Cedar Creek IA 04-RAC-1819

Assessment Comments

2001 Biocriteria: Fish IBI= 48(fair), BM-IBI= 46(fair).

Basis for Assessment

Cedar Creek was is classified as a "general use" waterbody upstream from its confluence with Little Cedar Creek.   No assessment information is available; thus, this reach of Cedar Creek was not assessed for either the 1996, 1998, or 2000 reports.      
[NOTE:  For the 2002 report, the previous waterbody segment for Cedar Creek (IA 04-RAC-0160-0), which extended 28.23 miles from its confluence with Little Cedar Creek (Pocahontas Co.) to its headwaters in Pocahontas County, was split into two subsegments:  (1) Little Cedar Creek to Drainage Ditch 21 (IA 04-RAC-0160-1) and (2) from Drainage Ditch 21 to headwaters in Pocahontas Co.  (IA 04-RAC-0160-2).   See above for previous Section 305(b) assessments for the original 28.23-mile river segment of Cedar Creek.]

The assessment was based on data collected in September 2001 on Big Cedar Creek approximately 7 mile NNE of Fonda in Pocahontas County as part of the DNR/UHL stream biocriteria project.   A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data.   The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach.   The biological metrics were combined to make a fish community index of biotic integrity (F-IBI) and a benthic macroinvertebrate index (BM-IBI).   The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum).

The 2001 Fish IBI scores was 48(fair) and the BM-IBI scores was 46(fair).  The aquatic life use support was assessed as partially supporting (=PS), based on a comparison of the F-IBI and BM-IBI scores with biological assessment criteria established specifically for the 2002 Section 305(b) report.  The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2001.