p o g r a p h i c , g e o l o g i c a l and h y d r a u l i c c o n d i t i o n s , and minimum p r o p e r t y e x p r o p r i a t i o n a t t h e t i m e . Subsequent s t u d i e s and i n v e s t i g a t i o n s s i n c e t h a t t i m e i n d i c a t e i t i s s t i l l a f e a s i b l e l o c a t i o n . A t t h e s i t e , t h e l e f t bank i s b o r d e r e d b y t h e Chambly Canal dyke w i t h a t o p e l e v a t i o n o f a b o u t 100 f e e t GSC. The r i g h t bank i s b o r d e r e d by a r o a d (Quebec Route 21) w i t h a t o p e l e v a t i o n o f 101 f e e t GSC. The r i v e r w i d t h a t t h e s i t e i s a b o u t 800 f e e t .

5 .1.2 S t r u c t u r e

The p roposed s t r u c t u r e wou ld c o n s i s t o f by 1 4 - f o o t p i e r s f o r an o v e r a l l w i d t h between---a s k c t i o n s c o n f i n e d by r e t a i n i n g w a l l s wou ld f o r m t h e c l o s u r e on b o t h banks. The s t r u c t u r e wou ld have a base w i d t h o f 34 f e e t and a 3 1 - f o c t l o n g s t i l l i n g b a s i n wou ld be l o c a t e d i m m e d i a t e l y downstream. An 1 8 - f o o t w i d e roadway a t e l e v a t i o n 106.- f e e t GSC wou ld span t h e e n t i r e s t r u c t u r e . SC) wou ld be t h e same as t h e b o t t o m e l e - v a t i o n o f t h e d r e d g show t h e g e n e r a l a r rangement and s e c t i o n a l and e l e v a t i o n v i e w s .

5 .1 .3 Gates

C o n s i d e r a b l e i n v e s t i g a t i o n was c a r r i e d o u t i n p r e v i o u s s t u d i e s t o d e t e r m i n e t h e mos t s u i t a b l e g a t e t y p e f o r such a s t r u c t u r e . Those i n v e s t i g a t i o n s l e d t o t h e a d o p t i o n o f t h e s e c t o r t y p e g a t e h i n g e d downstream and t h e same g a t e t y p e i s used i n t h i s s t u d y . The l e n g t h used i s 100 f e e t w h i c h i s c o n s i s t e n t w i t h s t a n d a r d s i z e s m a n u f a c t u r e d t o d a y . The . . h e i g h t wou ld depend on t h e r e g u l a t i o n scheme adop ted , bwt i i ~ r ITWWIWM z i 7 e f o r

ximuni o f 1 0 f d ~ a t e s o f t h i s t y p e and t S t . Ours Dam, a l s o on t h e R i c h e l i e u R i v e r .

5 .2 G e o l o g i c F e a t u r e s

S u b s u r f a c e i n v e s t i g a t i o n s c o n s i s t i n g o f e i g h t d r i l l h o l e s were c a r r i e d o u t d u r i n g O c t o b e r and November 1973 a t an a x i s a p p r o x i m a t i n g t h a t o f t h e p roposed g a t e d s t r u c t u r e . A g e o l o g i c a l s e c t i o n i s p r o v i d e d i n F i g u r e 29. T h e ' e n t i r e l a y e r o f o v e r b u r d e n , w h i c h has been i d e n t i f i e d a s a dense s i l t y g l a c i a l t i l l c o n t a i n i n g b o u l d e r s up t o one f o o t i n s i z e , i s q u i t e homogeneous. The t i l l t h i c k n e s s v a r i e s between 16 and 38 f e e t . A l l h o l e s were d r i l l e d t o bedrock , w h i c h i s s h a l e h o r i z o n t a l l y bedded and a t p l a c e s c o n s i d e r a b l y wea thered and f i s s u r e d .

5 .3 P h y s i c a l Model T e s t s

The f i r s t s e r i e s o f t e s t s o f t h i s s t r u c t u r e were f o r t h e purpose o f examin ing t h e p e r f o r m a n c e c h a r a c t e r i s t i c s o f a dam h a v i n g f i v e s e c t o r g a t e s , each 100 f e e t l o n g , i n t h e d redged c h a n n e l . R e s u l t s o f t h e s e i n i t i a l t e s t s i n d i c a t e d t h a t t h e head l o s s e s t h r o u g h t h e s t r u c t u r e were e x c e s s i v e and t h a t t h e f l o w p a t t e r n s were u n d e s i r a b l e . T h e r e f o r e , an a d d i t i o n a l 1 0 0 - f o o t l o n g g a t e was added t o t h e model and t h e s t r u c t u r e r o t a t e d c o u n t e r - c l o c k w i s e a b o u t f o u r degrees . S t u d i e s o f t h e r e v i s e d a r rangement i n d i c a t e d s a t i s f a c t o r y per fo rmance and r e s u l t e d i n t h e d e c i s i o n t o use s i x s e c t o r g a t e s i n s t e a d o f t h e f i v e o r i g i n a l l y p roposed . I n a n o t h e r t e s t , t h e s t r u c t u r e was moved ups t ream a p p r o x i m a t e l y

DREDGED CHANNEL

SEE FIG 13 FOR RETENTION O F PLUG DURl NG CONSTRUCTION

OF GATED STRUCTURE

200 FEET

SCALE IN FEET

NOTE: ELEVATIONS TO G.S.C. DATUM

INTERNATIONAL CHAMPLAM-RICHELIEU BOARD

RlCHELlEU RIVER REGULATORY WORKS

GATED STRUCTURE

GENERAL ARRANGEMENT I FOR U S DATUM ADD 0 37 FEET - 5 2 -

PHYSICAL ASPECTS COMMITTEE FIG. 24

1 F L O W SERVICE ROAD

6 7 0 / T U R N I N G A R E A

TRAINING WALL 80 4 +s 14' %IQ 9 100'

69 M

& w EP & - \ f \ / I Y f

rd

U U U U f U I TOP O F P I E R E L 100.0 I I

t?J ??= 69 80 83 6 - 100' W IDE SECTOR GATES

RIPRAP BLANKET BUILDING - CREST ELEVATION AND GATE HEIGHT DEPENDS ON REGULATION SCHE RIPRAP 5 0 ' LENGTH

%? a g- 4 PLAN VIEW

100 5 0 0 100

SCALE IN FEET

GLACIAL T I L L

E ~ , 8 0 , 5 ----- -+- - -- - -- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - I I I 1 I I

E L . 7 2 . 0 - L - L - - - - - - - - - - - - - - - - - - - - ---- ----------------------lJ

--/-- 4 - B

-------- - - - ~ q ~ ~ ~ ~ = ~ / ~ - --- -- ROCK PROFILE -- SCALES mqm- ----

0 10 2 0 3 0 40 50FT. 0 50 100 150 FT.

P - VERTICAL HORIZONTAL

€€€m

DOWNSTREAM ELEVATION VIEWED FROM A-A

I I I I I I I I I I I I I I I

0 O i I

APPROXIMATE BEDROCK SURFACE EL, 60 - - - /\\:/I\ :/I\ = / I \ = / I \ =/I\

SECTION B-B

I I I I 1

SCALE IN FEET

EL. 1 0 0 . 0 _ & -

NOTE: ELEVATIONS TO G.S.C. DATUM

FOR U.S. DATUM ADD 0.37 FEET.

I I I I I I I I I I I I I I I I I I I 1 I I I E L 1 0 6 0

E L 9 9 0 \

INTERNATIONAL CHAMPLAIN- RlCHELlEU BOARD

- - -4

GATED CONTROL STRUCTURE

PLAN, ELEVATION, AND SECTION

PHYSICAL ASPECTS COMMITTEE

FIG. 25

I 'I-

/

lberville I

FIG. 27

View of Proposed Site for New Gated Control Structure

ST. OURS DAM

Figure 28

Downstream V l ew Showi ng Control Gates i n Lower Pos i ti on

WEST

BANK

NOTE : ELEVATIONS TO G.S.C. DATUM

FOR US DATUM ADD 0 .37 ' FEET

SCALE

5 0 100 150 2 0 0 F T

GATED STRUCTURE SITE

GEOLOGICAL PROFILE

I PHYSICAL ASPECTS COMMITTEE ! F I G . 23 I

L A K E CHAMPLAIN STAGE - DISCHARGE RELATIONSHIP

GATED STRUCTURE AT C 27

- 7

- -

z 3

LAKE LEVEL

GATED STRUCTURE ALL GATES OPEN

ST. JEAN SHOAL DREDGED AT EL. 85.0 - 700 ' WIDE

I 1 1

0 5 10 15 20 25 30 35 40

DISCHARGE I N C.F.S. x 1000

1.200 f e e t t o deter t i l ine whether f u r t h e r i~ l ip rove l~ len t i n performance c o u l d be obta ined. Resu l ts o f t h i s t e s t i n d i c a t c d no i~~ lprove l l len t arid l.hc! o r i g i n a l s i t e l o c a t i o n o f t he 5 t t .uc turc was r e t d incd.

Thc! st?c L io l i , ~ l 111odc 1 o f the (ICIIII W i l S Ol)(!t'il I (!(I 1.0 sI:~~(l,y t he h,ytlrau l i c aspects o f l.ti(: !J;I 1es i111d s t i l 1 .ili!j I )asir l pc r fo r~~~ar~ ( : c ! . ' rests o f ! jd 1.o cl i :;charge coc.!ff'-icien t s were Itlade 1.01.

s i x ga te p o s i t i o n s o r ~ d t h e f u l l ran(je o f r i v e r f lows. I)ownstrea~ll c o n d i t i o n s o f e i t h e r i1

n a t u r a l t a i l w a t e r o r t h e pool ob ta ined fro111 operat ior1 o f -the F rye rs I s l a n d Dam f o r n a v i g a t i o n purposes were i nco rpo ra ted i n t h e t e s t s . These s t u d i e s l e d t o t h e i d e n t i f i c a - t i o n o f t he d i scha rge c o e f f i c i e n t s f o r a l l c o n d i t i o n s , thus e s t a b l i s h i n g t h e o v e r f l o w c a p a c i t y of t h e s t r u c t u r e . Tes t i ng of h y d r a u l i c jump c o n d i t i o n s downstream o f t he ga te i n d i c a t e d t h a t t h e jump was n o t conta ined w i t h i n t he s t i l l i n g bas in , t h e tu rbu lence c o n t i n u i n g somewhat downstream. Therefore, s t u d i e s were undertaken t o r e v i s e t h e s t r u c t u r e i n o r d e r t o o b t a i n s a t i s f a c t o r y energy d i s s i p a t i o n . These t e s t s l e d t o t h e development o f an 1 8 - f o o t ex tens ion o f t h e s t i l l i n g bas in f l o o r . A1 though s a t i s f a c t o r y performance i s ob ta ined by l eng then ing t h e basin, t h e h y d r a u l i c jump remains i n t h e t u r b u l e n t range f o r which surface waves can be expected. There fore , t e s t s were conducted t o develop a r i p r a p pad t o p r o t e c t t h e t o e and downstream channel f l o o r . These t e s t s l e d t o t h e development o f a 30- inch t h i c k r i p r a p b lanke t . The s tone i s t o extend f o r a l e n g t h of 50 f e e t downstream o f t h e s t i l l i n g bas in end s i l l .

