Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Mill Creek IA 06-LSR-1615

mouth (S14 T92N R40W Cherokee Co.) to confluence with Whisky Cr. at east line S29 T94N R41W O'Brien Co.

Assessment Cycle
2000
Result Period
1996 - 1998
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 06-LSR-0170_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Assessment is based on results of a DNR/UHL biocriteria sampling in 1998 (Fish IBI=43 (fair), BM-IBI=75 (good)).

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses were assessed as "fully supported / threatened."  EXPLANATION:  The primary basis for the previous assessment of the Class B(LR) uses was the DNR fish survey from June 1989.   Results from this survey are now too old (greater than five years) for developing an assessment of current water quality conditions.   The current assessment is based on results on a 1998 DNR/UHL biocriteria sampling of fish and benthic macroinvertebrates.   Based on a comparison to results of ecoregion reference site sampling, the fish community was rated fair (Fish IBI=43), and the macroinvertebrate community was rated good (MB IBI=75),  These results suggest that the aquatic life uses are "fully supported / threatened."

Monitoring and Methods
Assessment Key Dates
10/7/1998 Biological 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
  • Channelization
  • Grazing related Sources
  • Hydromodification
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
Other habitat alterations Aquatic Life Support Not Impairing
  • Agriculture
  • Channelization
  • Grazing related Sources
  • Hydromodification
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing