Iowa DNR

Water Quality Assessments

Impaired Waters List

Maple River IA 06-LSR-1581

mouth (S17, T83N, R44W, Monona Co.) to confluence with unnamed tributary approximately 1 mile east of Danbury in SW 1/4, NE 1/4, S26, T86N, R42W, Woodbury Co.

Assessment Cycle
Release Status
Result Period
1992 - 1994
Assessment Type
Integrated Report
Category 0
Legacy ADBCode
IA 06-LSR-0070_1
Overall Use Support
Aquatic Life Use Support
Fish Consumption
Not assessed
Assessment Comments

Assessment is based on results of IDNR ambient quarterly monitoring near Mapleton and an IDNR stream use assessment conducted downstream from Ida Grove in October 1995.

Basis for Assessment

Used assessment of support of aquatic life uses developed for the 1994 report (PS) along with results of DNR stream use assessment conducted downstream from Ida Grove in Oct 1995.   Results of stream assessment supports the previous assessment as PS due to (1) extensive channelization and (2) excessive stream bank erosion in reaches not yet channelized.  Assessment found very little for pool habitat even in the areas that remain meandered.   Fish community at sampling site contains the expected species, but numbers of individuals per species, especially for larger fish, was relatively low.

Monitoring and Methods
Assessment Key Dates
230 Fixed station physical/chemical (conventional plus toxic pollutants)
330 Fish surveys
375 Visual observation-- may not quantify some parameters-- single season-- by prof.
Monitoring Levels
Biological 3
Habitat 3
Physical Chemistry 3
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