Iowa DNR investigates a manure fish kill on a Little Maquoketa tributary

A fish kill is under investigation on the Little Maquoketa River near Peosta. The Iowa Department of Natural Resources said Oct. 2, 2026, that its Manchester field office was notified Oct. 1 of a possible manure release and fish kill in an unnamed tributary north of Peosta, in Dubuque County.

Staff found dead fish and murky water. They identified manure runoff from a nearby animal feeding operation as the source. The amount released was still unknown. Cleanup had started, the responsible party had been notified, and that party was working to control the runoff. The case remains open.

The department is telling downstream water users to avoid using water from the Little Maquoketa River for now. Anyone who sees dead or stressed fish should call the DNR’s 24-hour spill line at 515-725-8694. The release says a fast report can help staff find the cause and, in some cases, stop a kill that is still underway.

This is a The Gillnet news desk summary, not a reprint.

Source: Iowa DNR — DNR investigating fish kill at Little Maquoketa River in Dubuque County (Oct. 2, 2026).