Slip Bluff Lake IA 05-GRA-1362

Assessment Comments

Basis for Assessment

Lake was assessed as PS for the following reason: lake has long periods of turbid water due to suspended clays (Bachmann et al.  1994).  Based on results of monitoring in 1990, however, lake appears to have relatively good water quality; e.g., mean levels of secchi depth, chl-a, total-P, and TSS are within the range of the overall means of the 116 SPOLs sampled in 1990 and 1992 +/- 1 SD.   Although designated for swimmable uses, the lake does not have a swimming beach, and Bachmann et al.  report swimming use as zero; thus, swimmable use not assessed.   Lake has typical sedimentation rate (2.5 cm/yr) and better than typical life expectancy for a SPO impoundment.   In addition, only 38% of the WS is in cropland.   Thus, high periods of turbidity is likely due to unusual soil type or to nuisance fish species.  DNR fishing forecast for 94 notes crappie and CCAT for this lake.