Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

North Raccoon River IA 04-RAC-1139

from County Road M54 (S24T88N R36W Sac Co.) to confluence with Drainage Ditch 101 in S36 T91N R36W Buena Vista Co.

Assessment Cycle
2004
Result Period
2000 - 2002
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 2a
Legacy ADBCode
IA 04-RAC-0050_2
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Fish Consumption
Not assessed
Documentation
Assessment Comments

Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 1998: Fish IBI= 56 (good), BM-IBI= 60 (good).

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses are assessed (monitored) as "fully supported / threatened" (minor impacts)  based on results of IDNR/UHL biological (biocriteria) sampling in 1998.   Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this stream segment.   This is the same assessment as that developed for the 2002 reporting cycle.

EXPLANATION:  The assessment was based on the 1998 biological assessment data, and the aquatic life use support continued to be assessed as fully supporting / 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 F-IBI score was 56 (good) and the BM-IBI score was 60 (good).   See assessment developed for the 2000 reporting cycle for more information.

Monitoring and Methods
Assessment Key Dates
10/8/1998 Biological Monitoring
10/8/1998 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 Good
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Other habitat alterations Aquatic Life Support Not Impairing
  • Channelization
  • Not Impairing