Shields Lake is a shallow lake of 30 acres with at 87% of its area in the littoral zone where rooted plants can grow. It's used mainly for fishing and has a public fishing pier. It drains 538 acres with most of that lying to the south of the lake. Shields Lake drains to Forest Lake. The lake was placed on the State's Impaired Waters List in 2006 due to high nutrient levels. It currently has a lake grade of C-. Shields Lake has been the focus of a number of past lake improvement efforts including aeration, fish stocking, fish barrier installation, chemical rehabilitation, and alum treatment. The lake's current management includes an aeration system and a fish barrier on the outflow stream to Forest Lake. In 2007, trumpeter swans were noted to be nesting on the lake.