Bays Branch IA 04-RAC-1193

Assessment Comments

Assessment remains based on information from the IDNR Wildlife Bureau.

Basis for Assessment

SUMMARY:  Continue to assess (evaluate) support of the Class B(LW) aquatic life uses as "partially supported" based on information from the IDNR Wildlife Bureau.   Fish consumption uses remain "not assessed."  This assessment is the same as that developed for previous assessment/listing cycles.  

EXPLANATION:  The previous (2000) assessment of support of the Class B(LW) uses ("partially supported") was reviewed and approved by the DNR Wildlife Bureau in 2002.   According to the local DNR Wildlife Biologist, this wetland remains impaired by siltation from agricultural nonpoint sources.   The following beneficial uses are impacted by this siltation problem:  water storage capacity of the impoundment; water quality, game fish populations, recreational fishing, boating recreation, and waterfowl hunting.    The assessment category for this wetland of "evaluated" indicates that the assessment is based entirely on "best professional judgment."  In terms of Section 305(b) reporting, "monitored assessments" are based primarily on recent, site-specific ambient monitoring data and thus have relatively high confidence.   IDNR considers waterbodies identified as "impaired" based on "monitored assessments" as candidates for the state's Section 303(d) list.   "Evaluated assessments" are those based on data older than five years or other than site-specific ambient monitoring data (e.g., questionnaire surveys of fish and game biologists [=best professional judgment]) and thus have relatively lower confidence.   IDNR does not consider waterbodies identified as "impaired" based on "evaluated assessments" as candidates for the state's Section 303(d) list.  

Fish consumption uses remain "not assessed."  In general, Iowa wetlands are not managed for recreational fisheries; thus, fish contaminant monitoring is not typically conducted at these waterbodies.