DES MOINES, Iowa (AP) — Officials in eastern Iowa on Wednesday ordered residents to evacuate some rural homes along the Iowa River because of the threat that rising water from a nearby reservoir could spill over a dam's spillway and flood the area.
The Johnson County Emergency Management Agency issued the evacuation order for several unincorporated neighborhoods in low-lying areas due to concern about the Coralville Lake Reservoir, located several miles north of Iowa City. Recent heavy rains have caused the reservoir level to climb and projections show it will rise to within a foot of the spillway.
If it tops the spillway, water would pour uncontrolled into the Iowa River. However, scheduled increases of water flow from the reservoir will also mean low-lying areas will be subject to flooding.
"This is getting pretty serious around here," said Johnson County Supervisor Terrence Neuzil.
The reservoir was about 10 feet below the spillway on Wednesday and rising.
An earlier projection showing that the reservoir level would exceed the spillway prompted the evacuation order, as officials planned to increase the flow of water entering the Iowa River in the next few days. Electricity and natural gas will be turned off in the affected areas.
The reservoir level is rising due to repeated thunderstorms that have dumped up to 5 inches of rain in parts of eastern Iowa. Water has topped the spillway only twice, in 1993 and 2008, and it led to significant flooding in the area.
Last year, county officials also warned the reservoir might spill over and issued an evacuation for many of the same neighborhoods. It eventually crested a few feet below the spillway.
The potential for flooding meant Iowa City officials went door-to-door Wednesday to speak with people in low-lying areas to warn them about the swollen river. Officials planned to issue recommended evacuations Wednesday for homes and businesses on the north and west side of the city. There are no mandatory evacuations in place.
City spokeswoman Shannon McMahon said the city is prepared to deal with the rising waters because of its history with flooding.
"Unfortunately, when we have weather patterns that stall out and impact our river system like this, there's not much we can do to prevent it," she said. "We just have to use the tools that we have ... to protect the flood prone areas and to encourage people to keep an eye on the river levels."
Apart from possible flooding of rural areas, officials also warned that if water flows over the spillway, flooding is possible in Iowa City, including the University of Iowa campus. The UI campus was devastated by flooding in 2008.
"Obviously the landscape has changed a bit since 2008," Neuzil said. "Several cities have invested in significant flood protection. Many houses have been removed since 2008. So it's hard to predict what kind of impact that will have if it does go over."
The University of Iowa placed protective measures around campus Wednesday in response, including adding an interlocking metal wall around the Art Building West, which holds a library and classrooms.
"I think it's very precautionary," said university spokesman Stephen Pradarelli. "We went through this last year, and we'd rather err on the side of taking measures and not have something bad happen."
Officials are also monitoring high water levels at other rivers. At the Cedar River near Conesville, water was at 17.69 feet as of Wednesday afternoon, several feet above flood stage. It is expected to crest later Wednesday. The Mississippi River at Muscatine was at 21.11 feet, several feet above flood stage. It is expected to crest Friday at 22.6 feet. At Burlington, waters were at 20.54 feet, several feet above the flood stage. It was expected to crest Saturday at 23.9 feet.
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