Iowa DNR
ADBNet

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
1998
Release Status
Final
Result Period
1994 - 1996
Designations
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 06-LSR-0070_1
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Fish Consumption
Not assessed
Documentation
Assessment Comments

Assessment based on results of IDNR stream use assessment conducted downstream from Ida Grove in October 1995 and the results of the August 1997 DNR watershed bioassessment conducted 1/8th mile downstream from the Ida Grove WWTP.

Basis for Assessment

Upgraded the assessment of support of the Class B(WW) uses as FST due to a review of the field sheet from the October 1995 DNR stream use assessment that shows a very diverse fish community for western Iowa (17 spp; 5 fams) that contains species expected for streams in this region plus game fish (channel catfish) that justify the Class B(WW) use designation.   Thus despite threats to continued support, including extensive alterations of the channel, including channel straightening, removal of riparian vegetation (especially mature trees) and streambank erosion, the composition of the fish community suggests that the Class B(WW) aquatic life uses are fully supported.   Results of the August 1997 DNR watershed bioassessment conducted 1/8th mile dstr from the Ida Grove WWTP supports the assessment of the Class B(WW) aquatic life uses as FST due to (1) presence a very diverse fish community for the Loess Hills and Rolling Prairies subecoregion, 14 spp, 5 fams), (2) presence of majority (4 of 7) of expected fish taxa for streams in the Loess Hills and Rolling Prairies subecoregion, (3) presence of the expected game fish species (channel catfish), and (4) lack of violations of Class B(WW) aquatic life criteria in the sample collected during the watershed bioassessment.

Monitoring and Methods
Assessment Key Dates
Methods
330 Fish surveys
380 Quan. measurements of instream parms-- channel morphology-- floodplain-- 1-2 seasons-- by prof
315 Regional reference site approach
320 Benthic macroinvertebrate surveys
220 Non-fixed station physical/chemical monitoring (conventional pollutant only)
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