Lake Winnipeg Quick Facts

The Lake Winnipeg watershed is the second largest watershed in Canada and includes parts of four provinces and four U.S. states.

The Lake Winnipeg drainage basin is nearly 1,000,000 km² in size and is home to more than 7 million people.

Lake Winnipeg, the last remains of glacial Lake Agassiz, lies on the boundary between the low-relief Interior Plains and the southwestern Canadian Shield.

Several major rivers flow into Lake Winnipeg including the Red, Winnipeg, and Saskatchewan rivers.  These three rivers make up on average more than 60% of the total river flow into Lake Winnipeg.

Some of the other rivers that flow into Lake Winnipeg include the Poplar, Berens, Pigeon, Manigotagan, Dauphin, Fisher, and Icelandic rivers.

Only one river flows out of Lake Winnipeg, the Nelson River. The outflow of the lake has been regulated for hydro-electric power generation since 1976 making Lake Winnipeg the third largest hydro-electric reservoir in the world.

Water moves through Lake Winnipeg over a period of on average about 3 to 5 years.  This is relatively fast compared to other large lakes such as Lake Superior where the water residence time is 191 years.

Physical Characteristics

Lake Winnipeg is the 10th largest lake in the world by surface area.

The surface area of Lake Winnipeg is about 23,750 km² and covers about 3.7% of the surface area of the Province of Manitoba.

Lake Winnipeg is about 436 kilometres  in length, about the same distance as a drive to Brandon from Winnipeg...and back!

At its widest point, Lake Winnipeg is about 111 kilometres across.

On average, the lake is about 12 metres deep but at a point off the north east shore of Black Island, Lake Winnipeg reaches its maximum depth of about 36 metres.

With its many bays, harbours, and points, the shoreline of Lake Winnipeg is about 1,750 kilometres long.

The volume of Lake Winnipeg is 284 cubic kilometres (1 kilometre wide by 1 kilometre high by 1 kilometre long), equivalent to more than 6 billion times the volume of a standard 14 by 28 foot backyard pool.

Lake Winnipeg consists of a large, deeper north basin and a smaller, comparatively shallow south basin. Lake Winnipeg is shallow relative to other large lakes, with an average depth of 9 metres in the south basin and 13.3 metres in the north basin. The two basins are separated by the Narrows through which waters from the south basin ultimately flow northward.

Because of its shallow depth, the water column of Lake Winnipeg is typically not stratified with bottom waters within 1 to 2oCelcius of surface water temperatures.

Eutrophication, Water Chemistry, and Aquatic Life

Nutrient loading to Lake Winnipeg and concentrations of nutrients in Lake Winnipeg have increased over the past several decades.

Nutrient increases in Lake Winnipeg in the 1990s led to a doubling of phytoplankton biomass and a shift to cyanobacteria (blue-green algae) dominance of the phytoplankton community.

Phosphorus concentrations are almost three times higher in the south basin on Lake Winnipeg as compared to the north basin. 

Nitrogen concentrations are slightly higher in the south basin of Lake Winnipeg as compared to the north basin.

Higher nutrient concentrations generally occur at the very south end of the lake and decline moving northwards. Elevated nutrient concentrations at the southern end of Lake Winnipeg are likely associated with the nutrient-rich inflow of the Red River.

Six aquatic invasive species are known to occur in Lake Winnipeg. These are the common carp, rainbow smelt, white bass, the cladoceran Eusbomina coregoni, Asian tapeworm, and spiny water flea.  Although it is difficult to predict impacts to Lake Winnipeg, these species may potentially alter ecological relationships among native species, affect ecosystem health and function, the economic value of ecosystems, and human health.  

Economic Value

More than 23,000 permanent residents live in 30 communities along the shores of Lake Winnipeg, including 11 First Nations communities.

Seven Manitoba Provincial Parks are located on the south basin of Lake Winnipeg including Hecla/Grindstone, Beaver Creek, Camp Morton, Winnipeg Beach, Elk Island, and Grand Beach.

In 2010 - 2011, 1069 licensed fishers and their helpers were employed in the commercial fishery on Lake Winnipeg.

During the 2010 - 2011 season, 4,498,370 kg (round weight) of walleye were caught by commercial fishers on Lake Winnipeg. Harvests of lake whitefish and sauger were 1,503,881 and 223,840 kg (round weight), respectively.

In 2010 – 2011, the total landed value of commercial fish production of Lake Winnipeg was $16,259,317.

Events and Entertainment

Lake Winnipeg is host to numerous festivals every year. Lake Winnipeg helped to host the Pan Am Games in 1999 and the World Boardsailing Championships in 1994.

Lake Winnipeg was used as a set for the movie K19 starring Harrison Ford.

Lake Winnipeg and the community of Winnipeg Beach were used as the set of the television show Falcon Beach.  The show is a unique Canadian TV series in that two versions of each episode were filmed. The first version was for Canadian markets and uses Canadian geographic references and terminology. The second version was done for the United States markets and uses American geographic references and terminology.  The program is a teen drama set in the fictional resort town of Falcon Beach, Manitoba (New England for U.S. viewers), The series ran from 2005 – 2007 and continues to be popular in many countries.