DES MOINES (AP) - Cities across Iowa have been pumping untreated sewage into waterways to avoid sewage backup after heavy rains, according to the Department of Natural Resources.

At least 240,000 gallons of wastewater have been diverted as of Friday afternoon, including about 156,000 gallons released from West Liberty into Wapsinonoc Creek to prevent flooding in basements.

The city of Wellsburg in Grundy County bypassed untreated wastewater from 6-8 a.m. Friday to avoid sewage backing up into basements, according to the DNR. The city bypassed at a rate of 662 gallons per minute from a lift station to an unnamed tributary of South Beaver Creek. The city has contacted a consultant to evaluate the lift station pumps.

Other sewage releases occurred in Forest City, Ainsworth and Burlington, the DNR reported. Amana Refrigeration in the Amana Colonies also had a bypass due to a clogged sewer pipe line.

The DNR released a statement Friday, saying the sewage releases are undesirable but can prevent sewage backup into homes and businesses, which can create a greater risk to human health. Bypassing to a stream can help dilute the wastewater, while sewage in basements would be undiluted, the DNR said.