Heavy rain will start as early as Friday morning in some spots and continue through Saturday, according to WHIO-TV meteorologist Rich Wirdzek.

"Most of the flooding will start near the end of the storm system Saturday and then continue for a couple of days after that," Wirdzek said.

Thursday will be dry and sunny with a high in the upper 40s.

Flooding is still a problem in places like St. Marys, where officials are concerned about bacterial contamination from manure.

The Environmental Protection Agency and Emergency Management Agency are warning residents of Mercer and Auglaize counties about the issue.

The concern is that manure washed into lakes from fields during flooding and spread it throughout the counties. Clean-up kits will be handed out to residents of affected areas.

"That means potentially high levels of bacteria is now in the water that flooded that area," said WHIO-TV Reporter Kathryn Burcham. "The good news is that the EPA is not worried about toxins because it’s too cold for algae to bloom."