Mill Creek IA 02-IOW-695

Assessment Comments

Three stream use assessments in Johnson County.

Basis for Assessment

Used results of the three November 1990 DNR stream use assessments to assess support of the Class B(LR) aqutic life uses as PS due to (1) habitat scores (19, 18, 22) relatively poor compared to the overall median score (22) for DNR stream use assessments, (2) fish community of relatively few (5) species (all cyprinids), and (3) nearly a total lack of pool development through most of the reach from the Solon WWTP down to confluence with L.  MacBride; channel is relatively wide and shallow, with shifting sand substrate.   Reasons for the poor quality aquatic habitat not readily apparent:  riparian zone is primarily timbered and in relatively good condition.  Best hypothesis is excessive erosion from agricultural land in the upper reaches of the watershed.