|Primary outflows||To Lake Langdon|
|Basin countries||United States|
|Surface area||70 acres (28 ha)|
|Surface elevation||945 ft (288 m)|
The lake is a large, Type 5 wetland, classified as a Natural Environment lake.. The lake outlets through a small channel to Lake Langdon, which discharges through a culvert under County State-Aid Highway 110 into Lost Lake, which outlets into Cooks Bay of Lake Minnetonka. 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. Most of this area has been incorporated into Gale Woods Regional Park by the Three Rivers Park District.
The lake is considered by many to be a great crappie fishing lake, and catfish and sunfish are also present. Beavers are present as evidenced by the downed trees on its north shore.
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.”