Iowa DNR

Water Quality Assessments

Impaired Waters List

ADBNet Documentation

Outstanding Iowa Waters

Outstanding Iowa Waters (OIW) are those surface waters that Iowa DNR has classified as an outstanding state resource water. Where high quality waters constitute an outstanding state resource, such as waters of exceptional recreational or ecological significance, that water quality shall be maintained and protected.

More information about OIW-designated waterbodies and the protections afforded to them can be found at the following locations:

This page was created 9/10/2019 12:56:54 PM and was last updated 11/1/2023 2:10:37 PM