Red River Delta: The Red River enters Lake Winnipeg through a complex delta known as the Netley Marsh, seen here in August 2011. The river's mouth is about 34 miles northeast of Winnipeg and 550 river miles from its origin at Breckenridge, Minn. John Stennes / Forum Communications Co.
Devils Lake is an exception, but by and large water flows out of the Dakotas and Minnesota. Water flows into Manitoba.
Lake Winnipeg is a kind of bathtub collecting water from a huge area near the heart of North America. (The geographical center of the continent near Rugby, N.D., is in the Lake Winnipeg basin.)
Rivers feeding the lake pick up sediments and chemicals. Among these phosphorous is of special concern, because it fertilizes the lake, enabling huge algae blooms that consume oxygen and endanger other life in the lake — a process called eutrophication.
Some of this comes from the U.S. portion of the drainage basin. Although the Red River contributes a small share of the lake’s water, it contributes the largest share of phosphorous to the lake. Much of it comes from the Winnipeg urban area, which is drained by the Red River.
Non-native species reach the lake through these rivers, too. Carp entered Lake Winnipeg from the Red River; rainbow smelt arrived from rivers draining northwestern Ontario.
These factors have made Lake Winnipeg a focus of concern in Canada.
To most American Midwesterners, Lake Winnipeg is probably best known as the blue spot at the top of television weather maps.
To Canadians, Lake Winnipeg is “the sixth great lake.”
Protecting the lake has been at the heart of Canadian objections to water development projects in North Dakota, including the Garrison Diversion project and a Devils Lake outlet.
Mike Jacobs – Project coordinator – Living With Water
Bobbi Berberich DuChamp - Forum Communications
Continental drainage system
Lake Winnipeg has the largest drainage area of any freshwater lake in the world, almost 400,000 square miles.
Water reaches Lake Winnipeg from the Rocky Mountain front in Alberta, the farmlands of Saskatchewan, the forests of northwestern Ontario and the Red River Valley of North Dakota, Minnesota and Manitoba. A small portion or northeastern South Dakota drains to the lake. So does Montana’s Glacier National Park. Water is discharged from the lake through the Nelson River into Hudson Bay.
Bobbi Berberich DuChamp - Forum Communications Co.
- Large: 9,465 square miles/11th largest freshwater lake in the world.
- Long: 258 miles south to north.
- Shallow: Average depth 39 feet (118 feet at the narrows between north and south basins).
- Wild: Area on the eastern shore considered for UNESCO World Heritage Site.
- Valuable: Fishing produces about $30 million (Canadian) yearly, much of it by native fishermen. Recreation and tourism contribute $100 million. The lake also functions as a reservoir, producing electricity, some of it exported to the United States.
- Valued: More than 23,000 people live in 30 communities, including 11 aboriginal communities, on its shores.
- Vulnerable: Huge drainage area means lake takes in large amounts of sediment, fertilizers, run-off from hog operations and municipal wastes. These factors combine to cause occasional huge algae blooms that endanger the lake’s ecosystem.
