Coralville Lake no longer predicted to go over emergency spillway, but flood threat remains

IOWA CITY – Coralville Lake is no longer predicted to go over its emergency spillway, but don't take that to mean the threat of major flooding has passed.

Underscoring that was Iowa City's request Sunday for a small number of voluntary evacuations, the pending closure of the road over the dam at Coralville Lake and the possibility of more road closures throughout the county.

'It's important for folks to understand that this is going to be a prolonged event,' Terrence Neuzil, a Johnson County supervisor serving as spokesman for the county's Emergency Management Agency, said Sunday. 'The (Iowa) River is going to be flooded for a while.'

The Army Corps of Engineers, which oversees the lake, is now forecasting the lake will crest at 711.5 feet above sea level on June 7. That's down from the 712.8 foot prediction made Saturday, and it is below the spillway, which is at 712 feet.

Receiving just a few hundredths of an inch of precipitation in the Iowa River basin on Saturday and dry forecasts for Sunday and Monday helped bring the lake forecast down, Neuzil said.

But the lake is still high – just over 707 feet Sunday compared with the normal summer elevation of 683 feet – and it will be high for some time, officials said. They are expecting the flood threat to remain much of the summer, and another wet stretch like what was seen last week could send predictions soaring again.

The National Water Service is forecasting the Iowa River in Iowa City to crest at 25 feet, which is right at 'major' flood stage, on June 4.

'We're not out of the woods yet,' said Dee Goldman, the lake operations manager. 'There's still a very real risk there. But every little bit we can get out of the reservoir' helps.

The amount of water going through the dam's gates, which are wide open, was 18,100 cubic feet per second Sunday morning. That's expected to hit 19,500 cfs as the lake crests. That's also an improvement from Saturday.

The corps moved to 24-hour operations at the lake Sunday to monitor the situation, including inspecting the dam and reading gauges, Goldman said. Everything is working as it should be at this time, he said.

Flooding remains a concern.

Iowa City police officers on Sunday delivered voluntary evacuation notices to three homes on the 800 block of Normandy Drive, which has been closed by floodwaters, and nine homes on Taft Speedway.

'Just a recommendation to them, a heads up, that we have concerns that emergency personnel would not be able to make it in later," city spokeswoman Shannon McMahon said.

Taft Speedway resident Joel Wilcox, his wife and two kids moved Friday to his mother's home, across the street in the Idyllwild neighborhood

They raised their house 8 feet after the 1993 flood and currently have about 16 inches on the lowest level, which is not lived in, he said. Water is knee deep outside the home, making it difficult to enter and exit.

'It is daunting and incredible that a week ago I wasn't even thinking that there was going to be a flood,' said Wilcox, 60. 'The realization of it came up awfully suddenly.'

In addition to the flood damage and mandatory home evacuations that already have occurred, the county is keeping an eye on Winter Eagle Road just south of Terry Trueblood Recreation Area in southern Iowa City and Ely and Swan Lake roads near the lake.

In  Hills south of Iowa City, about 2,000 feet of berms have been installed and the the small town should be OK at the predicted flow of 19,500 cfs, Neuzil said.

Three groups from two special law enforcement water teams – one based out of Cedar Rapids; the other in Johnson County – were on the Iowa River Sunday shooting video and still photographs of water damage.

About 30 Johnson County buildings, mostly homes, are currently damaged or under water with an estimated $2 million in damage, Neuzil said.

The worst-case scenario, based on a lake outflow of 21,000 cfs, would threaten 64 buildings and has the potential to cause $23 million in damage, he said. About 20 miles of roads would be affected by floodwaters in that situation and about 15,000 tons of debris would be in the Iowa River, he said.