Lower-than-normal precipitation since last October has resulted in an abnormally low water level in the Rainy River Basin, making spring flooding unlikely, according to watershed experts who met earlier this month.
While February snows helped to increase water levels, dry conditions during the winter months before reduced the risk of flooding, meteorologist Ketzel Levens of the U.S. National Weather Service (NWS) told a meeting of the International Rainy-Lake of the Woods Watershed Board Water Levels Committee (WLC).
Streamflow in the region is relatively normal, aside from outflows of Lac La Croix and Basswood, which are lower than usual, Levens told the committee, which meets to set water level recommendations for the region.
“The initial Water Levels Committee directive to [dam] operators will be to regulate outflow from the lakes in March to target April 1 water levels within the following range: 25 to 75 per cent band of the standard rule curve for Rainy Lake and the 40 to 75 per cent band of the rule curve for Namakan Lake,” the committee said in a press release following its March 10 meeting. “The WLC will monitor conditions and precipitation forecasts over the coming weeks and provide further directions for lake level regulation as needed.”
That recommendation basically says dam operators should release enough water in March to keep Rainy Lake and Namakan Lake within the middle portion of their normal spring water‑level ranges by April 1, based on each lake’s “rule curve,” a guideline for ideal seasonal water levels.
The committee will keep an eye on snowmelt, rainfall, and forecasts, and will adjust those instructions if conditions change.
Although flooding in the basin is unlikely this year, winter storms from the past couple of months have contributed to a deep freeze in the soil, which can prevent melt runoff from being absorbed into the ground properly.
Frost depth is also variable throughout the district and can amplify the snowmelt runoff. Reporting frost depths as a resident of the area helps in the general collection of data to predict flooding. Frost concerns can be reported to the Community Collaborative Rain, Hail and Snow Network on its website at https://www.cocorahs.org.
The WLC meeting was followed by a two-day virtual symposium of the Rainy-Lake of the Woods Watershed Forum, an annual online meeting that allows international scientific and land-management organizations to report findings of their research.
“We continue to see at the Forum a collective of people who live and work in this place remaining doggedly committed to maintaining and strengthening the watershed, not just as an ecosystem or scientific geography, but as a governance unit whose physical boundaries are defined by nature,” forum organizers said.
“While this may seem a natural and unremarkably practical approach to water governance, in fact it is a somewhat radical frameshift.”
