Hey there, time traveller!
This article was published 7/6/2011 (2011 days ago), so information in it may no longer be current.
One of the byproducts of Manitoba's long, protracted flood fight this spring is a greater awareness of the geography of this province.
Once-obscure communities such as Lake St. Martin First Nation, Hoop and Holler Bend and Twin Lakes Beach have been thrust into the provincial spotlight, albeit for reasons none of their residents would ever wish upon their worst enemies.
The flood has also increased awareness of the way water flows through rivers, streams and artificial channels in southern Manitoba. Never before have provincial flood-fighters spoken so much about the Portage Diversion, the Elm River and the Shellmouth Dam.
But as the focus of the flood shifts to the less populated regions around the province's five "great lakes," the flood is once again testing the geographic knowledge of the average Manitoban.
Winnipeggers, for example, can be forgiven for being confused by the fact the Dauphin River flows nowhere near Dauphin Lake, never mind the city of Dauphin.
Or by the fact the expanding Shoal Lakes of the Interlake have no relation to the town of Shoal Lake near Riding Mountain or the Ontario-border Shoal Lake that provides Winnipeg with its drinking water. Or by the fact there is no longer a river delta at Delta Beach or Delta Marsh.
In an effort to get a handle on where the flood is moving next, here's a primer of the five "great lakes" in the centre of the province, each a remnant of glacial Lake Agassiz:
1. Lake Winnipeg
At 24,514 square kilometres, Manitoba's best-known lake is both the 11th-largest in the world and the largest lake to be contained within the borders of any individual Canadian province. It drains north through the Nelson River to Hudson Bay.
Lake Winnipeg has been partly regulated by Manitoba Hydro since 1976 through the operation of the Jenpeg Generating Station at one of two forks on the Nelson River, 90 kilometres north of the lake's outlet, as well as a series of deep channels that allow water to flow out even when the lake is covered in ice.
Lake Winnipeg is nonetheless on the rise, as inflows into the lake from its major tributaries -- the Red, Winnipeg, Saskatchewan and Dauphin rivers -- has exceeded the maximum outflow of 155,000 cubic feet per second all spring. The lake is expected to rise as much as another eight inches by mid-July.
This means beaches, beachfront communities and fishing towns along both of Lake Winnipeg's basins will be flooded all summer, including popular tourist destinations such as Gimli, Winnipeg Beach and Grand Beach Provincial Park.
Desirable range: 711 to 715 feet above sea level
Current level: 716.3 feet
Predicted summer peak: 717 feet
Record peak: 718.2 in 1974
2. Lake Winnipegosis
At 5,370 square kilometres, Lake Winnipegosis is the 27th largest lake in the world and the largest unregulated lake in Manitoba. It is located west of Lake Winnipeg and north of Lake Manitoba. It drains southeast into Lake Manitoba through Waterhen Lake and the Waterhen River.
Since consistent monitoring began in 1940, Lake Winnipegosis levels have fluctuated by almost nine feet, reaching their zenith in 2010. The lake is actually lower this year, but expected to rise another 10 inches by Canada Day.
Optimal level: 828 to 833.5 feet
Current level: 834.7 feet
Predicted summer peak: 835.5 feet
Record peak: 836.6 feet in 2010
3. Lake Manitoba
Officially 4,624 square kilometres, Lake Manitoba is listed as the world's 33rd-largest lake but may in fact be No. 31 as it expands to what's expected to be a record peak.
Lake Manitoba flows east into Lake Winnipeg through the Fairford River, Lake St. Martin and the Dauphin River. A dam and control structure at the source of the Fairford River has regulated the lake since 1961.
The outflow has not been able to keep pace with inflows from the Waterhen River, Whitemud River and the Portage Diversion this spring, leading to widespread inundation of ranchland along Lake Manitoba's shores, the destruction of beachfront cottages and homes and hundreds of evacuations.
Desirable level: 810.9 to 812.9 feet
Current level: 815.9 feet
Predicted summer peak: 816.5 feet
Previous record: 816.3 feet in 1955
4. Cedar Lake
Manitoba's fourth-largest lake is 1,352 square kilometres, but much of that volume stemmed from flooding induced by the construction of the Grand Rapids Generating Station at the mouth of the Saskatchewan River, which drains Cedar Lake east into Lake Winnipeg. Cedar Lake is located north of Lake Winnipegosis.
Manitoba Hydro regulates Cedar Lake by operating a spillway that opened this week, increasing outflows to Lake Winnipeg by 20,000 cubic feet per second.
Optimal level: 832 to 841 feet
Current level: 841.5 feet
Predicted summer peak: 841.6 feet
Record peak: 842 feet, most recently in 1985
5. Dauphin Lake
Located east of the city of Dauphin, 520-square-kilometre Dauphin Lake drains north to Lake Winnipegosis through the Big Mossy River. Dauphin Lake has already risen to record levels that have allowed waves to inundate Ochre Beach and other communities along its southern shore.
Desirable range: 853 to 854.8 feet
Current level: 860.4 feet
Predicted summer maximum: 861.2 feet
Previous record: 859.4 feet in 1974
Sources: Manitoba Water Stewardship and Manitoba Hydro.