Assessment Comments
Assessment is based on results of the November 1994 IDNR stream use assessment.
Basis for Assessment
SUMMARY: The Class B(LR) aquatic life uses remain assessed as "partially supported" based on results of biological monitoring and a habitat survey conducted as part of a 1994 IDNR stream use assessment. The assessment category, however, is changed from "monitored" to "evaluated" due to the age of this information.
EXPLANATION: Continue to use the assessment developed for the 1998 report that was based on results of the 1994 IDNR stream use assessment. As stated in the assessment developed for the 1998 reporting cycle, the field sheets from the June 1992 and November 1994 stream use assessments show (1) relatively poor to moderately diverse fish communities (species/families, 1992->1994: 6/1; 10/3) for streams in the Iowan Surface subecoregion (47c), (2) presence of a slight majority of the expected fish taxa (6 of 11 and 7 of 11) for streams in this subregion, with none of the catfishes or sunfishes represented. These results suggested only "partial support" of the Class B(LR) aquatic life uses. Because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is changed from "monitored" (indicating an assessment with relatively high confidence) to "evaluated" (indicating an assessment with relatively low confidence). As stated in the assessments developed for the 1998 and 2000 reports, follow-up monitoring is needed in this stream reach to determine the status of aquatic communities and habitats and to determine the degree to which the Class B(LR) uses may be impaired.