Cofferdam s t a g i n g t e s t s s i m i l a r t o those f o r t he proposed w e i r were performed i n t h e r i v e r model. Measurements of upstream l e v e l s w i t h t h e model led cof ferdams i n p lace l e d t o t h e ' c o n c l us ion t h a t on1 y two cof ferdams would be r e q u i r e d s ince t h e backwater produced by t h e i r presence would n o t be s u b s t a n t i a l l y h i g h e r than n a t u r a l l e v e l s d u r i n g t h e p re -sp r i ng c o n s t r u c t i o n pe r i ods . The Stage I cofferdam, t o be completed and removed b e f o r e t h e s p r i n g r u n o f f season, would extend f rom the r i g h t bank approx imate ly midway across t h e channel . The Stage I 1 cof fe rdam would complete t h e s t r u c t u r e t o t h e l e f t bank p r i o r t o t h e f o l l o w i n g s p r i n g r u n o f f p e r i o d when i t must be removed. Tests a l s o i n d i c a t e d t h e n e c e s s i t y t o r e t a i n a p o r t i o n o f t h e channel i n an undredged c o n d i t i o n u n t i l comple t ion o f t h e dam. The "p lug " would have a l e n g t h o f 695 f e e t and be a t a d i s t a n c e o f approx imate ly 2,600 f e e t upstream o f t h e dam. The "p lug " i s t o be dredged o n l y a f t e r comple t ion o f t h e dam.

5.4 Regu la t i on Analyses f- A l l t h e r e g u l a t i o n schemes fo rmu la ted f o r a new\gated s t r u c t u r e a r e desc r i bed below.

Some o f t h e schemes were examined f o r comparison p u ~ p o s e s w i t h those designed t o s a t i s f y environmental and o t h e r c r i t e r i a as supp l i ed by t h e Environmental Impacts Committee and t h e Net B e n e f i t s Committee.

Scheme MP - No c o n s t r a i n t s except t o m a i n t a i n minimum water l e v e l o f 94.0 f e e t USGS on l a k e by ga te ope ra t i on . Gates a r e thus f u l l y down most o f t h e yea r .

NF - Gates a r e comple te ly lowered when l a k e reaches e l e v a t i o n 96.0 f e e t USGS a f t e r March 1 ; gates a r e r a i s e d and operated t o r e t u r n l e v e l s t o n a t u r a l when l e v e l s drops t o 97.0 f e e t USGS a f t e r passage of f l ood . Minimum l e v e l 94.0 f e e t USGS i s ma in ta ined hetween September 1 and March 1 .

FC - Gates a r e lowered comple te ly o r i f l a k e l e v e l exceeds 98.5 f e e t USGS. Gat m e t o n a t u r a l when l e v e l drops t o 97.0 f e e t USGS a f t e r passage o f f l o o d . Between ~epfernber 1 and March 1, gates a r e opera ted t o m a i n t a i n minimum water l e v e l i n range between 94.0 f e e t USGS and 94.5 f e e t USGS.

F I - Same as FC above except t h a t ga tes a r e opera ted between September 1 and March 1 t o p r o v i d e n a t u r a l c o n d i t i o n s , w i t h a minimum l e v e l o f 94.0 f e e t r- USGS.

\ - S i m i l a r t o FC except ga tes a r e opera ted t o s a t i s f env i ronmenta l and economic b e n e f i t c r i t e r i a i n t h e f o l l o w i n g way. d a t e s a r e lowered accord ing t o f o r e c a s t s i m i l a r t o FC. ~ f t e r f l o o d peak i s ~ a s s e d and

t a r g e m t i o n of 9875 ' f ee t USGS _ reasons u n t i l f o r t i e t h day a f t e r t h i s

DISTANCE FROM BORDER IN FEET X 1000 '.. .

b e b e n e f i c i a l t h a t l a t e i n t h e season. I n t h i s case, g a t e s a r e n o t

FCE-1 exce-pt s p r i n g t a r g e t l e v e l f o r c r i t e r i a i s 98.0 f e e t

USGS.

As i n d i c a t e d above, schemes FCE-1, FCE-2 and FCE-3 were based on a f o r e c a s t p r o - cedure . T h i s p r o c e d u r e was deve loped t o s i m u l a t e a p r a c t i c a l t y p e o f o p e r a t i o n based on a p r o b a b i l i s t i c f o r e c a s t method b e i n g deve loped by t h e U.S. N a t i o n a l Weather S e r v i c e f o r Lake Champla in. T h i s ex tended s t r e a m f l o w p r e d i c t i o n p rogram i s f u r t h e r d e s c r i h e d i n S e c t i o n 8 o f t h i s r e p o r t .

,

T y p i c a l hydrographs showinq t h e e f f e c t o f d r e d ~ i n g and t h e g a t e d s t r u c t u r e f o r schemes FCE-1, FCE-2 and FCE-3 a r e shown i n F i g u r e s 32 t o 40 and d u r a t i o n c u r v e s i n F i g u r e s 41, 42 and 43.

5 .5 Impac t o f S t r u c t u r e on Lake L e v e l s

,

LRHE CHAMPLAIN STAGE HYOROGRRPH 1965 F C E-1

GATED STRUCTURE S I X SECTOR GRTES 100 F T W I D E ERCH

J A N FEB M A R APR MAY J U N J L Y AUG SEP O C T NOV O E C

o LRKE CHBHPLfl IN STFIGE HYIR$GWRPH 1971 FCE-1 0

I ) 8 t E b ' S T W U C T U R E S I X SECTmR GRTES la61 F T W I B E ERCH

JAN FEB - MAR APR MAY JUN SEP O C T NOV O E C J L Y , AUG L (

0 LAKE CHARPLAIN STAGE HYOROGRAPH 1968 FCE-1

0

GATED STRUCTURE S I X SECTOR GRTES 100 F T W I D E ERCH

JAN FEB MRR FlPR MRY J U N J L Y RUG ' S E P O C T NOV O E C

llF\K.E CHRMPLFlIN STRGE HYDROGRRPH 1965 F C E-2 U

m GRTED S T R U C T U R E S I X S E C T O R GRTES 1 0 0 F T W I D E ERCH

J A N FEB MAR APR MAY J U N J L Y RUG SEP O C T N O V D E C

o LRKE CHRMPLRIN STRGE HYOROGRRPH 1971 F C E-2 U

m G R T E D S T R U C T U R E S I X S E C T O R G R T E S 1 0 0 F T W I D E E R C H

JFlN FEB MRR RPR MRY JUN JLY Fl U G SEP O C T NOV OEC

LRKE CHRMPLRIN STRGE HYDROGRRPH 1968 F C E-2

GRTED S T R U C T U R E SIX S E C T O R GRTES 100 F T W I D E E R C H

J A N FEB M A R A P R M A Y J U N J L Y RUG SEP OCT NOV D E C

o l lFlKE CHRMPLR IN STR-GE HY DROGRRPH 1965 F CE-3 Gfl T E D STRUCTURE S I X SECTOR W I D E

J Fl N FEB MRR FlPR MAY J U N J L Y RUG SEP OCT NO V D E C

o Lf lKE CHf lMPL f l IN STRGE HYDROGRRPH 1971 FCE-3 0

G R T E D S T R U C T U R E S I X S E C T O R G R T E S 1 0 0 F T W I D E E R C H

J A N FEB MFlR Fl P R MAY J U N J L Y RUG SEP O C T NOV DEC

o LRKE CHRMPLRIN STRGE HYDROGRRPH 1968 F C E-3 0

G R T E D S T R U C T U R E S I X S E C T O R G R T E S 1 0 0 F T W I D E E R C H

JRN FEB M F ~ R R P R M F ~ Y JUN J L Y R U G SEP O C T N O V O E C

- 9 L.

\ DURATION ANALYSIS FOR FCE 1 SCIIEME

DISCHARGE

FIG. 41

- 7

L. . -, !~llIWl'I ON ANt\l,YS 1 S I:Pk l:(:li .: S(:l IINI - - - - _ _ STAGE 1'1 SCt!ARGl.

-. - . - -

MRX RNYURL YERR 1937 10 1976 1

fllW RNNURL YEW 1937 10 1976 I

. w ?tRCCWI 07 1 l e t RT OR DCLOY l * 0 1 C l l f O LEVEL

FIG. 42

- - L - 1

I ) [ 11Al<( I

IN RNNURC YLM 1937 ro 1976

FIG. 43

5.6 Cons t ruc t i on Procedure2 -- The gated s t r u c t u r e would be cons t ruc ted i n a dewatered excavat ion p r o t e c t e d by

cof ferdams. I n o r d e r t o handle t h e r i v e r f low, two-stage c o n s t r u c t i o n would be r e q u i r e d w i t h approx imate ly h a l f t h e r i v e r cofferdammed i n each stage. Channel d redg ing would be c o ~ i ~ p l e t e d p r i o r t o c o n s t r u c t i o n except f o r a channel s e c t i o n 695 f e e t l ong which would be r e t a i n e d a t a d i s t a n c e of 2,600 fee t upstreani of t he s t r u c t u r e f o r c o n t r o l l i n g Lake Cha~l ip la in l e v e l s. T h i s would be removed a f t e r conip let ion o f t h e dam. Cons t ruc t i on t i m i n g would be such t h a t t h e s p r i n g f reshe t would be passed between stages and thus h i g h v e l o c i t i e s th rough a c o n s t r i c t e d r i v e r w i d t h cou ld be avoided. The s t r u c t u r e would be founded on t h e dense ti l l overburden which has been determined t o be s a t i s f a c t o r y . A t o t a l o f about 26,000 c u b i c yards of excavat ion would be r e q u i r e d and 16,000 c u b i c ya rds o f concre te .

