Maple River IA 06-LSR-1581

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.