It is part of the Langdon Lake subwatershed of the Minnehaha Creek Watershed District (MCWD).

The corridor between Black (also called Flanagan) and Saunders Lakes consists of wetlands and maple-basswood forest and has been identified by the Minnesota Department of Natural Resources as a regionally significant area with outstanding ecological value.

Saunders Lake scores highly on vegetative diversity, fish and wildlife habitat, and is classified in the Preserve category.

Minnehaha Creek Watershed District has graded Saunders Lake a B− for water quality on a scale of A–F.

Lakes with a B grade are defined as, “Generally good water quality but algae may limit swimming, particularly toward the end of the summer.”[1]