Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Little Maple River IA 06-LSR-1596

mouth (SW 1/4 S34 T90N R39W Ida Co.) to confluence with unnamed tributary in NE 1/4 S20 T90N R38W Buena Vista Co.

Assessment Cycle
2004
Result Period
2000 - 2002
Designations
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 1
Legacy ADBCode
IA 06-LSR-0110_0
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 1997: Fish IBI=39 (fair), BM-IBI=69 (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 1997.   This is the same assessment as that developed for the 2002 reporting cycle.

EXPLANATION:  The aquatic life uses remain assessed as "fully supported / threatened" based on results of the IDNR/UHL biocriteria monitoring conducted on this stream segment in 1997.   The F-IBI score was 39 (fair), and the BM-IBI score was 69 (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 2000 Section 305(b) report.   The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-1998.   These data are no more than five years old and, according to IDNR's methodology for Section 305(b) assessments, are thus appropriate for characterizing current water quality conditions.

Monitoring and Methods
Assessment Key Dates
8/20/1997 Biological Monitoring
8/20/1997 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
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing
  • Not Impairing