Downs Lake

Downs Lake earns an F: 159 µg/L of phosphorus and clarity at 1.8 ft signal heavy nutrient loading from the surrounding watershed. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI above 70 puts Downs Lake in hypereutrophic territory: visible blooms are common, and clarity rarely climbs even in early summer. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Downs Lake ranks 83 of 83 in Washington County — at the lower end of the locally monitored distribution.

No invasive species are currently listed at Downs Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Downs Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Downs Lake — most use is by shoreline residents and their guests. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.