Curfman Lake is polymictic with a maximum depth of 21 feet and comprised of 85 acres (71%) littoral surface area. The southern shoreline is heavily vegetated with both submergent and emergent aquatic vegetation. This important vegetation population allows Curfman to provide some of the nursery and spawning habitat for Detroit Lake.
Curfman Lake is connected via a natural channel on the southwest portion of Big Detroit. The lake typically mirrors that of Big Detroit and has the same average phosphorus and clarity values as its neighbor. Water quality was consistent with its average, and Big Detroit, with a 10 foot clarity and 24 ppb total phosphorus averages.
Curfman Lake is considered mesotrophic with relatively good water quality. Water quality has been stable for the last 10 years with mean phosphorus level ranging from 20ppb to 29ppb (24ppb average) and clarity levels ranging from 7.5 feet to 11 feet (average 10 feet), typically mirroring that of Big Detroit. Late summer algal blooms have been observed, typically following large rain events.
Residential developmental pressures have increase along the south shoreline with the conversion of forested land to the Golden Bay Shores planned unit development. Following the construction on the south side of the lake, approximately 25 acres (29% ) of the contributing upland drainage area consists of developed land, 17.5 acres of wetlands (20%), 35 acres (40%) of forested land, and 10 acres (11%) of grassland.
The aquatic invasive plants Flowering Rush and Curly-leaf pondweed are both present in the lake, along with invasive invertebrates Zebra Mussels and Chinese Mystery snail. The District recognizes the importance of managing nuisance invasive plant populations to promote a diverse native plant community; therefore both Flowering Rush and Curly-leaf Pondweed and assessed and management via herbicide treatments annually.