Iowa DNR

Water Quality Assessments

Impaired Waters List

Segment Summary

The Iowa DNR Water Monitoring and Assessment Section assesses waterbodies in units called segments. A segment is a portion of a river or stream, or a lake, wetland, or reservoir, where one can consider the water to be of the same quality throughout that segment.

Segment Types 2755 total segments
Number of Segments with Each Designated Use Class
Distribution of River Segment Lengths