Lake Saint Pierre facts for kids

Quick facts for kids Lake Saint Pierre (Lac Saint-Pierre)
View on the lake from Pointe-du-Lac (a sector of Trois-Rivières)
Lake Saint Pierre (Lac Saint-Pierre) Location in Quebec
Location	Canada, Quebec
Coordinates	46°12′15″N 72°49′56″W / 46.20417°N 72.83222°W / 46.20417; -72.83222
Type	Natural
Primary inflows	Saint Lawrence River, Yamaska River, Saint-François River, Nicolet River, Maskinongé River, Rivière-du-Loup River and Yamachiche River
Primary outflows	Saint Lawrence River
Basin countries	Canada
Max. length	32 km (20 mi)
Max. width	14 km (9 mi)
Surface area	353 km2 (136 sq mi)
Average depth	3 m (9.8 ft)
Max. depth	11.3 m (37 ft)
Surface elevation	3.3 m (11 ft)
Islands	Sorel Islands
Settlements	Trois-Rivières, Berthierville
Ramsar Wetland
Official name: Lac Saint Pierre
Designated:	25 May 1998
Reference #:	949

Lake Saint Pierre (in French, Lac Saint-Pierre) is a large lake in Quebec, Canada. It is actually a wider part of the Saint Lawrence River, located between the cities of Sorel-Tracy and Trois-Rivières. This lake is found northeast of Montreal and southwest of Quebec City. It marks the beginning of the estuary of Saint Lawrence, where the river starts to mix with ocean water.

The lake is about 32 kilometers (20 miles) long and 14 kilometers (9 miles) wide. It is an important part of the Saint Lawrence Seaway, which is a system of canals and channels for ships. Lake Saint Pierre is also a special nature reserve, including its shores, islands, and wetlands. It is recognized as a Ramsar site and a Biosphere Reserve. This is because it has many marshes and wetlands that are home to lots of waterfowl (birds that live near water).

Many fun activities happen on the lake, especially in summer. These include fishing, boating, sailing, swimming, and watching nature. Sport fishing is very popular, even ice fishing in winter, especially near Pointe-du-Lac. Around the lake, you can find places like marinas, hotels, restaurants, and places to rent gear for outdoor activities.

Where is Lake Saint Pierre?

About 12,500 years ago, after the last ice age, melting glaciers created a huge body of water called the Champlain Sea. This ancient sea covered a large area, including where Lake Saint Pierre is today. Over thousands of years, the water level dropped, forming the landscape we see now.

The lake's watershed, which is the area of land that drains into the lake, is huge. It covers about 990,000 square kilometers (382,000 square miles). Most of this area is in the United States and Ontario, with a smaller part in Quebec. Lake Saint Pierre is connected to many different regions and towns.

The lake is located in several different areas called Regional County Municipalities. These include Nicolet-Yamaska, Maskinongé, D'Autray, and Pierre-De Saurel. The city of Trois-Rivières also touches the lake.

Many towns are located along the lake's shores:

• North shore: Berthierville, Maskinongé, Louiseville, Yamachiche, and Trois-Rivières (Pointe-du-Lac area).
• South shore: Saint-Joseph-de-Sorel, Pierreville, Baie-du-Febvre, and Nicolet.

Rivers Flowing into the Lake

Lake Saint Pierre gets its water from the Saint Lawrence River and 14 other main rivers.

• North bank rivers: Maskinongé River, Rivière du Loup (Mauricie), Yamachiche River, Glaises stream, and Sables River.
• South bank rivers: Yamaska River, Saint-François River, Colbert River, Landroche River, Des Frères River, Brielle River, Lemire River, Camille-Roy River, and Nicolet River.

The lake is quite shallow, with an average depth of only three meters (10 feet). However, the shipping channel, which is dug deeper for large ships, has a maximum depth of 11.3 meters (37 feet).

How the Lake Got its Name

The lake was named by Samuel de Champlain on June 29, 1603. This was the feast day of Saint-Pierre (Saint Peter). The Abenaki Indigenous people called the lake Nebesek, which means "at the lake." Earlier, in 1535, Jacques Cartier had named it "Angoulême" during his second trip to Canada.

Amazing Nature and Wildlife

Lake Saint Pierre is a very important place for nature. It is a key stopping point for hundreds of thousands of migrating waterfowl (like ducks and geese). It is also a major nesting area for herons. More herons nest here than anywhere else in North America! In 1998, the lake was recognized as a wetland of international importance under the Ramsar Convention.

Wildlife experts have found 23 different kinds of mammals around Lake Saint Pierre. One of the most common is the muskrat (Ondatra zibethicus), which lives in large numbers around the lake.

Lake Saint Pierre Biosphere Reserve

Lake Saint Pierre was named a Biosphere Reserve by UNESCO in 2000. A biosphere reserve is a special area recognized for its unique natural environment and for showing how people and nature can live together. The Lake Saint Pierre biosphere reserve covers 480 square kilometers (185 square miles).

This reserve is home to nearly 290 species of birds, about 90 species of fish, and 27 rare plant species. It is a truly special place for biodiversity.

Grande-Île Wildlife Sanctuary

The Grande-Île (Great Island) Wildlife Sanctuary is located on Grande-île within the Archipelago of Saint-Pierre Lake. This sanctuary was created in 1992 to protect one of the largest heron colonies in North America. It provides a safe home for more than 5,000 herons.

Nicolet Bird Sanctuary

The Nicolet Bird Sanctuary is a protected area of 30 square kilometers (11.6 square miles). It is a vital resting place for migrating ducks and Canada geese. It is also a nesting area for many waterfowl. This site was recognized as a rest area in 1969 and a refuge in 1982.

History of the Lake

Lake Saint Pierre has played a big role in the history of French Canada. Because it's the last freshwater basin of the Saint Lawrence River, its location made it important for fishing, hunting, and transportation. The Saint Lawrence Seaway passes through it, and people have used the lake for pleasure boating, building towns, and even for winter ice roads and ferries.

In 1609, Samuel de Champlain wrote about the lake, mentioning two rivers on the south side. He described the area as "very beautiful and in beautiful and good country."

Protecting the Environment

Since the 1970s, the water quality of Lake Saint Pierre has gotten much better. This is thanks to many efforts, including:

• Building water filtration centers upstream to clean water from cities and industries.
• Cleaning up the banks and bottom of the river by local communities and organizations.
• Changing how many products are made to reduce harmful pollution.
• Making sure homes near the lake have proper septic tanks.
• Banning boats from dumping waste water.
• Increasing recycling to reduce trash in nature.
• Better monitoring of water activities by groups like the Canadian Coast Guard.

However, large ships using the Saint Lawrence Seaway can cause waves that wear away the shoreline. Also, the shipping channel has changed the natural flow of the river in some places. This can cause water to become still near the banks, leading to silt building up.

Challenges and Events

Throughout its history, Lake Saint Pierre has seen some difficult events:

• Flooding: Spring floods, usually from April to May, can cause the lake to rise. Strong winds and high tides can make this worse. These floods can damage buildings, docks, and fishing equipment along the shore.
• Accidents: Sadly, there have been accidents like drownings, or people getting lost on the ice during winter.

In the past, when wood was transported by river, logs would sometimes break free and float on Lake Saint Pierre. These floating logs could damage boats. Today, Highway 40 on the north shore acts as a barrier, protecting the land from high water levels or storms. For example, the floods in April and May 2017 caused significant damage along the lake's shores.