Geode Lake IA 03-SKU-896

Assessment Comments

Assessment based on results of surveys by IDNR Fisheries Bureau and lake monitoring.

Basis for Assessment

Both were assessed as FST for the following reasons:  (1) BPJ of DNR Fisheries; (2) results of monitoring in 1990 show that average levels of secchi depth, chl-a, and TSS are better than overall averages for the 116 SPOLs sampled in 1990 and 1992.   The average level of total-P was worse than the overall mean, but was within 1 SD from the overall average; (2) lake is relatively deep (mean depth = 7.2m) and has a relatively long life expectancy (236 years) for an impoundment; (3) Bachmann et al.  (1994) report that the lake supports relatively large amounts of swimming and fishing, although filam.  alage and algal blooms interfere with swimming every few years; (4) lake does not have problems with fishkills.  Levels of fish contaminants were all < 1/2 FDA action level in 1992 but ccat continue to have rel.  high levels of PCBs.