West Branch Buttrick Creek IA 04-RAC-1151

Assessment Comments

Assessment based on 1995 biocriteria data.

Basis for Assessment

Used a review of the field sheets from the 1990 and 1992 DNR stream use assessments, and the results of the 1995 DNR biocriteria sampling, to upgrade the assessment of support of theClass B(LR) aquatic life uses from FST to FS due to (1) exceptionally diverse fish community at the 1995 biocriteria site near Spring Lake Park (29 species from 6 families), (2) presence of all the expected fish taxa (11 of 11) for streams in the Des Moines Lobe subecoregion (47b), and (3) presence of several fish species (e.g., northern hogsucker, slender madtom, and several darter species) that indicate above average water quality and aquatic habitat.  Although impacts to the aquatic habitats of this stream exist, including (as identified in the previous 305(b) assessments above) row cropping, riparian pasturing, and high-flow channel scouring, these impacts have not altered the fish community beyond what is expected for a fully supporting Class B(LR) stream.   This waterbody segment is relatively long (approx.  23 miles), and if upper reaches are shown to be affected more by habitat alterations than are lower reaches (where biocriteria sampling was conducted), the waterbody should be split into subsegments.