The flood potential in eastern Iowa along the Iowa River has diminished enough that the Iowa Corps of Engineers has downgraded its response from “high alert” to monitoring mode. A spokesman for Johnson County Emergency Management, Terrence Neuzil, says the means they can keep watching, but downstream flooding has become less likely. “The situation is obviously at a point now where we’re pretty comfortable with the latest projections from the U.S. Army Corps of Engineers that levels of the lake at this point look good for not going over the spillway,” Neuzil says.
Projections last week at one point showed the water possibly going over the spillway around Wednesday or Thursday of this week. That water went over the spillway in 1993 and 2008 and caused severe flooding downstream.
Neuzil says they now will watch for a significant change in the weather that would dump more rain into the watershed. “And, when we say significant rain event, we’re watching Marshalltown, we’re watching Tama, we’re watching Belle Plaine, Marengo, all the way down all the way into the Corps area,” Neuzil says. “And so, all that water from the Iowa River from those communities does come in to the Corps, the Corps of course holds that water back and then releases it at a slower pace.”
The University of Iowa downstream in Iowa City started preparing for possible flooding at the end of last week. Spokesman Stephen Praderelli says they are cautiously optimistic about the change. “With the rainfall predictions and the Coraville Reservoir going down and the flow of water through he Iowa River, we are hopeful that we have avoided flooding this year,” Pradarelli says.
He says the U-I decided to take action last week when the projections from the Corps and river gauge readings all indicated possible flooding. “We put flood barriers up around low-level buildings and along the east and west banks of the Iowa River as a precautions. So, we were well protect and we’re glad we took those measures and we’re happy if they ultimately are not needed,”Pradarelli says.
The school used what are called HESCO barriers that are put in place and filled with sand to block floodwaters. Pradarelli says they will leave the barriers up until the water level is low enough to not cause a concern. “We know in Iowa the weather can be unpredictable and..rather than start dismantling them early, we want to keep them there until we are absolutely confident that we can dismantle them,” Pradarelli says.
The university suffered significant damage from the 2008 flooding and construction projects in that recovery are still underway and some of the areas that had to be protected with the new flood potential. Neuzil from Johnson County says the Coralville Reservoir Lake is expected to peak Tuesday at 708 feet. That’s four feet short of the 712-foot emergency spillway.
He says the Corps is currently moving the water out of the Reservoir Lake downstream at 18,000 cubic feet per second. That will keep water levels high on the Iowa River. Likely staying at flood stage until July 14th.