(IOWA CAPITAL DISPATCH) – The Iowa Department of Natural Resources released a draft version of its 2026 biennial integrated report Tuesday, which listed more than 700 segments of rivers, lakes or wetlands in the state as impaired. The list includes the Boyer River, Carter Lake, the East Nishnabotna River, the East Nodaway River, Lake Manawa, and Middle Nodaway River, to name a few.

The impaired list looks at retroactive data and determines if a water segment meets, or fails to meet, designated criteria for uses like fishing, recreation or drinking water. Once a segment is listed as impaired, it triggers a restoration process under the federal Clean Water Act.

The recent draft of the list, which is open to public comment for 30 days before it will be sent to the U.S. Environmental Protection Agency, comprises water quality data from 2022-2024 for rivers and streams and data from 2020-2024 for lakes. With each report, segments move off the impaired list or are “delisted” and other segments are added to the list. The 2026 draft report has three fewer segments listed than the report did in 2024.

In a news release about the draft, DNR said the number of impaired segments have been “relatively stable” from 2014 to 2024.  These figures do not include, however, the seven segments that EPA attempted to add to the list in late 2024  due to nitrate impairment. DNR challenged EPA’s additions to the list and the segments were removed by EPA over the summer.

The 2026 draft lists two segments of river, one on the Iowa River and one on the Raccoon River that are impaired for nitrate. DNR said it did not change its criteria from 2024 to 2026 for assessing nitrates, but the data analyzed for the newest list warranted the impairment listing.