5 .7 Cost Es t imate

Est imated c a p i t a l c o s t o f a new gated s t r u c t u r e i s $12.3 m i l l i o n f o r e i g h t - f o o t h i g h gates, 12.6 m i l l i o n f o r n i n e f o o t h i g h gates and 12.8 m i l l i o n f o r t e n - f o o t h i g h gates e x c l u s i v e o f channel dredging. D e t a i l e d es t imates a re i n c l u d e d i n Tab le 9. Cost and b e n e f i t s f o r these schemes a r e g i ven i n Table 3.

CONSTRUCTION SCHEDULE GATED STRUCTURE

DESCRIPTION

COFFERDAM STAGE 2

FIG. 44

TABLE 8 SUMMARY OF ESTIMATED COSTS GATED CONTROL STRUCTURE

1. Construction Facilities $ 200,000 m 2. Lands and Damages 50,000 3. Unwatering 728,860 4. Excavation 128,170

I 5. Fill 146,890 6. Concrete (reinforced) 1,794,630 7. Buildings and Utilities 250,000

Sub-total

8. Gates and Stoplogs 9. Contingencies

Total Direct Cost (Items 1 'to 9)

10. Preliminary Studies 11. Engineering and Design



Capital Cost

8 ft. size 9 ft. size 5,455,000 5,605,000

Annual Costs

8 ft. size 9 ft. size

I 1. Interest and Amortization 951,750 967,900 2. Interim Replacement (Gates,

stoplogs, etc. ) 22,840 23,520

I 3. Operation and Maintenance 73,620 75,350 4. Administration and General

Expense 22,090 22,600

Total Annual Cost 1,070,300 1,089,370

10 ft. size 5,755,000 1,358,050

10 ft. size 984,060

T A B L E 9 PETAXLED COST ESTIMATE GATED CONTROL STRUCTURE

I t em Unit Quanti ty Unit P r i c e I t e m Cost Fea ture Cost

1. CONSTRUCTION FACILITIES Mobi l iza t ion , land r e n t a l ,

demobi l iza t ion , e t c . job 1 L.S.

2. LANDS AND DAMAGES l and purchase job 1 L.S.

3 . UNWATERING Cofferdam 1st s t a g e

f i l l , impervious f i l l , rock r i p r a p

Cofferdam 2nd s t a g e f i l l , impervious

I s t e e l s h e e t p i l i n g V 03 f i l l i n c e l l s , Pumping

Cofferdam removal

c. y . 15,400 4.00 ton 2 32 800.00

c.y. 2,950 6.00 j ob 1 L.S. job 1 L.S.

4 . EXCAVATION S t r ipp ing , overburden Excavation, u n c l a s s i f i e d

5. FILL Abutments, common S t r u c t u r e , s e l e c t e d b a c k f i l l Riprap, channel and s lopes F i l t e r , s e l e c t e d granular

6. CONCRETE ( r e in fo rced ) P i e r s Foundation, s l a b S t i l l i n g b a s i n Re ta in ing w a l l s

DETAILED COST ESTIMATE GATEE GudTROL STRUCTURE

I t e m

7. BUILDINGS AND UTILITIES Control, Maintenance

Parking l o t paving

8. GATES AND STOPLOGS Sector ga tes - supply and i n s t a l l Stoplogs - downstream Spillway b r idge Guardrai ls and l i g h t i n g

9. CONTINGENCIES - 15%

I

u TOTAL DIRECT COST

'10. PRELIMINARY STUDIES

11. ENGINEERING ANTI DESIGN SUPERVISION AND ADMINISTRATION

TOTAL CONSTRUCTION COST

12 INTEREST DURING CONSTRUCTION (74%)

CAPITAL COST

Unit Quant i ty Unit P r ice

job 1 L.S.

j ob 6 L.S. job 1 L.S.

s . f . 12,600 50.00 1 i n . f t . 2,000 50.00

Item Cost Feature Cost

8 f t . 10 f t . 8 f t . 10 f t . 4 , ~ O O 4,800,000

SECTION 6 FRYERS ISLAND DAM

6 . 1 Genera l U e s c r i p t i o n

F r y e r s I s l a n d Dam was c o n s t r u c t e d u n d e r t h e 1937 O r d e r o f A p p r o v a l by t h e I J C . It was c o ~ r l p l e t e d i n 1939. The channel e x c a v a t i o n a t t h e S a i n t Jean shoa l was n e v e r comp le ted due t o t h e commencement o f t h e Second Wor ld War and, c o n s e q u e n t l y , t h e dam has n e v e r been used f o r i t s i n t e n d e d purpose .

The dam l o c a t e d a b o u t 4 .7 m i l e s downstream o f Highway 35 b r i d g e has a s i l l a t e l e v a t i o n 83.17 f e e t GSC. It has 31 s l u i c e w a y s , c o n t r o l l e d b y v e r t i c a l g a t e s 30 f e e t w i d e and 12.5 f e e t h i g h . The p i e r s a r e 40 f e e t l o n g and seven f e e t w ide . Each g a t e can be s e t i n f i v e p o s i t i o n s : f u l l y opened, f u l l y c l o s e d , and a t 2, I t and $ f o o t open ings . Two t r a v e l l i n g h o i s t s o p e r a t e t h e g a t e s . A l t h o u g h t h e dam has seen l i m i t e d use, i t has been w e l l m a i n t a i n e d , and t h e g a t e s and o p e r a t i n g m a c h i n e r y a r e i n good c o n d i t i o n . I t i s b e i n g m a i n t a i n e d by t h e Quebec D i v i s i o n o f t h e Depar tment o f I n d i a n and N o r t h e r n A f f a i r s (Canada).

p h o t o g r a p h i s shown i n F i q u r e 45, s e c t i ~ n a l and e l e v a t i o n v iews i n F i g u r e 46.

It i s b e l i e v e d t h a t t h e r e a s o n f o r t h e c o n s t r u c t i o n o f t h e dam a t i t s F r y e r s I s l a n d l o c a t i o n was f o r n a v i g a t i o n purposes i n a d d i t i o n t o c o n t r o l o f l a k e l e v e l s . W i t h t h e d r e d g i n g o f t h e shoa l t o e l e v a t i o n 79 f e e t GSC, as approved i n t h e 1937 Order , a 1 2 - f o o t n a v i g a t i o n d e p t h wou ld be p o s s i b l e a l l t h e way from Lake Champla in t o t h e dam. T h i s w o u l d have e l i m i n a t e d t h e u p p e r s i x - m i l e r e a c h o f t h e Chambly Cana l . It i s p o s s i b l e now t o o p e r a t e t h e danl t o t h e n o n - f l o o d i n g l e v e l o f 89.5 f e e t GSC f o r n a v i g a t i o n improvement up t o t h e f o o t o f t h e S a i n t Jean Rap ids w h i c h wou ld p e r m i t b y p a s s i n g o f t h e Chambly Canal i n t h i s r e a c h . T h i s i s a t p r e s e n t b e i n g a c t i v e l y c o n s i d e r e d and, i n 1970 and 1971, t h e dam was o p e r a t e d t o t e s t g a t e o p e r a t i o n f o r t h i s purpose .

Some improverl ients t o t h e dam wou ld b e r e q u i r e d b e f o r e i t c o u l d be u t i l i z e d as a c o n t r o l s t r u c t u r e . These i n c l u d e new e l e c t r i c s e r v i c e , l i g h t i n g , h e a t i n g equ ipment f o r t h e g a t e s , m i n o r r e p a i r s t o c o n c r e t e , and a new s e r v i c e roadway and s e r v i c e b u i l d i n g . The m a j o r expense f o r t h e scheme, however, wou ld be d y k i n g and d r a i n a g e r e q u i r e d t o p r o t e c t p r o p e r t y when t h e p o o l i s a t t h e h i g h e r l e v e l s r e q u i r e d t o m a i n t a i n Lake Champla in e l e v a - t i o n s .

6.2 R e g u l a t i o n Ana lyses

F r y e r s I s l a n d Dam w o u l d per fo rm i n t h e same way and g i v e t h e same r e s u l t s as a new g a t e d s t r u c t u r e f o r a l l r e g u l a t i o n a l t e r n a t i v e s e x c e p t scheme FCE. Because t h e maximum p o o l l e v e l b e h i n d t h e dam i s l i m i t e d t o e l e v a t i o n 94.0 f e e t GSC ( i n c l u d e s 1 . 6 f e e t o f f r e e b o a r d ) , t h i s s t r u c t u r e does n o t have t h e same c a p a b i l i t y t o m a i n t a i n h i g h ups t ream 1 eve 1 s and ' d m 6 d - ' ~ r r m r e - - -od - C_ -==.2- Ij

A r e g u l a t i o n r u n (FCE-4) was made t o d e m o n s t r a t e t h e maximum per fo rmance t h a t can b e o b t a i n e d w i t h a poo l o f 94 .0 f e e t GSC. An a l t e r n a t i v e c o m p u t a t i o n was a l s o made w i t h no f r e e b o a r d on t h e g a t e s , i . e . , w i t h a p o o l o f 9 5 . 5 f e e t GSC b e h i n d t h e dam.

R a t i n g c u r v e s showing t h e s t r u c t u r e ' s per formance a r e p r o v i d e d i n F i g u r e 47.

6 . 3 Impac t o f F r y e r s I s l a n d Dam on Upstream L e v e l s

Scheme FCE-4 w i l l g i v e t h e r e q u i r e d d u r a t i o n p e r i o d s a t a maximum l e v e l o f 97.5 f e e t USGS f o r an average o f one o u t o f t h r e e y e a r s . S a c r i f i c i n g f r e e b o a r d on t h e s t r u c t u r e w i l l o n l y improve t h i s l e v e l t o 97 .7 f e e t USGS. T y p i c a l hydrographs and d u r a t i o n c u r v e s f o r scheme FCE-4 a r e shown i n F i g u r e s 51 t o 54.

