Little Spirit Lake IA 06-LSR-1659

Assessment Comments

Monitored in 1990 and 1992 by ISU as part of the Clean Lakes Classification study (1994).

Basis for Assessment

Lake was assessed as PS (swimmable uses) & NS (fishable uses) for the following reasons: (1) BPJ of DNR Fisheries (1994); (2) monitoring in 1992 shows that average level of secchi depth is worse than typical for the 23 natural SPOLs sampled in 1990 & 1992; avg levels of total-P, chl-a, and TSS near overall avgs; (3) lake has a winterkill frequency of 17%.   Relatively low rate of sedimentation (0.3 cm/yr) suggests moderate/minor impacts from ag runoff; thus, lack of thermal stratification in this relatively shallow natural lake likely leads to relatively poor water quality that impairs uses for swimming and for aquatic life.   Assessment based primarily on BPJ of DNR Fisheries, winterkill frequency, and low secchi depth.   (DNR Fisheries considers winterkill frequency of > 1 in 7 years (= 14%) as cause for nonsupport of fishable uses.