Lavallière Bay 2011-2012

Final Project Report: Lavallière Bay 2011-2012(pdf)

12-29Photo: Aeriel view of St. Louis Marsh
Credit: DUC 

Goals and Objectives

To mitigate the various problems in the Lavallière Bay, DUC and the Ministry of Natural Resources and Wildlife decided to set up a new concept of wildlife development to preserve this marsh and to restore this habitat of preference for waterfowl, fish and other wildlife groups. These new developments are the answer to the various problems generated mainly by agriculture, but rather a wildlife solution making it possible to ensure visitation of the bay by abundant and diversified wildlife.

The main objectives of the overall project of restoring the Lavallière Bay are:

1. To develop and implement an agricultural action plan in order to improve water quality and reduce the load of sediments and nutrients.

2. To diversify the types of wetlands by increasing the proportion of deep marshes and the total area of open water for waterfowl.

3. To consolidate the developments currently present on the site (marsh, (water) control work and fishway).

4. To improve the access of fish to the shallow marsh.

5. To modify the hydrodynamics in order to instigate the development of vegetation and reduce sedimentation.

6. To consolidate the lands bordering the bay (wet meadows located on the high grounds).

7. To bring solutions to the expansion of invading exotic species (propagation and establishment).



The anticipated work within the framework of phase I of the project is summarized by the creation of dykes, the installation of a water level monitoring control and the installation of a pumping station, thus creating a marsh of 110 hectares for the migration, reproduction and breeding of waterfowl broods.

The main technical activities are:

1. Construction of dykes;

2. Construction of a water level monitoring control;

3. Construction of a pumping station.

The schedule for the completion of the work in phase I is anticipated to be from August to October 2011. The completion of this work will require the use of heavy machinery (hydraulic excavator, bulldozers, 10-wheel trucks, trimmer/brushcutter).


Specific Habitat Products/Results Supported by WHC’s Contributions

Wetlands and the river floodplains have important ecological roles and are essential to the maintenance of the health of the aquatic ecosystems of the St. Lawrence River. However, these environments are constantly subjected to anthropic pressures (i.e. urbanization, agriculture, commercial navigation) and their total area is continuously reduced. Phase I of the project of restoring Lavallière Bay will make it possible to restore a total area of 110 hectares of marsh and return optimal wildlife to the area.

The assessment of the impacts on wildlife and its habitats is positive. The development of this marsh (Saint-Louis) will offer the conditions that are essential to the development and maintenance of aquatic and diversified vegetation which are indispensible to a multitude of wildlife species, such as waterfowl, aquatic birds, amphibians, reptiles and aquatic mammals, in addition to increasing the total area of habitat available. The wildlife user of the marshes, will have available, shelter, food and reproduction sites. Moreover, the development work of the Saint-Louis marsh will make it possible to diversify the wildlife development of Lavallière Bay.


Benefits to Waterfowl, Wetlands-Associated Species, and/or Other Wildlife

Lavallière Bay is used by waterfowl during migrations and as a rest area, for feeding, reproduction and brood-rearing. In addition to Canada Geese, several species of ducks are found there, including the Pintail (Anas acuta), Gadwall (Anas strepera), Blue-winged Teal (Anas discors), Black Duck (Anas rubripes), Mallard Duck (Anas platyrhynchos), Shoveler (Anas clypeata), American Wigeon (Anas americana), Wigeon (Anas penelope), Wood Duck (Aix sponsa) and Green-winged Teal (Anas crecca), Redhead (Aythya americana), Ring-necked Duck (Aythya collaris), Hooded Merganser (Lophodytes cucullatus) and Common Goldeneye (Bucephala clangula). The Wood Duck, Hooded Merganser and Common Goldeneye use the natural cavities of trees in marshy forests to nest, as well as the nesting boxes installed by the Société d’aménagement de la Baie Lavallière

Several other species of aquatic birds benefit from the habitats of the bay, such as herons (Great Blue Heron (Ardea herodias), Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax)), who use the bay for feeding. In addition, the American Bittern (Botaurus lentiginosus), Green Heron (Butorides virescens) and Least Bittern (Ixobrychus exilis) are frequent nesting birds. Birds of prey have also been inventoried such as, among others, the Eastern Screech-Owl (Megascops asio), Great Horned Owl (Bubo virginianus), Northern Saw-whet Owl (Aegolius acadicus) and the Short-eared Owl (Asio flammeus).

Lavallière Bay also offers interesting conditions for mammals, such as the Muskrat (Ondatra zibethicus), Raccoon (Procyon lotor), White-tailed Deer (Odocoileus virginianus), Striped Skunk (Mephitis mephitis), Red Fox (Vulpes vulpes), Beaver (Beaver canadensis), American Mink (Mustela mink) and the Little Brown Bat (Myotis lucifugus).

Lavallière Bay is also recognized for its strong populations of amphibians, mainly represented by the Leopard Frog (Rana pipiens), Green Frog (Rana clamitans melanota), and the Bullfrog (Rana catesbeiana). The Wood Frog (Rana sylvatica), Northern Spring Peeper (Pseudacris crucifer crucifer), Blue-spotted Salamander (Ambystoma side) and the American Toad (Bufo americanus americanus) have also been observed.

A species of turtle, the Snapping Turtle (Chelydra serpentina serpentina), also reproduces in the bay and is abundant there. The Painted Turtle (Chrysemys picta picta) was also observed on occasion and it is believed that several other species of reptiles find favourable habitats there, such as the Common Garter Snake (Thamnophis sirtalis) which has already been seen.


Relevance to Habitat Planning, Decision Making and/or Management

Management and enhancement of the site are assured by the Société d’aménagement de la Baie Lavallière (Development Corporation of Lavallière Bay). Activities such as hunting for waterfowl (Regroupement des sauvaginiers du lac Saint-Pierre/Coalition of Waterfowlers of Lake Saint-Pierre), trapping of muskrat, sport fishing, excursions in the marsh, and education for young people are organized in the bay. An interpretation centre (Maison du marais/House of the marsh) and infrastructures are available on the site to receive visitors and school groups. A nature trail, 1.3 km in length with its observation tower and rest stops, takes us to the heart of Lavallière Bay by using educational signs on wildlife, plants and the functioning ecosystem of this unique environment. The trail ends at a fishway for fish.

The Société d’aménagement de la Baie Lavallière (Development Corporation of Lavallière Bay) also set up, in the bay, a network of duck nest boxes for the restoration of habitat for the Wood Duck.


Project Location

Lavallière Bay is located on the southern bank of the St. Lawrence River, approximately 80 km northeast of Montreal and nearly 15 km east of Sorel. It is comprised of a group of lowlands located between the downstream end of the archipelago of Lake Saint-Pierre and the point of the junction of the Yamaska River with Lake Saint-Pierre. Lavallière Bay presents a particular interest since it is located at the height of what is one of the priority areas for the preservation of wetlands of the St. Lawrence River. Indeed, this fluvial lake is recognized by UNESCO as a World Biosphere Reserve since 2000. Taking into account its location in the heart of the Atlantic migratory flyway, Lavallière Bay represents a territory of great interest as a migratory stopover for waterfowl. Composed of marshes, swamps and wet meadows, the bay contributes in a significant manner to the wildlife richness of Lake Saint-Pierre. At the present time, Lavallière Bay is recognized as a priority habitat for waterfowl according to the Act on conservation and development of wildlife. More recently, it was also made the subject of great interest for the Funds of restoration of fish habitat.


Project Contact

For more information on this project, please contact Sylvain Gaudreau, Engineer, Team Leader – Restoration and Management of Habitats, Ducks Unlimited Canada, Quebec, QC