FRYERS I S L A N D DAM

Upstream View

FIG. 45 Downstream View

-GATE TROLLEY

SPREADER BEAM

WEST ABUTMENT

FRYERS ISLAND TOP OF PIER 100;17'

EMERGENCY GAIN WORKING GAIN

82.67' SlLL BEAMS GROUND LINE

CONCRETE APRON

LlNE - - - - - -

ROCK ----- SECTION A-A

GATE TROLLEY

-CONTROL ROOM

EL. 100.17- ORIGINAL GROUND

--- EL. 77.17-

-.- A --- --- ---_ - - ----__ ----__ -----'- _ ______- - - - -

\LINE OF CUT OFF WALL

NOTEZALL ELEVATIONS G.S.C. DATUM FOR U.S. DATUM ADD 0.37'

ELEVATION VIEW

EL. 100.17- - I I TOP OF GATES 95.67<

I

GATE SlLL E~.83.17' -Ap- - -----

EL. 77.17-

- GROUND

LlNE

LlNE

SCALE ALL VIEWS 1 RlCHELlEU RIVER REGULATORY WORKS I I FRYERS ISLAND DAM 1 PLAN, ELEVATlON,AND SECTION

PHYSICAL ASPECTS COMMITTEE FIG. 46 I

LAKE CHAMPLAIN STAGE-DISCHAROE RELATIONSHIP

FRYER S ISLAND DAM OPERATION

FRYERS ISLAND DAM GATES OPERATED TO 0- -/ MAINTAIN POOL LEVEL AT EL. 94.0 AND ST. JEAN SHOAL DREDGED 0

DISCHARGE IN C.F.S. x 1000

6.4 Dyking and Drainage Works-

6 . 4 .1 Need f o r Dykes and Drainage Works

Uur inq f l o o d f l ow c o n d i t i o n s , t he qates i n t he danl w i l l be open so t h a t t he do., ~ r c l t j

~ . e d u c t i o n s i n upstreal11 water l e v e l s can be a t t a i n e d . I n t h e reach between F rye rs I s l a n d Ddlil and t h e r a p i d s a t S a i n t Jean, t he r i v e r w i l l g e n e r a l l y be he ld w i t h i n i t s banks and dra inage can be accornplished by g r a v i t y . However, r e g u l a t i o n schemes r e q u i r i n g the management o f non - f l ood p e r i o d water l e v e l s n e c e s s i t a t e t h e p a r t i a l c l o s i n g o f ga tes so as t o a t t a i n p r e s c r i b e d upstream l e v e l s a t Lake Champlain by c r e a t i n g a backwater poo l . The e x t e n t t o wh ich t h e l a k e l e v e l s a r e t o be managed, as w e l l as t h e d u r a t i o n s necessary, would depend on t h e se lec ted r e g u l a t i o n p lan . However, a l l management schemes have i n common t h e requ i rement t h a t t h e l e v e l s n o t f a l l below a c e r t a i n minimum throughout t h e yea r .

To h o l d Lake Champlain l e v e l s between e l e v a t i o n s 94.0 f e e t USGS and 95.0 fee t USGS (expected range o f o p e r a t i o n ) would r e q u i r e t h a t t h e pool a t F rye rs I s l a n d Dam be main- t a i n e d app rox ima te l y a t e l e v a t i o n 94.0 f e e t GSC d u r i n g v a r i o u s t imes o f t h e year . Since t h e R i c h e l i e u R i v e r bank l e v e l s and ad jacen t topography a r e below 94.0 f e e t GSC i n many p laces, i t would be necessary t o p r o v i d e dykes a long the r i v e r t o p r o t e c t these l o w l y i n g areas f rom inunda t i on . The re fo re a system of dykes and w a l l s connect ing t o h i g h ground would be necessary. Also, s i n c e ove r l and runof f f rom l o c a l p r e c i p i t a t i o n w i l l be prevented from d r a i n i n g i n t o t h e r i v e r a t those t imes when h i g h pool l e v e l s a r e main ta ined, i t would be necessary t o p r o v i d e f a c i l i t i e s t o e i t h e r pump t h e r u n o f f over t he dykes, o r t o s t o r e i t i n ponding areas.

6.4.2 Drainage C r i t e r i a

Runof f d r a i n i n g t o t h e r i v e r under h i g h pool c o n d i t i o n s i s assessed i n terms o f the g r a v i t y c r i t e r i a , i . e . , whether t he upland water l e v e l i n t h e d i t c h e s and p ipes i s h ighe r t han t h e pool l e v e l s i n t h e r i v e r ( g r a v i t y c o n d i t i o n ) o r l ower ( n o n - g r a v i t y c o n d i t i o n ) . For g r a v i t y c o n d i t i o n s , t h e system i s designed t o accommodate the 10-year f requency r a i n - f a l l ; f o r n o n - g r a v i t y c o n d i t i o n s , t h e system i s designed f o r t h e 25-year f requency r a i n f a l l . The s e l e c t i o n o f these f requenc ies f o l l o w s genera l p r a c t i c e i n Canada.

I f g r a v i t y c o n d i t i o n s e x i s t , r u n o f f i s i n t roduced d i r e c t l y i n t o t h e channel f rom d i t c h e s o r storm water p ipes d r a i n i n g i n t o p i p e o u t l e t s . Where poss ib le , h i g h l e v e l d i t c h e s hav ing e leva ted s ides have been used f o r d ra inage t o t h e p i p e o u t l e t s so as t o r a i s e low water l e v e l s s u f f i c i e n t t o ga in g r a v i t y f l o w s .

I f g r a v i t y d i scha rge c o n d i t i o n s a r e n o t ava i l ab1 e, ponding areas a r e employed where p o s s i b l e . These ponds a r e designed t o c o n t a i n as much o f t h e r u n o f f as i s p r a c t i c a b l e w i t h i n e x i s t i n g l ow l y i n g areas and w i t h o u t t h e c o s t l y purchase o f ad jacen t p r o p e r t i e s . Runof f q u a n t i t i e s i n excess o f t h e volumes con ta ined i n t h e ponding areas a r e pumped t o t h e e x t e n t necessary t o prevent t h e f l o o d i n g o f i n t e r i o r lands. Each o u t l e t t o t h e r i v e r f rom the n o n - g r a v i t y systems would be prov ided w i t h a f l a p g a t e and emergency s l u i c e ga te t o p reven t back f low f rom t h e r i v e r .

6.4.3 Dykes and Wal ls

To t h e e x t e n t poss ib le , t h e p r o t e c t i v e works would be accomplished u s i n g e a r t h f i l l sec t i ons a long t h e r i v e r bank. Where l a t e r a l space i s l i m i t e d due t o t h e presence o f e x i s t i n g s t r u c t u r e s , concre te f l o o d w a l l s would be used t o extend t h e l i n e o f p r o t e c t i o n . The dykes would be cons t ruc ted of dredged impervious m a t e r i a l r a i s e d t o l e v e l s 1.5 f e e t above t h e maximum pool su r face i n t h e r i v e r . I nc luded i n t h e 1.5 f ee t o f f r eeboa rd w i l l be a 1 2 - f o o t wide g rave l road s u r f a c i n g on t h e t o p o f t h e dyke. I n o r d e r t o p r o t e c t t h e exposed s i d e o f t h e dyke f rom eros ion, a 12- inch t h i c k b l a n k e t o f r i p r a p i s s p e c i f i e d . Dyke s i d e s lopes would be one f o o t v e r t i c a l t o two f e e t h o r i z o n t a l w i t h t h e p ro tec ted s i d e o f t h e dyke seeded w i t h a grass cover ( F i g u r e 50) .

The w a l l s a r e o f t h e f l o o d w a l l t y p e designed t o c o n t a i n t h e maximum pool l e v e l w i t h 1.5 f e e t f reeboard . The c a n t i l e v e r shape serves t o r e s i s t o v e r t u r n i n g f o r c e s due t u t h e h i g h pool l e v e l . The w a l l would be composed o f r e i n f o r c e d conc re te m o n o l i t h sec t i ons ( F i g u r e 50).

Walls and dykes a r e r e q u i r e d along bo th banks o f t h e r i v e r i n t he reach between I t.yclt.s I s l a n d Daln and t h e r a p i d s a t S a i n t Jean (F igu re 43). On t h e l e f t bank, t h e d y k ~ ~ ~ t . o t c ~ t ing I l e Ste-Therese i s extended across t h e i n te rconnec t i ng channels t o I l e Ste-M,rr 1 1 .

, ~ n d t o t h e mainland. Th i s arrangement i s se lec ted t o avo id t h e necess i t y f o r c o n s t r u ~ t l r ~ c j cx tens i ve dykes around both island., r e q u i r i n g t h e removal o f e x i s t i n g s t r u c t u r e s and p o s s i b l y l o s s of t h e use of I l e Ste-Marie. The l e f t bank would be p ro tec ted by 1,300 f e e t o f f l o o d * w a l l and 13,800 f e e t o f dykes. Along t h e r i g h t bank, t h e p r o t e c t i v e works would i n c l u d e 7,000 f e e t of f l o o d w a l l and 25,000 f e e t o f dykes.

6.4.4 Drainage Systems

The dra inage systems a r e separated by topograph ic requirements i n t o f o u r p r i n c i p a l areas and f i v e minor areas (F igu re 49). The purpose o f each system i s t o ensure t h a t r u n o f f t o t h e dykes and w a l l s can d ischarge i n t o t h e r i v e r when l e v e l s pe rm i t , o r be e i t h e r s to red i n ponding areas o r pumped i n t o t h e r i v e r when pool l e v e l s a re too h i g h f o r g r a v i t y d ischarge.

