Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Boyer River IA 06-BOY-1511

from confluence with unnamed tributary approximately 5 miles south of Early (S 1/2 S33 T88N R37W Sac Co.) to confluence with unnamed tributary approximately 4 miles NE of Schaller in SE 1/4 SW 1/5 S5 T89N R37W Sac Co.

Assessment Cycle
2002
Result Period
1998 - 2000
Designations
Assessment Methodology
Assessment Type
Evaluated
Integrated Report
Category 0
Legacy ADBCode
IA 06-BOY-0030_3
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Documentation
Assessment Comments

Assessment is based on results of an October 1995 DNR stream use assessment.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses remain assessed as "fully supported / threatened" (minor impacts).   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 stream use 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
10/1/1995 DNR Stream Use Assessment
Methods
330 Fish surveys
375 Visual observation-- may not quantify some parameters-- single season-- by prof.
150 Monitoring data more than 5 years old
Monitoring Levels
Biological 3
Habitat 3
Physical Chemistry 0
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Other habitat alterations Overall Use Support Not Impairing
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing
Other habitat alterations Aquatic Life Support Not Impairing
  • Bank or Shoreline Modification/Destabilization
  • Channelization
  • Pasture grazing - Riparian
  • Not Impairing
  • Not Impairing
  • Not Impairing