Upper Iowa River and Mississippi River–Reno Watersheds Total Maximum Daily Load

The Clean Water Act (CWA), Section 303(d) requires total maximum daily loads (TMDLs) to be completed for surface waters that do not meet applicable water quality standards necessary to support their designated uses. A TMDL determines the maximum amount of a pollutant a receiving waterbody can assimilate while still achieving water quality standards and allocates allowable pollutant loads to various sources needed to meet water quality standards. This TMDL study addresses the impairments in the Upper Iowa River (UIR) and Mississippi River–Reno (MRR) watersheds in southeast Minnesota. The causes of impairment in the watershed include high levels of Escherichia coli (E. coli) and total suspended solids (TSS), affecting aquatic life, aquatic recreation, and limited resource value designated uses. Ten TMDLs are provided: nine E. coli TMDLs and one TSS TMDL.