Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Howerdon Creek IA 04-LDM-1110

mouth (S17 T76N R28W Madison Co.) to confluence with unnamed tributary in SW 1/4 S25 T76N R29W Madison Co.

Assessment Cycle
2004
Result Period
2000 - 2002
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 1
Legacy ADBCode
IA 04-LDM-0318_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Assessment based on results of IDNR/UHL biological (biocriteria) monitoring in 2001: Fish IBI= 36 (fair), BM-IBI= 70 (good).

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses are assessed (monitored) as "fully supported / threatened" (minor impacts)  based on results of IDNR/UHL biological (biocriteria) sampling in 2001.   This is the same assessment as that developed for the 2002 reporting cycle.

EXPLANATION:  This assessment was based on data collected in 2001 as part of the DNR/UHL stream biocriteria project.  The 2001 Fish IBI score was 36 (fair) and the BM-IBI score was 70 (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
7/12/2001 Biological Monitoring
7/12/2001 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
  • Channelization
  • Hydromodification
  • Not Impairing
  • Not Impairing