Willow Lake IA 06-BOY-1612

Assessment Comments

Monitored in 1990 by ISU as part of Clean Lakes Classification Study (1994).

Basis for Assessment

Both were assessed as FST for the following reasons:  (1) results of monitoring in 1990 show that averages of secchi depth, total-P, chl-a, and TSS are approximately equal to, or better than, overall averages for the 116 SPOLs sampled in 1990 and 1992; (2) according to Bachmann et al.  (1994) the lake as a relatively low sedimetation rate (2.5 cm/yr) and a relatively long life expectancy for an impoundment (145 years); (3) lake is relatively deep (mean depth = 3.7m), does not have problems with fishkills, and supports both fishing and swimming.   Support of uses is slightly threatened by sediment in ag NPS runoff; otherwise, physical and chemical features of this lake are well above average for SPO impoundments in SW Iowa.