When the Ohio River floods, water backs up into other rivers and streams including the Little Miami, Licking, and the Mill Creek. Cincinnati has infrastructure in place to prevent damage along one of the area's most developed waterways.
A barrier dam keeps the Ohio River from invading the Mill Creek Valley. Cincinnati Stormwater Management Engineer Eric Saylor says the city activates it when the Ohio hits or is expected to hit 52 feet.
"We pump the Mill Creek, force it into the Ohio River to protect the Mill Creek Valley. Not only this valley but all the way up the Mill Creek. We even coordinate all the way up to Winton Lake."
That reservoir releases into the Mill Creek when it gets full.
Saylor says the coordination helps crews know how many pumps to run. There are eight altogether. Each can move a billion gallons of water a day.
"This was being built at the same time, roughly speaking, as Hoover Dam. But Hoover Dam wasn't ready. So they brought the pumps that were going to go to Hoover Dam to us here at barrier dam."
Supervisor Rahn Wuest says bulkheads are bolted together to form the dam. An electric crane drops as many into place as needed. He says Stormwater Management has to inform Duke Energy when they go online so the utility can accommodate the energy needs of the crane.
"Each one's about five feet tall. They weigh eleven tons apiece. We'd be above the 1937 flood level if we had them all in there," Wuest says.
The '37 flood crested at 80 feet. Wuest says Thursday morning's bulkhead configuration could hold back water reaching 65 feet.
The Army Corps of Engineers built the dam after that 1937 flood and turned it over to the city. Saylor says the Corps inspects the dam every year.
"If we do not keep it up to their standards, they fail us on the inspection, which has never happened. They've always given us a passing rating. But if we were to fail, we endanger the city getting FEMA (Federal Emergency Management Agency) certification if there were a large flood," he says.
That failure could also mean higher flood insurance rates.
Saylor says the barrier may pass inspections, but it's getting old. One of the cranes needs to be rehabilitated, there's been extensive ongoing work on the pumps, and the entire facility needs electrical and safety upgrades.
It's paid for from the stormwater fund, which comes from a fee charged to every developed property in Cincinnati.
Is there enough money in the fund for all the necessary work? Saylor laughs, saying, "We're putting forth a plan for the next few years. There'll be proposed rate increases associated with that."
An increase would have to be approved by Cincinnati Council.
He says the barrier protects not only roads and businesses in the Mill Creek Valley, but also an important Metropolitan Sewer District facility.
"That plant is the largest wastewater treatment plant in the entire Tri-state. And if that couldn't take sewage, it would be a true environmental disaster," Saylor says.
More rain is expected this weekend. The National Weather Service forecasts the Ohio River to crest near 60 feet on Tuesday. It hasn't been that high since 1997.