Lake Smith IA 04-EDM-981

Assessment Comments

Assessment is based on results of (1) lake monitoring and (2) surveys by IDNR Fisheries Bureau.

Basis for Assessment

Both fishable and swimmable uses were assessed as PS for the following reasons:  (1) BPJ of DNR Fisheries; (2) results of monitoring in 1990 show that average levels of secchi depth, chl-a, total-P, and TSS are worse than the overall averages for the 116 SPOLs sampled in 1990 and 1992; average level of chl-a (150.8 mg/m3), SE=31.7) is worse than the overall average + 1 SD (77 mg/m3); (3) Bachmann et al.  (1994) report relatively low fishing pressure, but fishkills are not a problem; (4) they also report "occasional excessive blue-green algae blooms".   Low rates of erosion (estimated at 0.0 to 3.0 T/A/YR) suggest that agricultural NPS is not a major problem for this lake.   Relativey large areas of shallow depth (6' or less) probably encourage resuspension of sediment and nutrients thus leading to organic enrichment problems.