The a v a i l a b l e s torage i n Ponding Areas 1 and 3 i s 2.0 and 4.0 a c r e - f e e t r e s p e c t i v e l y and i n Area 2 i s 0.4 ac re - foo t . These c a p a c i t i e s a re augmented by pump s t a t i o n s having 20 c f s c a p a c i t y a t Area 1, 70 c f s c a p a c i t y a t Area 2, and 24 c f s c a p a c i t y a t Area 3. These systems a r e designed t o handle t h e 25-year frequency r u n o f f c o i n c i d e n t w i t h h i g h pool l e v e l s i n t h e r i v e r . Drainage i s accomplished v i a d i t c h e s and c u l v e r t s o r storm water p ipe systems lead ing t o p i p e o u t l e t s .

Area 4 con ta ins an e x i s t i n g body o f water of approx imate ly 40 acres p r e s e n t l y connected t o t h e r i v e r and r e f l e c t i n g r i v e r water l e v e l s . With t h e enc los ing dykes, t h i s body o f water can be main ta ined a t n a t u r a l l e v e l s by p e r m i t t i n g i t t o f l u c t u a t e w i t h t h e r i v e r through in te rconnec t i ng p ipes w i t h c l o s u r e gates. However, i t would be necessary t o p rov ide a pump s t a t i o n t o ensure t h a t t h e pond l e v e l s can be drawn down when requ i red . T h i s pump s t a t i o n would need a 12 c f s capac i t y . Drainage i n Area 4 would be d i r e c t e d t o t h e pond.

I n a d d i t i o n t o t h e above, two pump s t a t i o n s o f 5 c f s c a p a c i t y each would be needed near two minor t r i b u t a r i e s on t h e bank: I n o t h e r areas where ex te rna l dra inage f a c i l i t i e s a r e n o t necessary, sump pump f a c i l i t i e s would be prov ided f o r each s t r u c t u r e a f fec ted . These pumps would d ischarge any seepage from h i g h pool l e v e l s .

The dra inage works t o t a l approx imate ly 54,000 f e e t o f d i t ches , 24 p ipe o u t l e t s ( 24- inch t o 48- inch d iameter ) , 76 c u l v e r t s (24- inch t o 42- inch d iameter ) , 6,700 f e e t of storm water p i p i n g (18- inch t o 30- inch d iameter ) , 21 i n l e t s , 30 manholes, 25 sump pumps, and s i x pump s t a t i o n s . Misce l laneous works i n c l u d e headwalls, f l a p gates, s l u i c e gates,

I and r i p r a p .

6.5 Cons t ruc t i on Procedures 1

No d i f f i c u l t i e s would be exper ienced i n schedu l ing t h e dyke and dra inage const ruc- t i o n . However, t h e r e q u i r e d dykes and dra inage would have t o be cons t ruc ted p r i o r t o t h e channel dredging i n o r d e r t o ma in ta in c o n t r o l o f upstream l e v e l s .

I 6.6 C o s t E s t i m a t e s

Est imates o f c o s t t o u t i l i z e Fryers I s l a n d Dam as a c o n t r o l s t r u c t u r e r e f l e c t improvements r e q u i r e d t o p u t i t i n t o good opera t i ng c o n d i t i o n s as w e l l as t h e c o s t of dyk ing and dra inage works. T h i s i s es t imated a t $9.9 m i l l i o n . Tab le 10 p rov ides a summary

I o f cos ts and Tab le 11 d e t a i l e d es t imates . I

I' RIPRAP ON 6" GRAVEL BEDDING 7

COMPACTED

EMBANKMENT

"'GRAVEL ROAD SURFACING

RIVER

L O W W L 8 9 5

I F T BED STRIPPING I .?,... - .

f I I

4 " GRAVEL

-1 2, k

TYPICAL DYKE SECTION - TOE DRAIN

6 " GRAVEL SURFACE ON RAMP

M A X W L 9 4 . 0

N.G.L.

\ i18" DIA CONCRETE

CULVERT

DYKE SECTION AT BOAT RAMP -

/ GRANULAR BACKFILL

RIVER

M A X W L 9 5 0 1 7 4 8' HlGH RETAINING WALL

I ' I / r TOPSOIL SEEDING L O W W L B 9 5 1 I 'I i

+ loq'+ EL 9 6 5 >

EL9050 , 1 ' 1 / / r EXISTING MASONARY WALL T ? 1 1 1 / rTOPSOIL SEEDING

M A X W L 9 5 0

f T

' , , I / / /

NGL. EL 8 7 5

MANHOLE Z c o N c w T E PIPE

-

TYPICAL RETAINING WALL SECTIONS 0 1 2 3 4 5 6 -

10' HlGH RETAINING WALL

GRANULAR BACKFILL

~ ~ " D I A CONCRETE PIPE 2

30" DlA FLUSH BOTTOM SLUICE GATE ARRANGEMENT

EL 9 7 5 7 -

TOPSOIL SEEDING

34': DlA FLAP GATE

6''

NGL OUTLET FROM TOE

DYKE SECTION AT LOW LEVEL 0

I , , I ( I DROP INLET /

/c 3' 4 7 I' FREEBOARD 1 - 3 ' 4

I I / /

/ L O W W L 8 9 5 I /' _ - - ---- I - - - -- 0 a

I.:-- - - - - & .,- 30" DIA CONCRETE PIPE 1 > b A A "

DISCHARGE :30 CFS

-4 3' It

J r EL 9 0 0

r E L 8 9 0

DRAINAGE DITCH X-SECTION

I . a \ EL 8 9 0

HlGH LEVEL OUTLET FOR GRAVITY DRAINAGE 4 1 ' ~ 3 5 ' 4 VL

I N T E R N A T I O N A L C H A M P L A I N - R I C H E L I E U B O A R D I r R I C H E L I E U R I V E R R E Q U L A T O R Y W O R K S I 0 1 2 3 4 5 6 7 8 F T

HORIZONTAL - I FRYERS ISLAND DAM SCHEME DYKING AND DRAINAGE WORKS I

0 1 2 3 4 F T VERTICAL - 1- 19 -4 I* +- em -1 [OF NOTE : ELEVATIONS TO G SC DATUM

I' RIPRAP ON 6" GRAVEL BEDDING FOR U.S. DATUM ADD 0.37 F E E T SCALES FOR DYKE SECTIONS AND DRAINAGE DIICH

TYPICAL SECTIONS

P H Y S I C A L A S P E C T S

C O M M I T T E E F I G . 50

o LFEKE CHAMPLAIN STRGE HYDROGRRPH 1965 0

FCE-4

m F R Y E R S I S L R N D DRM S T - J E R N S H O R L D R E D G E D

J A N FEB MAR APR M A Y J U N JLY R U G SEP O C T ' NOV OEC

J A N FEB M A R Fl P R MFlY J U N . JLY FlUG SEP OCT NOV - DEC

o LAKE CHRMPLRIN STAGE HYDROGRRPH 1968 FCE-4 0

F R Y E R S I S L R N D DRM S T . J E R N S H O R L D R E D G E D

J A N FEE MFlR FlPR MAY J U N JLY RUG S E P OCT NOV OEC

--. \ L-

\ 111IRAT LON AT;AI,YS IS FOI? 1:C:li 4 ZCIIEME

r- ----- MX m u m . rrm 1917 T O 1376

? l 1

nln RNnURL V C M I I S 7 10 1878 I

FIG. 54

FIG. 55

TABLE 10

SUMMARY OF ESTIMATED COSTS DYKING AND DRAINAGE WORKS FRYERS ISLAND DAM PROPOSAL

1. Construction Facilities 2. Lands and Damages 3. Dykes and Retaining Walls 4. Drainage 5. Fryers Island Dam Renovations 6. Contingencies

Total Direct Cost

7. Preliminary Studies 8. Engineering and Design

Supervision and Administration



Capital Cost

Annual Costs

Interest and Amortization (78% rate - 50 year period) 762,480

Interim Replacement 13,640 Operation and Maintenance 202,380 Administration and General Expense 60,700

Total Annual Cost 1,039,200

TABLE 11

DETAILED COST ESTIMATE DYKING AND DRAINAGE WORKS FRYERS ISLAND DAM PROPOSAL

Item Unit Quantity Unit Price Feature Cost

200, GO0

Item Cost

CONSTRUCTION FACILITIES Mobilization, land rental, demobilization, etc. job 1 L. S.

LANDS AND DAMAGES Urban land purchases sq. ft. 1,200,000 1.00

acre 10 1,000.00 Agricultural land purchases Contingencies - 40% of land purchases Land clearing Relocation of buildings

acre each

DYKES AND RETAINING WALLS Dykes : Embankment - hauling and placement Foundation stripping Riprap - riverside slope Riprap bedding Toe drain gravel Gravel - road surfacing Boat access ramps Low level outlets with flap and Emergency gates - 42" pipe size

- 30" pipe size - 24" pipe size

Top soil and seeding

cu. yd. cu. yd. cu. yd. cu. yd. cu. yd. cu. yd. each

each each each acre

Retaining walls: Concrete - supply, form and place Reinforcement Foundation excavation Backfill - granular

cu. yd. lb .

cu. yd. cu. yd.

- DETAILED COST ESTIMATE DYKING AND DRAINAGE WORKS FRYERS ISLAND DAM PROPOSAL

Unit Quantity Unit Price Item Cost Feature Cost Item

4. DRAINAGE High level gravity drainage: Ditch excavation Fill

V High level outlets Farm road culverts Drainage inlets

cu. yd. 11,000 cu. yd. 10,000 each 8 each 7 each 2 1

Low level drainage: Ditch excavation Fill Storm Sewers - installed

- 18" concrete pipe - 24" concrete pipe - 30" concrete pipe

Manholes Pumping stations Controlled outlets -5ponding areas Sump pump units C.M. pipe culverts - Highway 21 Driveway culverts - modifications Ditch crossings - natural creeks

cu. yd. 15 ,.OOO cu. yd. 11,000

lin. ft. lin. ft. lin. ft. each job each each each each each

5. FRYERS ISLAND DAM RENOVATIONS Building Electric Lights Repairs and Modifications Minor mechanical renovations for foot bridge

Miscellaneous

L. S. L.. S. L. S.

job

DETAILED COST ESTIMATE DYKING AND DRAINAGE WORKS

FRYERS I S L A N D DAM PROPOSAL

I t e m U n i t Q u a n t i t y

6 . CONTINGENCIES D y k i n g and D r a i n a g e - 1 5 % on $6,625,430 Frye r s Island D a m - 2 0 % on $250,000

TOTAL D I R E C T COST I

7 . PRELIMINAKY S T U D I E S 1 8. E N G I N E E R I N G AND D E S I G N - ' S U P E R V I S I O N AND ADMINISTRATION

TOTAL CONSTRUCTION COST I

9. I N T E R E S T DURING'CONSTRUCTION - 7$%

C A P I T A L COST

U n i t P r i c e I t e m C o s t F e a t u r e C o s t

SCCTION 7 LAKE LEVEL TREND STUDIES

7.1 General

There i s ev idence t h a t t h e surface l e v e l o f Lake Champlain has been r i s i n g f o r a number o f years . Var ious researchers have produced analyses t o demonstrate t h a t t h e annual peak stages, t h e annual l ow stages and r a t i n g cu rve o f l a k e stage a t Rouses P o i n t versus R i c h e l i e u R i v e r f l o w a t F rye rs Rapids have been moving upward.

The s i g n i f i c a n c e of such t rends t o t h e ICRB i s t w o - f o l d : 1 ) I n t h e absence o f any phys i ca l works, t h e Board must be concerned w i t h f u t u r e c o n d i t i o n s o f l a k e stage and t h e i r p o s s i b l e impact ; and 2 ) if phys i ca l works a r e proposed, c o n s i d e r a t i o n shou ld be g i ven t o t h e a b i l i t y o f t h e s t r u c t u r e t o n e u t r a l i z e and i n f l u e n c e t h e t rends.

I n o r d e r t o determine t h e e x t e n t t o which t r e n d i n g i s t a k i n g p l a c e and what t h e sources of such t r e n d i n g m igh t be, severa l avenues of i n v e s t i g a t i o n were f o l l o w e d . These a r e desc r i bed be1 ow.

7.2 Evidence o f Lake Leve l Trends

I n i t i a l l y , analyses of t r ends of t h e l a k e l e v e l s themselves were undertaken. The h i g h e s t and l owes t mean d a i l y l e v e l s f o r each yea r o f t h e p e r i o d o f r e c o r d 1875 th rough 1976 were t a b u l a t e d . For t h e maximum l e v e l s , t h e data were accumulated by 12-month p e r i o d s beg inn ing October 1 and f o r t h e minimums, s t a r t i n g A p r i l . L i n e a r t r e n d analyses o f t h e whole r e c o r d and segments of t h e r e c o r d were performed. These r e s u l t s a r e t a b u l a t e d i n Tables 12 and 13. As can be seen f rom t h e t a b l e s , t h e degree and d i r e c t i o n o f t r e n d i s dependent on t h e p e r i o d o f r e c o r d se lec ted . For t h e maximum l e v e l s and f o r t h e e n t i r e p e r i o d o f reco rd , an upward t r e n d o f n e a r l y one -ha l f a f o o t i n 100 yea rs was noted. However, when t h e r e c o r d i s analyzed i n two p o r t i o n s , an upward t r e n d o f n e a r l y two f e e t i n 100 yea rs occurs i n t h e f i r s t h a l f of t h e r e c o r d and a downward t r e n d of .04 o f a f o o t i n 100 yea rs occurs i n t h e second h a l f . F u r t h e r segmenting o f t h e r e c o r d r e s u l t s i n g r e a t e r v a r i a t i o n s i n r a t e and d i r e c t i o n o f apparent t rends. '

The a n a l y s i s o f a minimum d a i l y t r ends a l s o show t h a t t he d i r e c t i o n and degree o f t r e n d i n g i s a f u n c t i o n of t h e segmenting o f t h e p e r i o d o f r e c o r d a l t hough t h e l a t t e r p a r t o f t h e r e c o r d shows an upward t r e n d i n every i ns tance .

Annual r a t i n g curves were developed i n t h e r e g u l a t i o n analyses by p l o t t i n g mean d a i l y l a k e l e v e l s a t Rouses P o i n t a g a i n s t mean d a i l y d ischarges a t F rye rs Rapids f o r i c e f r e e p e r i o d s o f t h e yea r . Ra t i ng curves were then f i t t e d th rough t h e s c a t t e r o f p o i n t s i n o r d e r t o rep resen t t h e r e l a t i o n o f l a k e l e v e l t o r i v e r f l o w f o r t h a t p a r t i c u l a r yea r . These ana lyses were done o n l y f o r t h e p e r i o d 1938 th rough 1976 because o f t h e l a c k o f r e l i a b l e data p r i o r t o t h a t t ime . Tab le 14 l i s t s some o f t h e i n f o r m a t i o n a v a i l a b l e f rom these r a t i n g curves showing how changes i n l a k e l e v e l needed t o p r o v i d e g i v e n f l o w s i n t he R i c h e l i e u R i v e r have changed over t h e years . Also, a mathemat ical a n a l y s i s was undertaken o f t r ends i n t h e l a k e s t a a e - r i v e r f l o w relations hi^. and c o n s i s t e n t w i t h t h e t a b u l a t e d

The t r e n d i n g o f l a k e l e v e l s and o f l a k e o u t l e t d ischarge r e l a t i o n s h i p s can be due t o severa l causes. The p o t e n t i a l sources i n c l u d e data a n a l y s i s , c r u s t a l movement, sed i - menta t ion , t h e widening o f t h e Chambly Canal, g rowth o f a q u a t i c v e g e t a t i o n i n t h e 3

T a b l e 12 Trend A n a l y s i s

Annual Maximum Mean D a i l y L e v e l s

P e r i o d of Record 1875-1976

S l o p e P e r i o d P e r i o d P e r i o d o f A n a l y s i s Mean ( ~ t l l o o Y r s . ) o f A n a l y s i s Mean S lope of A n a l y s i s Mean S lope

Year 1 - Year 1 0 98.70 - 8 .10

NOTES

Trend e q u a t i o n f i t t e d by l e a s t s q u a r e s a n a l y s i s '

Lake L e v e l = c o n s t a n t + S l o p e X Year \

Maximum Mean D a i l y Leve l s s e l e c t e d by Water Year (Oc t . ' . l -Sep t . 30)

Table 13 T r e n d A n a l y s i s

Annual' Minimum Ekan D a i l y L e v e l s

P e r i o d of Record 1871-1974

r S l o p e P e r i o d P e r i o d of A n a l y s i s Mean (Ft /100 YrsL --- of A n a l y s i s M s S l o p e

Year 1 - Year 1 0 93 .82 -10.7

11 - 2 0 93.82 1 6 . 1

NOTES

Trend e q u a t i o n f i t t e d by l e a s t s q u a r e s a n a l y s f a Lake L e v e l = Cons tan t -I- Slope X Year

Minimum Mean D a i l y L e v e l s s e l e c t e d by C l i m a t i c Yeer ( ~ p r i l l -March 31)

P e r i o d of A n a l y s i s Mean S lope - -

Table 14 Rating Curve Chan~es

Lake Levels Associated With Richelieu River Flows

5,000 cfs .10,000 cfs

95.0 95.2 95.5 95.3 95.2 95.2 95.5 95.5 95.5 96.4 95.5 95.5 95.2 95.2 95.4 95.8 95 - 5 95.6 95.4 95.6 95.5 95.4 95.5 95.5 96.0 95.6 95.8 95.9 95.4 95.5 95.8 96.1 96.2 95.9 . 96 .1 96.0 96.3 95.9 95.8 '

96.0

20,000 cfs

97.0 96.8 97.4 97.2 97.15 97.4 97.4 97.5 97.5 37.4 97.55 97.4 97.4 97.4 97.4 97.6 97.4 97.4 97.5 97.5 - -

' 97.1 97.1 97.4 97.2 97.4 97 - 6 97.2 - - 97.4 97.6 97.4 97.6 97 - 5 97.7 98.0 98.4 97.6 97 .O 97.8

30,000 cfs

IY,,E 10 X 10 TO THE INCH. 7 X 10 INCHES n- c KEUFFEL ESSER CO. MADE IN U S A.

RICHELIEU R I V E R DISCHARGE (1000 x C F S )

Ricllelieu River, changes in the regional climate. and dynamic routing e f f ec t s not included in the hydraulic ana lys i s .

Data analysis can produce apparent trends i f the basic lake stage or r i ve r discharge data i s not analyzed in a consis tent manner or i f changes in datuni take place which a re not accounted fo r in subsequent trend ana lys i s .

Crustal movement, whether i t be due t o g lac ia l rebound o r other o r ig in s , can produce trends only i f the point where lake leve ls a r e being monitored i s moving d i f fe ren- t i a l l y with the o u t l e t "control" . Depending on the d i rec t ion of 'such a t ipping, an apparent upward o r downward trend would appear in the records.

Sedimentation has been suggested as a source of lake trending. If sedimentation in the Richelieu River i s taking place in a way t h a t reduces the hydraulic e f f ic iency of the channel, the s tage discharge curve would be ra i sed . The reduction in discharge eff ic iency would a l so be re f lec ted in the trend ana lys i s , espec ia l ly a t low lake l eve l s .

The widening of the Chambly Canal in the ear ly 1970'-s has been suggested as a source of change in the s tage discharge relat ionship in the lake. Because of the canal - encroachment removal of cross-sectional areas coul'd cons t r i c t flow and lead t o generally higher lake s tages . This would be a one-time occurrence, however, and would not contr ibute t o a continuing t rend.

The growth of aquat ic vegetation in denser stands over recent years has been suggested a s a source of trending in the lake in the s tage discharge curve. Since such growth would reduce hydraulic eff ic iency and, i f su f f i c i en t l y thick, could e f f ec t i ve ly remove cross-sect ional area par t icu la r ly fo r slower ve loc i t i e s , the impact could be f e l t on the lake l eve l s .

Changes in regional climate could a f f ec t lake s tage t rends, par t icu la r ly mean and low level s tages , but would not a f f e c t the s tage discharge re la t ionsh ip . If a period of higher prec ip i ta t ion i s taking place, then higher mean and low lake s tages will tend t o r e su l t . The character of spring runoff in terms of amount of snowpack, r a t e of snowmelt, e t c . , would a f f e c t the annual peak stages but the to ta l annual p rec ip i ta t ion woXl3 not -

necessar i ly do so.

