Heather Branch IA 03-SKU-901

Assessment Comments

Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 1998: Fish IBI= 58 (good).

Basis for Assessment

SUMMARY:  The general aquatic life uses remain assessed (evaluated) as "fully supported" based on results of IDNR/UHL biological monitoring in 1998.   The assessment type is considered "evaluated" (relatively lower confidence assessment) due to (1) the uncertainty of using biological assessment methods developed for Class B(LR) and wadable Class B(WW) streams for assessing aquatic life conditions in general use-only stream segments and (2) the sampling for only one (fish) of the two indicator communities (fish and aquatic macroinvertebrates) typically sampled as part of IDNR/UHL biocriteria monitoring.  

EXPLANATION:  The aquatic life uses remain assessed as "fully supported" based on results of the IDNR/UHL biological monitoring conducted on this stream segment in 1998.   As stated in the assessment for the 2000 reporting cycle, only fish data were collected and analyzed; the F-IBI score was 58 (good).   The aquatic life use support status was assessed as fully supporting (=FS), based on a comparison of the F-IBI with biological assessment criteria established specifically for the 2000 Section 305b report (IDNR 2000).   The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-1998.   These data are less than five years old and, according to IDNR's methodology for Section 305(b) assessments, are thus appropriate for characterizing current water quality conditions.