Why can’t you swim in the lake? Would it pose any health risk or danger?

I've always heard a rumor of an undertow in that Lake is that even a real thing?

The Township does not provide life guards, so they must post signs. The lake has no inlet/outlet, and is fed entirely by groundwater. The Nature Reserve committee has tested the lake for bacteria in the past, which is a typical approach for a swimming area. All tests passed without issue. However tests are not performed on a regular basis. There is a sizeable bird population year round, so the bacteria levels are sure to change with the number of birds, water temperature, etc. Non-motorized boats, paddle boards, etc. are allowed on the lake with appropriate life jacket use.