Soap Creek IA 04-LDM-1032

Assessment Comments

1994 SUA: habscr/fshscr: 25/12 (shock; 24 species).

Basis for Assessment

Used results of the October 1994 DNR stream use assessment to assess support of the Class B(WW) aquatic life uses as FST due to (1) habitat score (25) better than the overall score (22) for DNR stream use assessments, (2) indications on field sheet of several pool/riffle sequences, only isolated channel alterations, and relatively stable stream banks with timbered riparian zone, (3) very diverse fish community for a southeastern Iowa stream (24 species, 8 families) including a good population of the state-threatened orangethroat darter (approximately 35 collected).   Also present were approximately 20 channel catfish and 2 juvenile flathead catfish.   Continued support of the aquatic life uses is threatened by hydrologic modification of headwater reaches that have amplified the flood hydrograph for this lower reach of Soap Creek.   That is, the primary impact to the reach assessed was the relatively wide and shallow channel (despite the well-vegetated (timbered) stream banks) that has resulted from scouring by high flows.  The presence of bedrock outcrops and snags are very important to the habitat quality of this reach.