Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Coldwater Creek IA 02-SHL-789

mouth (S29 T93N R16W Butler Co.) to confluence with unnamed tributary in S26 T94N R19W Cerro Gordo Co.

Assessment Cycle
2000
Result Period
1996 - 1998
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 02-SHL-0023_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Assessment is based on results of DNR biocriteria monitoring in July 1996: Fish IBI=34 (fair); BM-IBI=81 (excellent). See attached document for details.

Basis for Assessment

The assessment was based on data collected in 1996 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 F-IBI score was 34 (fair) and the BM-IBI score was 81 (excellent).   The aquatic life use support was assessed as fully supported / threatened (=FST), based on a comparison of the F-IBI and BM-IBI scores with biological assessment criteria established specifically for the 2000 Section 305(b) report.   The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-1998.

Monitoring and Methods
Assessment Key Dates
7/1/1996 Biological Monitoring
Methods
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
320 Benthic macroinvertebrate surveys
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 Fair
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Other habitat alterations Overall Use Support Not Impairing
  • Agriculture
  • Grazing related Sources
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
Other habitat alterations Aquatic Life Support Not Impairing
  • Agriculture
  • Grazing related Sources
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
Unionized Ammonia Overall Use Support Not Impairing
  • Agriculture
  • Intensive Animal Feeding Operations
  • Not Impairing
  • Not Impairing
Unionized Ammonia Aquatic Life Support Not Impairing
  • Agriculture
  • Intensive Animal Feeding Operations
  • Not Impairing
  • Not Impairing