RIVERDALE–Lake Sakakawea experienced one of its lowest runoff totals in history in 2021, leading to declining water levels. The current level of Sakakawea is 1,828 feet, about 10 feet lower than a year ago.
Due to the low level in 2021 several boat ramps along the sprawling reservoir were either out of the water or very close to it as the boating season ended. Any further decrease in 2022 would certainly aggravate that situation in the months ahead.
It is early in the winter season, too early, to say with any certainty what the water levels in Lake Sakakawea will be this year, but the U.S. Army Corps of Engineers is closely monitoring the snowpack throughout the drainage that leads into the state’s largest reservoir.
The Corps released its initial runoff forecast for 2022 this week with a modest outlook for 21.7-million-acre feet of water to enter the drainage. That compares to the long-term average of 25.8 maf and the 2021 runoff of only 15.0 maf.
Based on early projections, which can change considerably during the winter months, the Corps says Sakakawea should rise about one foot by the end of April and peak just under 1,835 feet in late July. If that proves true, it will keep most boat ramps operational throughout the reservoir and provide for a somewhat normal recreation season on the big water.
Snowpack on the plains and in the Rocky Mountain drainage for the Missouri and Yellowstone River systems that reach Lake Sakakawea, usually peaking in July, is presently tracking a bit below normal. However, peak snow accumulation doesn’t occur until mid-April, more than three months away, and changing conditions can be expected.
The Corps measures snow water equivalent, or SWE, throughout the snowpack. It is the SWE, not necessarily snow depth, that comprises a big part of runoff projections. However, many other factors are considered in making runoff projections, such as the speed of melt and soil moisture conditions. The Corps will issue it next projected runoff for Sakakawea in early February.
