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Assessment Comments

Assessment remains based on the May 2006 summary of trout reproduction in Iowa streams as prepared by the IDNR Fisheries Bureau.

Basis for Assessment

Note:  Prior to the 2008 Section 305(b) cycle, this stream segment was classified only for general 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 and for Class B(WW1) aquatic life uses.   According to the Iowa Water Quality Standards, all perennial rivers and streams and all intermittent streams with perennial pools that are not specifically listed in the Iowa surface water classification are designated as Class A1 and Class B(WW1) waters.   Thus, for the current (2010) assessment, perennial flow is presumed, and the available water quality monitoring data will be compared to the applicable Class A1 and Class B(WW1) 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 presumptive  aquatic life uses are assessed (monitored) as "fully supported" based on the May 2006 summary of trout reproduction in Iowa streams as prepared by the IDNR Fisheries Bureau.   Although not designated for coldwater aquatic life uses in the March 2006 version of the Iowa Water Quality Standards, this stream is considered a trout stream by the IDNR Fisheries Bureau.    Thus, this assessment segment is being assessed as a coldwater stream for the 2010 Integrated Reporting cycle.    

Based on an updated summary of trout reproduction in Iowa streams prepared by the DNR Fisheries Bureau in May 2006, the presumptive aquatic life uses are assessed as "fully supported".   According to the updated summary, Duck Creek is in the group of Iowa coldwater streams that supports natural reproduction of trout.   Based on results of surveys by the IDNR Fisheries Bureau, this stream is placed in the category of Iowa trout Streams that exhibit fairly consistent natural reproduction and maintain a viable population of the listed species without any stocking.