Assessment Comments
Assessment based on 2001 IDNR/UHL biocriteria sampling data: 0/4 coldwater biological indicators met the criteria - Not Supporting (NS).
Basis for Assessment
[Note: Prior to the current (2008) Section 305(b) cycle, this stream segment was designated only for Class B(CW) aquatic life uses. Due to changes in Iowa’s surface water classification that were approved by U.S. EPA in February 2008 (see http://www.iowadnr.com/water/standards/files/06mar_swc.pdf), this segment is also now presumptively designated for Class A1 (primary contact recreation) and Class A2 (secondary contact recreation) uses. This segment remains designated for coldwater aquatic life use (now termed Class B(CW1) uses), and for fish consumption uses (now termed Class HH (human health/fish consumption) uses. This stream segment also remains identified as an “HQR” (high quality resource) water.]
SUMMARY: The presumptive Class A1 (primary contact recreation) uses and the presumptive Class A2 (secondary contact recreation) uses are "not assessed" due to the lack of information upon which to base an assessment. The Class B(CW1) coldwater aquatic life uses are assessed (evaluated) as "not supported" based on results of biological monitoring in 2001. The 2001 data used for the Class B(CW) coldwater aquatic life assessment are now more than five years old; therefore, this assessment is considered "evaluated" instead of "monitored". Fish consumption uses are not assessed due to the lack of fish contaminant monitoring in this assessment segment.
EXPLANATION: The assessment of the Class B(CW1) aquatic life uses was based on data collected in 2001 as part of the DNR/UHL stream biocriteria project. A series of four (4) coldwater biological indicators, which reflect stream water quality and habitat integrity, were calculated from the biocriteria sampling data. The coldwater biological indicators are based on the numbers and types of coldwater benthic macroinvertebrate taxa that were collected the stream sampling reach. Sites that do not receive any type of trout stocking are scored on the benthic macroinvertebrate data only. Non-trout stocking sites that score 3 or 4 are Fully Supporting (FS), sites that score 1 or 2 are Partially Supporting (PS), and sites that score 0 are Not Supporting (NS). The 2001 biocriteria coldwater biological indicator score was 0/4. The aquatic life use support was assessed (evaluated) as Not Supporting (=NS), based on a comparison of the coldwater biological indicator score with biological assessment criteria established for this Section 305(b) report. The coldwater biological indicators were determined from a statistical analysis of data collected at coldwater stream ecoregion reference sites from 1994-2004 and with assistance from the IDNR Fisheries Bureau.
