MINNEAPOLIS (WCCO) — Both Monday and Tuesday were perfect days to be out on the lake, but several Twin Cities lakes remained closed due to unsafe levels of E. coli.

Swimmers are being told to avoid Excelsior Beach on Lake Minnetonka and the swimming beach on McCarrons Lake in Roseville. The city of Minneapolis also closed three beaches to prevent people from getting sick, including Lake Hiawatha Beach and two Bde Maka Ska beaches– Thomas Beach and 32nd Street Beach.

E.Coli levels have been too high for the past two weeks.

Crews from Hennepin County Health were out testing the water on the closed beaches on Monday.

We’ve learned that the cause of these elevated E. coli levels was likely all that rain we got the last few weeks. The Minneapolis Parks Board says the storm water contains E. coli from animals and people.

There was a lot of talk about Lake Minnetonka as a whole after 170 people became ill after spending the 4th of July on Big Island, but that was determined not to be related to E. coli.

The park board did say if we get a dry stretch it’s possible a couple of the beaches will open up next week, but will still need to be tested before that happens.

Kate Raddatz