Just north of Turtle Mountain Provincial Park in the southwest corner of the province, Whitewater Lake is arguably one of Manitoba’s most significant Important Bird and Biodiversity Areas (IBAs). Significant because of its value to native and migratory birds, but also because it is surrounded by some of the few remaining wetlands in Manitoba. Unfortunately the wetlands of Whitewater Lake could very quickly be lost in the same way 90% of southern Manitoba’s wetlands were lost over the last century – drainage.
Whitewater Lake is truly a lake in the sense that it is a large basin of water surrounded by land, but it’s unique for a few reasons.
Whitewater is one of only a handful of endorheic lakes in Canada. Endorheic lakes are closed basin lakes, meaning they have no natural outlet. So Whitewater doesn’t flow into another body of water such as a river or creek, but only loses water via seepage or evaporation (and overland runoff from time to time).
It also fluctuates between periods of being very large (more than ten thousand hectares) to being completely bone-dry.
Like most lakes, Whitewater is surrounded by bio-rich wetlands which rely on the natural fluctuations between wet and dry periods. And because of its dry periods, there are no fish in Whitewater. That means the aquatic invertebrate species in the lake thrive - something they can't do in non-endorheic lakes. Great biodiversity of aquatic invertebrates means more biodiversity in the plant and wildlife communities that rely on them.
Because of its excellent biodiversity and importance to breeding and migratory birds, Whitewater has been designated a globally-significant Important Bird and Biodiversity Area (IBA).
It is an important breeding site for many waterbirds and shorebirds, a staging area (like a rest stop) for thousands of arctic breeding birds (including the Buff-breasted Sandpiper that breeds in the high arctic and migrates all the way to the grasslands of southern South America), the only breeding site in Manitoba for two species of Egrets, and one of the provinces hot-spots for seeing rare birds in Manitoba.
All in all about a quarter of a million birds rely on Whitewater Lake.
In May, 2016 the Government of Manitoba Environmental Approvals Branch sent out a Notice of Environmental Act Proposal (read it here) which outlined plans to construct two outlet channels from Whitewater Lake, designed to control the water levels of the lake - essentially draining the wetlands surrounding the lake to reduce flooding of areas used as agricultural land in drier years.
Nature Manitoba responded to the proposal with a letter outlining our concern. Here are a few excerpts:
Nature Manitoba would like to express our grave concern that this proposal, if enacted, could cause extreme damage to the delicate ecology of this species-rich area.
If Whitewater Lake were to be connected to the Souris River, for example, carp could be introduced, with the kind of disastrous results we have seen in many places in the province, like Delta Marsh.
Water levels at the lake must be permitted to maintain their natural cycle. The area would in fact benefit from tighter controls of drainage into the lake from nearby fields, which is part of the reason for current extreme water levels; expansion of the Wildlife Management area to encompass the highly productive ephemeral wetlands around the north of the lake; and greater promotion as a tourist attraction for watchable wildlife.
If the current proposal is enacted, when Manitoba swings back into a drought cycle, as is inevitable, the decrease in water-retention capabilities will cause hardship not just for wildlife but also for all agricultural producers in the area.
We also are concerned that the Province recently released a surface water management strategy that specifically addresses water management in terminal basins. http://gov.mb.ca/waterstewardship/questionnaires/surface_water_management/index.html. This EA application does not match the direction outlined in that strategy.
Many Manitobans are acutely aware of how significant wetlands are to our water quality. Anyone who has closely followed the story of Lake Winnipeg knows the loss of wetlands has detrimental effects which are nearly impossible to reverse. (Incidentally Whitewater Lake is also in the Lake Winnipeg watershed.)
There is also some kind of deeper loss here. Wetlands are rare, especially in southern Manitoba. And with only 9-10% of wetlands still around (many of which are damaged) what else do we lose when the last ones are altered?