Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Big Muddy Creek IA 06-LSR-1637

mouth (S15 T96N R36W Clay Co.) to confluence with unnamed tributary in S17 T98N R35W Dickinson Co.

Assessment Cycle
2002
Result Period
1998 - 2000
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 06-LSR-0247_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

2001 Biocriteria: Fish IBI=55 (good), BM-IBI=62 (good).

Basis for Assessment

The assessment was based on the 2001 data and the aquatic life use support continued to be assessed as fully supported / threatened (=FST), based on a comparison of the F-IBI score [55 (good)] and BM-IBI score [62 (good)] 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.

Monitoring and Methods
Assessment Key Dates
9/5/2001 Biological Monitoring
9/5/2001 One-time Chemical Monitoring
Methods
320 Benthic macroinvertebrate surveys
330 Fish surveys
380 Quan. measurements of instream parms-- channel morphology-- floodplain-- 1-2 seasons-- by prof
220 Non-fixed station physical/chemical monitoring (conventional pollutant only)
315 Regional reference site approach
Monitoring Levels
Biological 4
Habitat 4
Physical Chemistry 1
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 1
BioIntegrity Good
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Other habitat alterations Overall Use Support Not Impairing
  • Agriculture
  • Removal of Riparian Vegetation
  • Not Impairing
  • Not Impairing
Other habitat alterations Aquatic Life Support Not Impairing
  • Agriculture
  • Removal of Riparian Vegetation
  • Not Impairing
  • Not Impairing
Siltation Overall Use Support Not Impairing
  • Agriculture
  • Removal of Riparian Vegetation
  • Not Impairing
  • Not Impairing
Siltation Aquatic Life Support Not Impairing
  • Agriculture
  • Removal of Riparian Vegetation
  • Not Impairing
  • Not Impairing