Dike repairs at Les Cèdres Generating Station€¦ · An embankment dike was also built upstream of the . powerhouse to create a headrace canal that would direct water from the Fleuve

DIKE REPAIRS AT LES CÈDRES GENERATING STATION

INFORMATION BULLETIN

FALL 2016

Les Cèdres generating station was built in 1913 and 1914. An embankment dike was also built upstream of the powerhouse to create a headrace canal that would direct water from the Fleuve Saint-Laurent into the powerhouse.

A number of studies and inspections of this dike conducted by Hydro-Québec show water infiltration and seepage from the headrace canal. As a result, to ensure the long-term operability of the facilities, Hydro-Québec must repair the fill of the embankment dike of the Les Cèdres headrace canal.

The purpose of this project is to improve the watertightness and stability of the dike and to minimize the risk of erosion of its foundation.

2

!

Vaudreuil-Dorion,V Notre-Dame-de-l'Île-Perrot,

V

Saint-Clet,M

TNO aquatiquede la MRC de

Vaudreuil-Soulanges,NO

LesCèdres,M

Beauharnois,V

Coteau-du-Lac,V

Pointe-des-Cascades,VL

Salaberry-de-Valleyfield, V

Saint-Étienne-de-Beauharnois, M

TNO aquatique de la MRC deBeauharnois-Salaberry,NO

Saint-Stanislas-de-Kostka, M

Beauharnois-Salaberry

(MRC)

Vaudreuil-Soulanges

(MRC)

20

30

30

530

338

201

338

132

Boulevard Gérard-Cadieux

Boulevard P

ie XII

Chem

in Saint-Dom

inique

Rang Sainte-Marie Est

Chemin du Fleuve

Chemin du

Canal O

uest

Chem

in Saint-Féréol

Chem

in du Golf

Chem

in Sainrt-Emm

anuel

Rang Sainte-Marie Ouest

Chem

inS

aint-Antoine

Saint-Timothéedam

l'Île-Juillet-2dam

Pointe-du-Buissondam

Les Cèdresdike

l'Île-Juillet-1dam

Les Cèdrespowerhouse

Les Cèdres

Saint-Timothée sector

Salaberry-de-Valleyfield

Pointe-des-Cascades

Coteau-du-Lac

Île de Salaberry

Canal de

Beauharnois

Rivière

ÎleBienville

Île desCascadesÎle De

Joybert

Île auxChats

ÎleJuillet

Barrage de Beauharnois

Îled'Aloigny

Saint-Charles

FleuveSaint-Laurent

Rivière desOutaouais

Le Petit

Canal

Cours d'eau Leboeuf-Léger

Rivière à la G

raisse

Saint-Grégoire

L'Ancien Canal

Canal

de S

oulan

ges

Canal de Soulanges

Ruisseau Chamberry

Ruisseau

A

74°0'

74°0'

74°4'

74°4'

74°8'

74°8'

73°56'

45°2

0'45

°18'

45°1

6'45

°14'

73°5

6'

45°20'45°18'

45°16'45°14'

Les Cèdres dam

Gravity dam

Spillway(decommissioned)

Inverted filter

Inverted filter Inverted filter

Sealing work

Slope stabilizationSlope stabilization

Île auxVaches

A

!!(

Zone 2

Île à l'Ail

Zone 1

!!(

!!(Zone 2

A

Les Cèdres

Saint-Timothée basin(winter low water)

Fleuve Saint-LaurentLes Cèdres headrace canal

île Saveuse

Les Cèdres dike

%

Zone 3


Pointe-du-Buissonbasin

120

kV 1

263-

1470

120

kV 1

434-

1435

(P)735 kV 7042

!!A

!!A

0 1 2 km

MTM, Zone 8, NAD83 (CSRS)

0002c_buc1_tet_014_projet_161018.mxd

Infrastructure

Hydropower generating station

Dam

Highway

Provincial highway

Secondary highway

Local road

30

132

338

BoundaryRegional countymunicipality (RCM)Municipality

Document for information purposes only. For any other use, please contact Géomatique, Hydro-Québec Équipement et services partagés.

0 75 150 m


Planned structure

Above water

Under water (not visible)

Direction of flow

Bike path!!(

A

PROJECT DESCRIPTIONNorth side of the dikeHydro-Québec will perform sealing work over a distance of about 350 m (zone 1) to reduce water infiltration into the embankment dike. This involves partially excavating the slope of the dike and adding more than 100,000 m3 of a mix of till, granular material and rock.

The water level in the Les Cèdres headrace canal will be maintained at its usual level throughout the work. A containment curtain will be installed in the headrace canal to confine particles suspended during placement of the new material.

South side of the dikeHydro-Québec will add an inverted filter over a distance of about 1,190 m in the Saint-Timothée basin (zone 2) and about 120 m in the Pointe- du-Buisson basin (zone 3). Composed of several layers of granular fill, the inverted filter is designed to prevent particulate matter from migrating outside the embankment in case of infiltration and thus prevent erosion of the foundation of the dike. Building the inverted filter will involve preparing the foundation and adding about 70,000 m3 of granular material and rock.

Hydro-Québec also plans to stabilize the slope over a distance of about 175 m in the Saint-Timothée basin (zone 2) and about 125 m in the Pointe-du-Buisson basin (zone 3). This will involve dumping about 10,000 m3 of granular material and rock on the side of the dike.

The work on the south side of the dike will be performed when water levels are lowest in the Saint-Timothée and Pointe-du-Buisson basins , that is, between November and April.

Vegetation controlHydro-Québec has to cut down some of the trees on the dike to get to the work areas. Since trees can weaken a dike, compromising its stability, Hydro-Québec will determine if other trees on the dike, outside the work area, also need to be felled.

3

!


V

Saint-Clet,M



LesCèdres,M

Beauharnois,V

Coteau-du-Lac,V







(MRC)

Vaudreuil-Soulanges

(MRC)

20

30

30

530

338

201

338

132


Boulevard P

ie XII

Chem

in Saint-Dom

inique


Chemin du Fleuve

Chemin du

Canal O

uest

Chem

in Saint-Féréol

Chem

in du Golf

Chem

in Sainrt-Emm

anuel


Chem

inS

aint-Antoine

Saint-Timothéedam

l'Île-Juillet-2dam


Les Cèdresdike

l'Île-Juillet-1dam


Les Cèdres



Pointe-des-Cascades

Coteau-du-Lac

Île de Salaberry

Canal de

Beauharnois

Rivière

ÎleBienville


Joybert

Île auxChats

ÎleJuillet


Îled'Aloigny

Saint-Charles

FleuveSaint-Laurent


Le Petit

Canal


Rivière à la G

raisse

Saint-Grégoire

L'Ancien Canal

Canal

de S

oulan

ges

Canal de Soulanges

Ruisseau Chamberry

Ruisseau

A

74°0'

74°0'

74°4'

74°4'

74°8'

74°8'

73°56'

45°2

0'45

°18'

45°1

6'45

°14'

73°5

6'

45°20'45°18'

45°16'45°14'

Les Cèdres dam

Gravity dam


Inverted filter


Sealing work


Île auxVaches

A

!!(

Zone 2

Île à l'Ail

Zone 1

!!(

!!(Zone 2

A

Les Cèdres



île Saveuse

Les Cèdres dike

%

Zone 3



120

kV 1

263-

1470

120

kV 1

434-

1435

(P)735 kV 7042

!!A

!!A

0 1 2 km



Infrastructure


Dam

Highway

Provincial highway

Secondary highway

Local road

30

132

338



0 75 150 m


Planned structure

Above water


Direction of flow

Bike path!!(

A

!


