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
2006
Result Period
2002 - 2004
Designations
Class B(LR)
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 1
Legacy ADBCode
IA 04-LDM-0315_0
Overall Use Support
Fully
Aquatic Life Use Support
Fully
Documentation
Assessment Comments

Assessment is based on results of IDNR/UHL biocriteria monitoring in 2000: FIBI = 31 (fair), BMIBI = 69 (good). FIBI BIC = 36, BMIBI BIC = 51.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses are assessed (monitored) as "fully supported"  based on results of IDNR/UHL biological (biocriteria) sampling in July 2000.

EXPLANATION:  This assessment was based on data collected in 2000 as part of the DNR/UHL stream biocriteria project.  The 2000 FIBI score was 31 (fair) and the BMIBI score was 69 (good).  The aquatic life use support was assessed as fully supported (= FS),based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports.  The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004.   The FIBI BIC for this ecoregion is 36 and the BMIBI BIC for this ecoregion is 51.

Monitoring and Methods
Assessment Key Dates
7/27/2000 Biological Monitoring
7/27/2000 One-time Chemical 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 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 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