The National Weather Service has issued a hazardous weather outlook for the Lake Minnetonka area, and a flood watch for much of the region, including the Twin Cities. The area is forecast to get 2-4 inches of rain by Thursday, with pockets of five inches or more expected in some spots.
Overnight tonight, the area will likely see thunderstorms and heavy rain. According to the NWS, “These storms may become severe with large hail and damaging winds.” Thunderstorms are also expected Tuesday and Tuesday evening.
Most communities ringing Lake Minnetonka fall within the Minnehaha Creek Watershed District—a geographic area encompassing 181 square miles, including Minnehaha Creek, Lake Minnetonka, the Minneapolis Chain of Lakes and Minnehaha Falls.
The Minnehaha Creek Watershed District controls the headwaters structure at , the outlet of Lake Minnetonka to Minnehaha Creek. And according to MCWD, the discharge at Lake Minnetonka’s Grays Bay Dam was reduced to 50 cubic feet per second earlier today, in order to build capacity in Minnehaha Creek for the rainfall expected this week.
On June 20, the lake level of Lake Minnetonka (Lake Minnetonka's elevation above sea level), as measured at Minnetonka’s Grays Bay, was 929.65 feet. That’s just above the lake’s ordinary high water level of 929.40 feet. To reduce flooding on Lake Minnetonka, the MCWD tries to keep the lake level stabilized between 928.60 and 929.40 feet.
The watershed district has set up an interactive website for local residents to assess the risk of flooding to their properties.