Final ly , most of the invest igat ions of stage-discharge relat ionships deal -with the lake- r iver system as a steady s t a t e niodel . Dynamic flow e f f e c t s could be the source of s h i f t s in ra t ing curves but not of long-term trends.

7 .4 Invest igat ion of Possible Causes

A var ie ty of invest igat ions were undertaken to determine the ro le of each of the possible causes of trending mentioned in the above sect ion.

7.4.1 Data Analysis

The gauge records fo r the lake and the r i ve r were re-examined t o determine t h e i r r e l i a b i l i t y and i t was determined t h a t , general ly , the basic data was good f o r the period of time when systematic records were obtained ( s ince 1938). A potential problem was noted in the ana lys i s of lake s tages i f the e n t i r e 100+ year record i s used. In 1938, the re la t ionsh ip of the lake s tage datum to mean sea level was adjusted t o .50 f e e t . Prior t o t h a t time, a l l lake s tages a t Rouses Point-were referred t o an elevat ion of 92.50 f e e t USGS above sea l eve l . After 1938, the datum was referenced a t 93.00 f e e t USGS above sea leve l . Thus, in analyzing the trend of lake s tages , care must be taken t o add the lake gauge reading to the current datum elevat ion. If a l l gauge readings a r e added t o the datum in e f f e c t a t the time, then the f i r s t two-thirds of the period of record will be plotted one- half foo t lower than i t should. This would lead t o an apparent upward trend in an analysis of lake s tages.

7.4.2 Crustal Movement

Crustal movement will produce lake s tage trending a t Rouses Point only i f i t

r e s u l t s i n r e l a t i v e v e r t i c a l l l l o t i o n between Rouse\ i ' o i n t and t h e R i c l i e l i e u I t i v r r . T h e r r i s c o r i f l i c t i n q c v ~ d c n c e as t o t h e ~llovc>alent o f Rn11sc.1, [ ' o i r ~ t i n r c l a t i o n t o o t h c r IIOII~L[, ~III

t h e l a k ~ - R u r l l n r l i on, f o r i n s tancrl . qolllc a n a l y s o z o f wlit(>l- l e v e l ( f a t a l t cn r i t o clct~~ot~,. l t , I l ( b

t h a t Rouses Po i t i t i s l i lov inq up w i t h I - c l a t i o n t o lIu1-1 I nclton, w h i l e o t h e r d a t a d f ~ v e l o l ) c ~ l l I,y l s a c h s e n f rom h d s e l i n c l e v e l 1 i n q w o u l d i n d i c a t e t h e r e v e r s e . However, o f i n t e r e s t t~('rrb I< ,

t h e absence o f e v i d e n c e t h a t Rouses P o i n t i s mavin!! v e r t i c a l l y i n r e l a t i o n t o S a i n t JPCI~I. Thus, i t i s b e l i e v e d t h a t c r u s t a l nioven~ent does n o t c o n t r i b u t e t o t h e t r e n d i n g o f l a k e s t a g e s o r t h e s t a g e - d i s c h a r g e c u r v e a t Rouses P o i n t .

X 7.4.3 S e d i m e n t a t i o n

The i m p a c t o f s e d i m e n t a t i o n o f l a k e s t a g e t r e n d i n g and s t a g e d i s c h a r g e r e l a t i o n s h i p changes was i n v e s t i g a t e d i n s e v e r a l ways. W i t h t o p o s s i b l e s e d i m e n t a t i o n i n t h e R i c h e l i e u R i v e r , i t i s u n l i k e l y t h a t s e d i m e n t a t i o n i n t h e c o n t r o l s e c t i o n a t S a i n t Jean Rapids w o u l d t a k e p l a c e s i n c e i t i s an a r e a o f a c c e l e r a t e d f l o w and any sed iment i n t h e r i v e r w a t e r a t t h a t p o i n t w o u l d t e n d t o b e c a r r i e d downstream. T h e r e i s some e v i d e n c e

R i c h e l i e u R i v e r d e p o s i t sedimen a t t h e i r mouth. t h a t s e d i m e n t a t i o n t a k e s p l a c e p s t r e a m o f t h e c o n t r o l s e c t i o n where t r i b u t a r i e s i n t o t h e

0

To d e t e r m i n e t h e p o s s i b l e i m p a c t o f s e d i m e n t a t i ~ n i n t h e r i v e r s h o u l d i t t a k e p l a c e ,

- Backwate r r u n s were a l s o made u s i n g c r o s s - s e c t i o n s deve loped f r o n i sound ings o f t h e R i c h e l i e u R i v e r t a k e n i n 1977 w i t h t h e c a n a l w i d t h a t pre-1970 condition,^ and compared w i t h r u n s u s i n 4 1912 and 1938 d a t a . No d e t e c t a b l e l a k e r i s e was f o u n d f o r a range o f f l o w s f r o m 10,000 to440,000 c f s . Thus, ~ e . i . s - n . ~ & i ~ d e n n t a t i o n has any app=c?a- ----.

h l e e f f e c t on l a k e l e v e l ?

F i n a l l y a sed iment s u r v e y was u n d e r t a k e n by u s i n g a c o m b i n a t i o n o f s o n a r and p h y s i - c a l samp l ing . However, t h e e f f o r t was u n s u c c e s s f u l s i n c e weed g r o w t h p r o v e d t o b e so t h i c k t h a t t h e s o n a r c o u l d n o t a d e q u a t e l y show t h e s o f t , u n c o n s o l i d a t e d d e p o s i t s on t h e r i v e r bo t tom.

7.4.4 Canal W i d e n i n g

The i m p a c t o f c a n a l w i d e n i n g on t h e s t a g e - d i s c h a r g e r e l a t i o n s h i p was i n v e s t i g a t e d i n two ways: i n t h e p h y s i c a l model, and i n a b a c k w a t e r a n a l y s i s p e r f o r m e d m a t h e m a t i c a l l y .

The P h y s i c a l model s t u d i e s o f t h e p roposed w e i r and g a t e d s t r u c t u r e t e s t s were u n d e r t a k e n a t t h e L a S d l l e H y d r a u l i c L a b o r a t o r y t o d e t e r m i n e t h e changes i n ups t ream w a t e r l e v e l s r e s u l t i n g f r o m t h e 1970-72 w i d e n i n q o f t h e Chanibly Canal a t S a i n t Jean. These e x p e r i m e n t s e s t a b l i s h e d t h a t t h e i n c r e a s e o f r i v e r s t a g e i m m e d i a t e l y ups t ream o f t h e c a n a l works was m i n o r , r a n g i n g f r o m 0.04 f o o t f o r a d i s c h a r g e o f 27,000 c f s t o 0 .21 f o o t f o r a

IC-

O f f i c e s t u d i e s u s i n g a m a t h e m a t i c a l model o f t h e r i v e r were t h e n employed t o check o f t h e p h y s i c a l m o d e l ' s r e s u l t s as w e l l as t o d e t e r m i n e t h e e x t e n t t o

w h i c h t h e l a k e l e v e l s were i n f l u e n c e d by t h e c a n a l w i d e n i n g 23 m i l e s downstream. These s t u d i e s i n d i c a t e d t h a t t h e i n c r e a s e o f 0.21 f o o t i n d e p t h o f S a i n t Jean f o r a f l o w o f 45,000 c f s w o u l d r e d u c e t o a n e t i n c r e a s e o f 0.15 f o o t a t Lake Champla in. An

l a k e 1 eve1 . 0.04 f o o t a t S a i n t Jean f o r a f l o w o f 27,506 c t s w o u l d have an i n s i g n i f i c a n t a f f e c t on

- -

I t i s a p p a r e n t t h a t a q u a t i c v e g e t a t i o n has been g r o w i n g a b u n d a n t l y i n t h e Rouses P o i n t and R i c h e l i e u R i v e r a r e a s o f t h e l a k e r i v e r system. T h a t r e g i o n i s c l a s s i f i e d as

e l l t r oph i c o r n~eso t roph i c , which i n t l i c a t e s c o n s i d e r a l ~ l e b i o l o g i c a l i ~ c t i v i t y . Also, p t ~ y s i c a l i n s p e c t i o n o f the area has shown thc! gr0wt.h t o be ex tens i ve and t h i c k . Analyses o f ' seasonal v a r i a t i o n s o f l a k e l e v e l w i t.h respec t t o l a k e ou t f l ow have de i~~b r i s t ra ted an upward t r e n d p a r t i c u l a r l y f o r lower d ischarges. I t appears t h a t t h e t r e n d s t a r t e d around 1950. Th is c o r r e l a t e s w i t h t he a d d i t i o n a l use of' cher ' i ca l f c r t i l i z e r s i n a g r i c u l t u r a l p r a c t i c e s and t h e use o f phosphate-based detergents a f t e r World War I 1 which would l ead t o h i g h e r n u t r i e n t . i n p u t s t o t h e l a k e and probab ly t o g r e a t e r b i o l o g i c a l a c t i v i t y .

7.4.6 C l ima te

As ment ioned above, c l i m a t e can i n f l u e n c e l a k e stages b u t n o t t h e s tage-d ischarge r e l a t i o n s h i p s . Analyses o f t h e d i scha rge o f t h e R i c h e l i e u R i v e r a t F rye rs Rapids show an upward t r e n d thus i n d i c a t i n g h i g h e r i n p u t of p r e c i p i t a t i o n t o t h e bas in i n r e c e n t yea rs . Unless c o n t i n u i n g long- range c l i m a t i c t rends can be a n t i c i p a t e d , t h i s does n o t seem t o be a s i g n i f i c a n t f a c t o r t o be cons idered i n de te rm in ing t h e course o f a c t i o n t o be taken w i t h rega rd t o t h e R i c h e l i e u R ive r .