V

Saint-Clet,M



LesCèdres,M

Beauharnois,V

Coteau-du-Lac,V







(MRC)

Vaudreuil-Soulanges

(MRC)

20

30

30

530

338

201

338

132


Boulevard P

ie XII

Chem

in Saint-Dom

inique


Chemin du Fleuve

Chemin du

Canal O

uest

Chem

in Saint-Féréol

Chem

in du Golf

Chem

in Sainrt-Emm

anuel


Chem

inS

aint-Antoine

Saint-Timothéedam

l'Île-Juillet-2dam


Les Cèdresdike

l'Île-Juillet-1dam


Les Cèdres



Pointe-des-Cascades

Coteau-du-Lac

Île de Salaberry

Canal de

Beauharnois

Rivière

ÎleBienville


Joybert

Île auxChats

ÎleJuillet


Îled'Aloigny

Saint-Charles

FleuveSaint-Laurent


Le Petit

Canal


Rivière à la G

raisse

Saint-Grégoire

L'Ancien Canal

Canal

de S

oulan

ges

Canal de Soulanges

Ruisseau Chamberry

Ruisseau

A

74°0'

74°0'

74°4'

74°4'

74°8'

74°8'

73°56'45

°20'

45°1

8'

45°1

6'45

°14'

73°5

6'

45°20'45°18'

45°16'45°14'

Les Cèdres dam

Gravity dam


Inverted filter


Sealing work


Île auxVaches

A

!!(

Zone 2

Île à l'Ail

Zone 1

!!(

!!(Zone 2

A

Les Cèdres



île Saveuse

Les Cèdres dike

%

Zone 3



120

kV 1

263-

1470

120

kV 1

434-

1435

(P)735 kV 7042

!!A

!!A

0 1 2 km



Infrastructure


Dam

Highway

Provincial highway

Secondary highway

Local road

30

132

338



0 75 150 m


Planned structure

Above water


Direction of flow

Bike path!!(

A

2016E1249-A

100 %

MAIN IMPACTS ANTICIPATED DURING THE WORKIncrease in trafficDuring the work, traffic will increase along route 132 at Salaberry-de-Valleyfield, between exit 9 of highway 530 and Saint-Timothée dam. About 20 trucks per hour will travel this road during the day during normal working hours to transport the required material.

Hydro-Québec will take all necessary measures to ensure public safety. For example, flaggers will be employed, in particular near École Marie-Rose.

Closure of portions of the bicycle network of the Îles-de-Saint-Timothée regional parkDuring certain work periods, Hydro-Québec will have to close part of the bike path on Saint-Timothée dam and on the dike. Hydro-Québec will communicate regularly with park managers to let them know when the bike path will be closed.

The work will not affect activities at Saint-Timothée beach.

Natural habitatsThe work will affect aquatic habitats at the foot of the dike. Measures will be taken to minimize habitat loss, for certain fish species in particular.

PUBLIC PARTICIPATIONIn cooperation with the host community, Hydro-Québec will implement a public participation process as part of the studies for the project. This will make it possible for the expectations and concerns expressed by the public and by key community stakeholders to be taken into account so the project can be adapted to local realities.

ENVIRONMENTAs this project is subject to section 31.1 of the Environment Quality Act, Hydro-Québec will file an environmental impact statement with the Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques. A public hearing may be held by the Bureau d’audiences publiques sur l’environnement (BAPE).

TIME TABLE

Public information meetings Fall 2016 – Winter 2016-2017

Permitting Winter 2016-2017 – Summer 2018

Construction Fall 2018 – Spring 2020

FOR MORE INFORMATION

INFO-PROJECT Line 1 8 7 7 6 5 3-1 1 3 9JONATHAN PETIT Advisor – Community Relations – Richelieu Direction – Affaires régionales et collectivités 705, boul. Clairevue Ouest, 1er étage Saint-Bruno-de-Montarville (Québec) J3V 6B6

E-mail: [email protected]

hydro.quebec/des-cedres

Ce document est également publié en français. This document is a translation of the original French text.

Documents

Dike repairs at Les Cèdres Generating Station€¦ · An embankment dike was also built upstream of the . powerhouse to create a headrace canal that would direct water from the Fleuve