The Sandusky River in Tiffin was under a flood warning Wednesday night.
It was experiencing minor flooding at about 11:20 p.m., and moderate flooding was in the forecast, according to National Weather Service.
The river was at 9.94 feet at 10:45 p.m., and flood stage is 9 feet. The highest forecast is 10.5 feet at 2 p.m. today, according to the weather service.
It predicted the river level would decrease to 5 feet at 8 p.m. Monday.
"I'm sure there's a lot of surface water issues right now," said Dan Stahl, Seneca County's Emergency Management Agency director, at about 7:30 p.m. Wednesday.
Chief William Ennis of Tiffin Fire Rescue Division said water had started lapping on Front Street around 6:30 p.m., and he was sure there was going to be a lot of basement flooding occurring.
National Weather Service predicted a slight chance of showers before 1 a.m. today. Today is to be mostly sunny, with a high near 79, according to the weather service.