Officials are advising people not to swim or do any other water-related activities in Lake Minnetonka and two other nearby lakes because untreated sewage will likely flow into the lakes.
The Minnesota Pollution Control Agency said in a news release that heavy rain over the weekend forced the city of Mound to release raw sewage into the stormwater sewer system on Sunday. The city did this to prevent waste water from backing up into the basements of about 1,000 homes.
The city released the untreated wastewater onto the land at four sites near Lake Minnetonka: the lagoon at Emerald Road and Channel Lane, Beachside outfall at Shorewood, the Avalon Park outfall at Bartlett Boulevard and Lynwood at Morton Channel.
The wastewater was also released at Cottonwood and Lynwood on Lake Langdon and the Grandview boat launch on Dutch Lake.
Officials said the sewage will likely make its way into these lakes. Even though the wastewater will be diluted, it will increase the lakes' E. coli bacteria, which can make people sick, pollution officials say.
E. coli can cause gastrointestinal illnesses, such as severe diarrhea, nausea and possibly jaundice as well as associated headaches and fatigue, according to the Minnesota Department of Health.
This weekend's heavy rain caused flooding around Minnehaha Creek, which is fed by Lake Minnetonka. Both the creek and lake set records for high water levels over the weekend.
Lake Minnetonka's water level was at 930.64 feet above sea level Monday morning, which was an increase of 5.16 inches since Friday – setting a new all-time high record for the lake, the Minnehaha Creek Watershed District said on its Facebook page.
Lake Minnetonka's high water levels this spring have already limited recreational activities on the lake. For most of May, the Lake Minnetonka Conservation District has had to impose speed limits on the majority of the lake to limit shoreline erosion. Boaters were limited to 5 mph for 17 of the lakes bays, FOX 9 reports.