Water Quality Improvement Plans, also known by their technical name "TMDLs" (Total Maximum Daily Loads), investigate streams and lakes on Iowa's impaired waters list. The ultimate goal is to improve water quality and remove streams and lakes from the impaired list. The plans, developed by the Watershed Improvement Section of the DNR, use research results and the public's input to help reduce the amount of pollutants reaching our water.

Water quality improvement plans identify and locate water quality problems in a stream or lake, and suggest ways that communities can improve their stream or lake to meet Iowa's water quality standards.

The following plans have been approved by the US EPA: