Assessment Comments
Assessment based on 2003 biocriteria data: FIBI = 20 (poor); FIBI BIC = 33.
Basis for Assessment
[Note: Prior to the current (2008) Section 305(b) cycle, this stream segment was designated only for Class B(LR) 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 now presumptively designated for Class A1 (primary contact recreation) uses. The stream remains designated for aquatic life uses (now termed Class B(WW2) aquatic life uses). Thus, for the current (2008) assessment, the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW2) water quality criteria.]
SUMMARY: The presumptive Class A1 (primary contact recreation) uses are "not assessed" due to the lack of information upon which to base an assessment. The support level of the Class B(WW2) aquatic life uses changed to "partially supported" (minor impacts) based on results of biological monitoring conducted as part of the IDNR/UHL stream biocriteria project.
EXPLANATION: The assessment of the Class B(WW2) aquatic life uses was based on data collected in 2003 as part of the DNR/UHL stream biocriteria project. The 2003 FIBI score was 20 (poor) and the BMIBI score was not calculated due to the severe low number of organisms collected during the sampling. The aquatic life use support was assessed (evaluated) as Partially Supporting (=PS), based on a comparison of the FIBI score with biological impairment criteria (BIC) established for previous Section 305(b) reports. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004. The FIBI BIC for this ecoregion is 33.
This assessment was categorized as "evaluated" because of the sampling conditions in 2003. This site is a reference site for the 40a ecoregion and has historically been assessed as "fully supporting". During the 2003 sampling visit, a bankfull/out of bank flood event less than one week prior, and was documented as a reason for the overall low aquatic abundance. From the 2003 Lick Creek field sheets: "Poor catch may be related to high (overbank) flow about a week prior to sampling. High (overbank) flows had occurred about a week prior to sampling. Much of the rock was clean (scoured & redeposited). Colonization was light in all habitats." This reference site will be sampled again in the near future.
