Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

West Tarkio Creek IA 05-TAR-1497

from the Iowa/Missouri state line to confluence with an unnamed tributary in S9 T69N R38W Page Co.

Assessment Cycle
2002
Result Period
1998 - 2000
Designations
Assessment Methodology
Assessment Type
Evaluated
Integrated Report
Category 0
Legacy ADBCode
IA 05-TAR-0020_0
Overall Use Support
Partial
Aquatic Life Use Support
Partial
Documentation
Assessment Comments

Assessment is based on results of 1995 Biocriteria sampling: Fish IBI=30 (fair), BM-IBI= 39(fair).

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses remain assessed as "partially supported."  The assessment category, however, is changed from "monitored" to "evaluated."  EXPLANATION:  Continue to use the assessment developed for the 1998 and 2000 reports (see above) that was based on results of the 1995 IDNR biocriteria assessment.   However, because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is changed from "monitored" (indicating an assessment with relatively high confidence) to "evaluated" (indicating an assessment with relatively low confidence).

Monitoring and Methods
Assessment Key Dates
10/12/1995 Biological Monitoring
Methods
220 Non-fixed station physical/chemical monitoring (conventional pollutant only)
315 Regional reference site approach
320 Benthic macroinvertebrate surveys
330 Fish surveys
380 Quan. measurements of instream parms-- channel morphology-- floodplain-- 1-2 seasons-- by prof
150 Monitoring data more than 5 years old
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 Overall Use Support Moderate
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Slight
  • Slight
  • Moderate
  • Slight
  • Moderate
Other habitat alterations Aquatic Life Support Moderate
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Slight
  • Slight
  • Moderate
  • Slight
  • Moderate
Siltation Overall Use Support Moderate
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Slight
  • Slight
  • Moderate
  • Slight
  • Moderate
Siltation Aquatic Life Support Moderate
  • Agriculture
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Habitat Modification (other than Hydromodification)
  • Hydromodification
  • Slight
  • Slight
  • Moderate
  • Slight
  • Moderate