ADBNet

Assessment Comments

Basis for Assessment

Both fishable and swimmable uses were assessed as FST for the following reasons: (1) BPJ of DNR Fisheries and other staff; (2) results of monitoring show that average levels of secchi depth, total-P, chl-a, and TSS are approx.  equal to overall averages for the 86 SPO impoundments sampled in 1990 and 1992; (3) lake supports relatively high levels of fishing and swimming; (4) lake does not have winterkill problems; (5) lake has very low sedimentation rate (0.9 cm/yr) and very long life expectancy (321 years) for an Iowa impoundment.   Support of fishable/swimmable uses is threatened by excessive primary productivity that leads to summerkills in one of five years and by nuisance blooms of algae that may limit swimmable uses; both these problems may be related to lack of sufficient depth to allow the lake to thermally stratify in summer.