Sny Magill Creek IA 01-YEL-430

Assessment Comments

Assessment is based on (1) results of at Sny Magill project sites monitored for water quality at varying frequencies in 2000-01 and (2) a 2002 DNR summary of trout reproduction.

Basis for Assessment

SUMMARY:  The Class B(CW) coldwater aquatic life uses are assessed (monitored)  as "fully supported."  Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this coldwater stream.   Sources of data for this assessment include (1) an updated summary of trout reproduction in Iowa streams prepared by the DNR Fisheries Bureau in April 2002 and (2) results of water quality monitoring conducted from January 2000 through September 2001 at three sites on Sny Magill Creek:  Site 1 (IDNR station 15220004), Site 2 (IDNR station 15220005), Site 3 (IDNR station 15220002).

EXPLANATION:  Based on the updated summary of trout reproduction in Iowa streams prepared by the DNR Fisheries Bureau in April 2002, the Class B(CW) uses remain assessed as "fully supported" (see assessment for the 2002 report).   According to this summary, this reach of Sny Magill Creek is in the category of Iowa trout streams that have fairly consistent natural reproduction and are capable of maintaining a viable population for the target trout species without any stocking.   This assessment is supported by results of chemical water quality monitoring conducted from 1996 through 1999 (see assessment for the 2000 report).   Fish consumption uses remain "not assessed" due to lack of fish tissue monitoring in this stream reach.   Monitoring of chemical water quality, habitat quality, fish populations, and aquatic macroinvertebrate populations has been conducted at Sny Magill Creek since 1992 as part of the Sny Magill Creek Nonpoint Source Pollution Monitoring Project.   Results of this monitoring show good chemical water quality and aquatic life.  

The Class B(WW) aquatic life uses were also assessed as "fully supported" based on results of water quality monitoring at three monitoring sites on Sny Magill Creek.   Of the approximately 200 samples analyzed at these stations, no samples violated the respective Class B(CW) water quality criteria for dissolved oxygen and temperature.  

Fish consumption uses remain "not assessed" due to lack of fish tissue monitoring in this stream reach.