CORALVILLE, Iowa — Forecasts for the Coralville Lake and, consequently, Iowa River flooding are improving in Johnson County.
For the second day in a row, on Friday, the Army Corps of Engineers downgraded the expected crest for the Coralville Lake to 710 feet by July 10, two feet below the emergency spillway.
That is good news for communities downstream that scrambled to erect flood walls earlier this week. Already several homes are under mandatory evacuation as the river level has spilled out of its banks in some areas. Several roads, including a stretch of the busy Dubuque Street, less than a mile from Interstate 80, remains closed.
Just Wednesday water was predicted to top the spillway, a sign of how rapidly the situation has been and can continue to change.
The spillway, which was built to help control flooding, has only been breeched twice, in 1993 and 2008. It came with disastrous consequences for communities downstream.
There is some more promising news for people living downstream from the reservoir. The Corps now expects to lower outflow from the reservoir from 18,000 cubic feet per second to 15,000 cubic feet per second next Sunday, July 13. That means flooding levels will stay at current levels through next week.
Still, the area remains at the mercy of the weather, officials said.
“This river water is going to be around for a while. These flood walls are going to be around for a while,” Terrence Neuzil, spokesman for the Johnson County Emegency Management Agency, said on Friday. “It's a wait and see with the weather over the next five to seven days. We are not out of the woods yet.”
Storms in Marshalltown, Marengo or here in Johnson County in the next week could quickly change the outlook, Neuzil said.
The latest models account for a prediction of 1.2 inches more of rain water in the Iowa River basin over the next five days, Neuzil said.
Neuzil said climbing on flood walls is prohibited, and that boaters are reminded to wear life jackets and be cautious of debris.
An emergency shelter set up by the American Red Cross at the Johnson County Fairgrounds went to standby mode as of noon Friday.
Johnson County is now asking people to report any storm damage to the county by clicking here.