Lake Wahtopanah, also known as Rivers Reservoir, is a
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
on the
Little Saskatchewan River
The Little Saskatchewan River is a river in western Manitoba. It originates in Riding Mountain National Park at Lake Audy and flows about south through the communities of Minnedosa and Rapid City. Its approximate length is 185 km. It jo ...
near the town of
Rivers, Manitoba
Rivers is an unincorporated urban community in the Riverdale Municipality within the Canadian province of Manitoba. It is located northwest of Brandon, above sea level. It is within the Westman Region (Southwestern Manitoba). Agriculture, health ...
. Its dam was built by the
Prairie Farm Rehabilitation Administration The Prairie Farm Rehabilitation Administration (PFRA) was a branch under Agriculture and Agri-Food Canada (AAFC), a department of the Federal Government of Canada.
The Prairie Farm Rehabilitation Administration was established by an Act of Parliam ...
in 1960 to supplement water supplies for
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
. It also provides the water supply for the town of Rivers, stock watering and recreation. The
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
is about wide and six miles (10 km) long. The deepest point is about . Riparian flows are regulated by a four-foot square gated conduit. High flows pass over a wide concrete chute spillway. The reservoir stores about and covers an area of about . The drainage area is about and extends well into
Riding Mountain National Park
Riding Mountain National Park is a national park in Manitoba, Canada. The park is located within Treaty 2 Territory and sits atop the Manitoba Escarpment. Consisting of a protected area , the forested parkland stands in sharp contrast to the sur ...
. The province maintains a park and campground on the west shore.
The name is an alternate form of the Native word watopapinah meaning "canoe people".
In late June and early July 2020, the area received a 1 in 1000 year runoff event; the flow peaked at about 300 cms (10600 cfs) . The area received over 20 inches of rain over a 5-day period causing the lake to flood to the never before seen level of 471.02 meters (1545.35 feet above sea level), 2.85 meters (9.35 feet) above the full supply level. This also caused the Manitoba Government to lose confidence in the dam and to warn everyone down stream of the likelihood of dam failure and catastrophic flooding. It caused nearby municipalities and the City of Brandon to declare states of emergency and the City of Brandon to put over 2000 residents on evacuation notice. Several near by cabins, homes, and campers in seasonal campground were lost.
Once the flood waters receded, the province was able to assess the dam and regain confidence in the structure.
References
{{DEFAULTSORT:Wahtopanah
Lakes of Manitoba
Reservoirs in Canada