Iowa DNR
Iowa DNR

ADBNet

Water Quality Assessments
Impaired Waters List

Little Rock River IA 06-BSR-1800

from confluence with Argo Slough (S17 T99N R43W Lyon Co.) to the Iowa/Minnesota state line

Assessment Cycle
2006
Result Period
2002 - 2004
Designations
Class B(LR)
Assessment Methodology
Assessment Type
Evaluated
Integrated Report
Category 1
Legacy ADBCode
IA 06-BSR-0060_3
Overall Use Support
Fully
Aquatic Life Use Support
Fully
Documentation
Assessment Comments

Assessment is based on results of IDNR/UHL ambient water quality monitoring conducted in 2002 and 2003 as part of TMDL development.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses are assessed (evaluated) as “fully supported” based on results of ambient chemical/physical water quality monitoring conducted near the Iowa/Minnesota state line by IDNR/UHL during the 2002-2004 assessment period as part of TMDL monitoring (TMDL station 1; STORET station 11720001).  

EXPLANATION:  Results of chemical/physical water quality monitoring conducted by IDNR/UHL from March 2002 through December 2003 in support of TMDL development suggest relatively good water quality in this stream.   None of the 21 samples collected had levels of dissolved oxygen, pH, or ammonia-nitrogen that violated state water quality standards (these samples were not analyzed for toxic metals or pesticides).    These results, although somewhat limited in terms of parameter coverage, suggest "full support" of the Class B(LR) aquatic life uses.

Monitoring and Methods
Assessment Key Dates
12/15/2003 Fixed Monitoring End Date
3/18/2002 Fixed Monitoring Start Date
Methods
240 Non-fixed station physical/chemical (conventional + toxicants)
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 2
Toxic 2
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A