ADBNet

Assessment Comments

Assessment based on occurrence of fishkills.

Basis for Assessment

The Class B(LR) aquatic life uses remained assessed as "fully supported / threatened."  EXPLANATION:  Continue to use the previous assessment of support of the Class B(LR) uses developed for the 1998 report (see above).   This assessment was based on (1) results of three fish surveys conducted by Iowa State University in 1995 and (2) occurrence of fish kills in August 1996 and July 1998 in the upstream reach of Tipton Creek (IA 02-IOW-0300-2).   The 1998 assessment was also based on the results of a DNR stream use assessment in May 1992.   The results of this stream assessment, however, are greater than five years old and are thus considered too old to be useful for assessing current water quality conditions.   Although no fish kills have been reported for Tipton Creek since the kill on the upper segment in July 1998, the potential for additional kills in this fishkill-plagued watershed suggests a continuing threat to the full support of the Class B(LR) aquatic life uses.   As stated above, the lower reach of Tipton Creek has historically demonstrated high quality aquatic habitats and exceptional diversity of aquatic life for an Iowa stream.   In the absence of impacts from fishkills, this stream reach would likely "fully support" its aquatic life uses.