Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

North Branch North River IA 04-LDM-1106

mouth (S35 T77N R27W. Madison Co.) to confluence with unnamed tributary in S5 T77N R29W Madison Co.

Assessment Cycle
2002
Result Period
1998 - 2000
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 04-LDM-0315_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Habscrs/fshscrs=26/14, 31/12 (seine), 26/12 (shock); 1994-1997 Biocriteria: Avg. Fish IBI= 42(fair), Avg. BM-IBI= 75(good). Assessment based on 2000 biocriteria data: Fish IBI= 28 (fair), BM-IBI= 68 (good).

Basis for Assessment

The assessment was based on data collected in 2000 as part of the DNR/UHL stream biocriteria project.  The 2000 Fish IBI score was 28 (fair) and the BM-IBI score was 68 (good).  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 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
7/27/2000 Biological Monitoring
7/28/1997 Fixed Monitoring End Date
7/1/1994 Fixed Monitoring Start Date
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
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Grazing related Sources
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Range grazing - Riparian and/or Upland
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
Other habitat alterations Aquatic Life Support Not Impairing
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Grazing related Sources
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Range grazing - Riparian and/or Upland
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
Siltation Overall Use Support Not Impairing
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Grazing related Sources
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Range grazing - Riparian and/or Upland
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
Siltation Aquatic Life Support Not Impairing
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Grazing related Sources
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Range grazing - Riparian and/or Upland
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing