Iowa DNR
Iowa DNR

ADBNet

Water Quality Assessments
Impaired Waters List

Bear Creek IA 02-IOW-702

from confluence with L. Bear Cr. (S16 T80N R13W Poweshiek Co.) to confluence with unnamed tributary in SW 1/4 S9 T80N R14W Poweshiek Co.

Assessment Cycle
2006
Result Period
2002 - 2004
Designations
Class B(LR)
Assessment Methodology
Assessment Type
Monitored
Integrated Report
Category 5b
Legacy ADBCode
IA 02-IOW-0180_2
Overall Use Support
Partial
Aquatic Life Use Support
Partial
Documentation
Assessment Comments

Assessment based on results of IDNR/UHL biological (REMAP) monitoring in 2002: FIBI = 23 (poor), BMIBI = 38 (fair). FIBI BIC = 36, BMIBI BIC = 51.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses are assessed (monitored) as "partially supported" based on results of IDNR/UHL biological (REMAP) sampling in 2002.  

EXPLANATION:  This assessment was based on data collected in 2002 as part of the DNR/UHL REMAP project.   A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data.   The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach.   The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI).   The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum).   The 2002 FIBI score was 23 (poor) and the BMIBI score was 38 (fair).  The aquatic life use support was assessed as partially supporting (= PS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports.  The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004.   The FIBI BIC for this ecoregion is 36 and the BMIBI BIC for this ecoregion is 51.

Monitoring and Methods
Assessment Key Dates
9/25/2002 Biological Monitoring
9/25/2002 One-time Chemical 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
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
Cause Unknown Aquatic Life Support Moderate
  • Source Unknown
  • Moderate