Mud Creek IA 03-SSK-946

Assessment Comments

Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 1998: Fish IBI=31 (fair), BM-IBI=52 (fair).

Basis for Assessment

SUMMARY:  The general aquatic life uses remain assessed (evaluated) as "fully supported / threatened" (minor impacts) based on results of biological monitoring conducted in 1998 as part of the IDNR/UHL biocriteria project.    This assessment is the same as that developed for the 2002 reporting cycle.   The assessment type is changed from "monitored" (higher confidence assessment) to "evaluated" (relatively lower confidence assessment) due to the uncertainty of using biological assessment methods developed for Class B(LR) and wadable Class B(WW) streams to assess aquatic life conditions in general use-only stream segments.

EXPLANATION:  The aquatic life uses remain assessed as "fully supported / threatened" based on results of the IDNR/UHL biological monitoring conducted on this stream segment in 1998.   As stated in the assessment developed for the 2000 report, the F-IBI score was 31 (fair), and the BM-IBI score was 52 (fair).   The aquatic life use support status was assessed as fully supporting/threatened (=FS/T), based on a comparison of the F-IBI and BM-IBI scores 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.