7.5 Conclusions

O f t h e many f a c t o r s analyzed and phenomena observed rega rd ing l a k e l e v e l changes and l a k e l e v e l - r i v e r f l o w r e l a t i o n s h i p s , t h e most c e r t a i n conc lus ion which can be drawn i s t h a t

t he s tage -ou t f l ow r e l a t i o n s h i p i s t r e n d i n g upward f o r . cause of these t rends i s p robab ly t h e growth o f

a q u a t i c v e g e t a t i o n i n t h e R i c h e l i e u R i v e r and i n t he Lake around Rouses P o i n t . The wide- '

n i n g o f t h e Chambly Canal had a snia l l one-t ime impact on the s tage-d ischarge r e l a t i o n s h i p and t h e u k r - t h a n - a v e r a g e p r e c i p i t a t i o n o f r e c e n t years has tended t o make t h e l a k e 6 wtk hk. mr, Since t h e e f f ~ t ~ f ~ F 1 ~ ~ ~ d y n a m i c s ? r e r e ~ 6 t ~ ~ ' n T B 1 ~ Z ~ d ~ t h ~ i ~ T i m ~ ~ ~ C t C i i ~ ~ ~ ~ ~ ~ w n , d@yh 'k -

/ +I($$4 b h u s , t he behav iour o f t h e l a k e l e v e l - r i v e r f l o w r e l a t i o n s h i p cannot be exp la ined

comp le te l y a t t h i s t ime. However, f o r p r o j e c t i n g t h e a b i l i t y o f any phys i ca l works i n t h e J R i c h e l i e u t o dea l w i t h u t u r e t rends, i t can be concluded t h a t o n l y t h e gated s t r u c t u r e s have t h e c a p a b i l i t y o f d e a l i n g w i t h t he t rends o r o t h e r sources o f d e v i a t i o n i n t h e l a k e l e v e l performance i n c l u d i n g t h e impact o f c l i m a t i c changes. The source o f t h i s c a p a b i l i t y i s t h e f l e x i b i l i t y i n o p e r a t i o n w i t h t h e ga te c o n t r o l (see F i g u r e 56) . S ince t h e w e i r e l e v a t i o n i s s e t f o r t h e f i x e d c r e s t s t r u c t u r e , adjustments cannot be made t o compensate f o r changes upstream, i . e . , a d d i t i o n a l growth o f a q u a t i c vegeta t ion . I n t h e case o f t he gated s t r u c t u r e s , t h e c o n t r o l l e v e l can be changed t o accommodate channel changes.

SECTION 8 OTHER STUDIES AND ANALYSES

8.1 F lood P r e d i c t i o n Model

2.1.1 General

I n o r d e r t o a i d r e g u l a t i o n ope ra t i ons o f Lake Champlain, no m a t t e r what scheme i s f i n a l l y adopted, a needed component i s a method f o r p r e d i c t i n g f u t u r e r u n o f f , p a r t i c u l a r l y d u r i n g the s p r i n g snowmelt season wke

Be to re such a

b e t t e r l a k e l e v e l management when i n c o r p o r a t

1

I n v e s t i g a t i o n s revea led t h a t t h e IJni t e d S ta tes Na t i ona l Weather Se rv i ce (NWS) - Hyd ro loq i c Research Labo ra to ry i n S i 1 ve r Spr ings, Maryland, was i n t h e process o f deve lop ing a runof f model f o r t h e Lake Champlain bas in i n co -ope ra t i on w i t h t h e H a r t f o r d R i v e r Forecast Center o f NWS. Th i s work was i n i t i a t e d independent ly o f t h e ICRB s tudy .

8.1.2 U.S. Na t i ona l Weather Se rv i ce P r e d i c t i o n Model

The r u n o f f model i s an a p p l i c a t i o n o f t he NWS Extended Streamflow P r e d i c t i o n model hlhich takes i n t o account c u r r e n t watershed c o n d i t i o n s such as snowpack, s o i l mo is tu re . ,etc.,and then p rov ides p r o b a b i l i t y d i s t r i b u t i o n s o f expected r u n o f f f o r t h e f u t u r e t i m e

I d u r a t i o n des i red . The i n p u t t o t h e model i nc ludes h i s t o r i c a l sequences o f tempera ture and p r e c i p i t a t i o n which, when rou ted th rough t h e model, p r o v i d e a range o f r u n o f f s wh ich c o u l d r e s u l t f rom a combinat ion o f c u r r e n t watershed c o n d i t i o n s and each h i s t o r i c a l i n p u t sequence. These r u n o f f f i g u r e s a r e then ordered and a p r o b a b i l i t y o f occurrence assigned

I t o each. T h i s a l l ows t h e use r t o s e l e c t t h e magnitude o f r u n o f f f o r t h e f requency event

bab i 1 i t y o f exceedence vo l ume c o u l d be t h e 10 pe r cen t chance o f exceedence

volume c o u l d be used as a bas i s f o r f l o o d warn ing t o l a k e shore owners where needed. 1 c o n s i s t s o f a v e r i f i e d watershed model

procedure f o r e x t r a p o l a t i n g t h e r e s u l t s ;

I t o t h e Champlain bas in . A t t h e present t ime, t h e i n d e x i n g i s accomplished by a p p l y i n g a

I 64,

. - c o e f f i c i e n t t o t h e Winooski model ou tpu t .

3- '- - Using h i s t o r i c a l data, t e s t s have shown c o n d i t i o n s and pe r i ods o f up

t o two months, t h e p r e d i c i t o g model q i ves o f h i s t o r i c a l means of

I , t h e r u n o f f model would be

exper ience i s gained and as more data a r e acqu i red by NWS. I 8.1.3 Use o f Model i n Regu la t i on Stud ies

To s tudy t h e e f f e c t i v e n e s s o f t h e r u n o f f p r e d i c t i o n model i n t h e l a k e r e g u l a t i o n i n v e s t i g a t i o n s , i t was necessary t o (produce " r u n o f f f o recas ts " f o r t h e 39 years o f h i s t o r i c a l h y d r o l o g i c c o n d i t i o n s which were used i n t h e r e g u l a t i o n model. NWS was a b l e t o produce f l o w f o r e c a s t s f o r t h e f i n a l 13 yea rs o f t h a t p e r i o d u t i l i z i n g watershed and c l i m a t i c da ta a v a i l a b l e ; however, da ta f o r p r i o r yea rs were u n a v a i l a b l e and thus o t h e r means o f r e p r e s e n t i n g what t h e f o r e c a s t model m igh t have produced were needed.

2 . B o i v e r t , Rene, P i n i s t P r e des r i c h e s s e s n a t u r e 1 l e s , Quebec, R i c h e l i e u R i v e r ,

I P r e l i n i i ~ a r y S tudy f o r t h e L o w e r i n g o f t h e S a i n t Jean Shoal .

I 3. E n v i ronrnent Canada, R e g u l a t i o n A n a l v s i s o f Lake Champlain, F i x e d H e i r A1 t e r n a t i v e , P l a n XAA, O c t o b e r 1975.

I 4. I n t e r n a t i o n a l C h a m p l a i n - R i c h e l l e u E n a i n e e r i n a Board, E e g u l a t i o n o f Lake Champla in, R e p o r t and Appendices, 1974.

I 5. I n t e r n a t i o n a l Champla in Waterway Eoard, Chaniplain I ; ' a ten~ay Feas i b i 1 i t y S t u d y ,

I P r e l i n i i t i a r y r e p o r t s and f i n a l r e p o r t , and Appendices 1964, 1965.

6 . I n t e r n a t i o n a l J o i n t Commission, R i c h e l i e u R i v e r Reniedial Norks , 1937

I 7 . I sachsen , Y . I J . , P o s s i b l e Ev idence f o r Contemporary Doming o f t h e A d i r o n d a c k

N o u n t a i n s , P!ew York , and Suggested I ~ r ~ p l i c a t i o n s f o r Reg iona l T e c t o n i c s and Se i srni c i t y , 1975.

8. S t a t e o f Vermont, Agency o f E n v i r o n m e n t a l C o n s e r v a t i o n , The B e h a v i o u r o f Lake Champla in, December 1076.

a . Nard, R o b e r t I., H i s t o r y o f Trends i n Lake Chatl iplain L e v e l , 1975.

CONTRACTORS ' REPORTS A l i l l SUPPORTING DATA

1 . H y d r a u l i c Model S tudy o f Water L e v e l ; o ~ ~ t r o l s on the Upper R i c h e l i e u R i v e r - L a S a l l f H y d r a u l i c L a b o r a t o r y , two r e p o r t s - Novemb~t 1575 and Oc tober 1976.

I 2 . R i v i e r e R i c h e l i p u , C o n t r G l e Sa I I I ~ Jean, l l t u d e Geotechn ique - L a b o r a t o i r e

d ' I n s p e c t i o n e t d l E s s a i s I n c . - Auqos t 1971.

3. S o i l I n v e s t i g a t i o n , R i c h e l l e u IUail1 i ' r ~ j e c t , S a i n t Jean shoal - Mon - Ter - Val - I n c . - Decealber 1974.

4. Proposed C o n c r e t e Weir , R i c h e l l e u R i v e r , S a i n t ,ledn, Qu6. - G e o t e c h n i c a l I n v e s t i g a t i o n by L a b o r a t o i r e d ' I n s p e c t i o n e t d ' r s s i i i s I n c . - Oc tober 1976

5. H y d r a u l i c Model T e s t s o f t h e Proposed Wei r f o r t h e R i c h e l i e u R i v e r a t S a i n t Jean, Que. , P. Engel and Y.L. Lau, Canada C e n t r e f o r I n l a n d Waters - March 1977.

6 . H y d r a u l i c Model T e s t s o f t h e Proposed Gated S t r u c t u r e f o r t h e R i c h e l i e u R i v e r v I l a u - A p r i l 1977. I

7. The S tage-D ischarge Relationship o f Lake C h a m p l a i n - R i c h e l i e u R i v e r , E n g i n e e r i n g D i v i s i o n , Water P l a n n i n g and Mariage~llent B ranch , E n v i ronrnent Canada - J u l y 1977. I Hydrographs o f ILake Chalnplain L c v e l s t o r a1 1 r e g u l a t i o n schemes c o v e r i n g t h e h i s tor ica.1 p e r i o d 1938-1 976. . I

9. D u r a t i o n Curves o f Lake C h a r n ~ l a i n l e v e l s and R i c h e l i e u R i v e r d i s c h a r g e s f o r a l l r e g u l a t i o n sche~i ies c o v e r i n g t h e h i s t o r i c a l p e r i o d 1938-1976.

TECHNICAL REPORT OF THE COMMI?TEE

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