DNR Investigating Fish Kill After Manure Runoff Near Peosta

The Iowa Department of Natural Resources is investigating a fish kill along the Little Maquoketa River, after a manure runoff was discovered in a nearby tributary.

Get our free mobile app

DNR officials were notified Thursday, October 1st, of a possible manure release north of Peosta in Dubuque County. When staff from the Manchester Field Office arrived, they found dead fish and murky water in the tributary. Investigators identified runoff from a nearby animal feeding operation as the source. The amount released is currently unknown.

Cleanup efforts are currently underway. The DNR has stated the responsible party has been notified and is working to control the runoff. Downstream water users are being advised to avoid using water from the Little Maquoketa River while the investigation continues.

Credit: Google Maps | The Little Maquoketa River and it's tributaries near Peosta.

Manure runoff can create problems beyond the immediate and obvious fish deaths. Excess nutrients like nitrogen and phosphorus can contribute to algae growth. Organic waste can also reduce the dissolved oxygen levels that fish and other aquatic life need to survive. Depending on the conditions, runoff can even introduce harmful bacteria and affect water quality downstream. Stopping the source of a manure release early can help limit how far contamination travels. This reduces additional damage to aquatic life and make cleanup efforts more manageable.

This is not the first manure-related incident documented in the area. Iowa DNR records show a May 2024 discharge from a dairy cattle operation into an unnamed tributary of the Little Maquoketa River. Officials have not indicated that this previous incident was connected to the current runoff situation. In the 2024 case, a fine of $1260 was given to the offender. They were also told to, "develop a Plan of Action detailing how open feedlot runoff and manure solids will be contained." Additionally, anyone who spots dead or distressed fish in a local water source should contact the DNR's 24-hour spill line at 515-725-8694.