Grove City officials are reviewing potential options for addressing the flooding issues that occur in residents' houses during major rainstorms.
One option could involve setting up a program in which the city could pay for or provide grant money to cover the cost of installing preventative measures in residents' houses.
Cindi Fitzpatrick, the city's service director, reviewed the flooding issue and how the city might be able to address it at the May 4 City Council meeting.
The latest major flooding event occurred March 20, when 3.36 inches of rain fell over an 18-hour period, Fitzpatrick said. Grove City also received 1.2 inches of rain March 18.
"At that time, we were already 7 inches above average in total rainfall for the year," she said. "We had very saturated conditions."
Based on the basement-flooding reports the city had received from residents, the majority of issues occurred in areas of the city where the sanitary-sewer systems date back to 1965 or earlier, Fitzpatrick said.
The concentrated area of flooding also lies either within or in "the very adjacent areas" to the floodplain, she said.
After the March 20 event, the city reached out to the 66 homeowners who had reported water in their basements and made contact with 45 of them, Fitzpatrick said.
The city learned 82%, or about 37, of those homeowners did not have a backflow prevention device or standpipe installed for their plumbing systems, she said. Most of those who had those types of measures in place reported their systems were not functioning properly when the rain fell.
"Completely eliminating flooding in those areas is not realistic," she said. 'If you want to eliminate flooding in those areas, you would have to remove the structures."
Over the past decade, the city has made about $12 million in infrastructure improvements to addressing flooding issues, Fitzpatrick said.
One additional option to address the flooding issue -- building a retention basin to manage stormwater runoff to help prevent flooding -- might be too expansive and expensive to consider, Fitzpatrick said.
The anticipated cost of building a basin would be about $81,000 per acre-foot of storage, she said.
An acre-foot is the volume of water that would cover an acre to a depth of 1 foot, according to Merriam-Webster.
About 85 acre-feet of storage would be needed to detain a rain event like the city experienced on March 20, Fitzpatrick said.
Adding the cost of land acquisition, it would cost $10.7 million to 11.4 million to build a basin of that size, she said.
That is "extremely expensive," and it also would be difficult for the city to find a 25- to 40-acre site that would be suitable for the pond, Fitzpatrick said.
The city could opt to build smaller basins and accomplish the same purpose incrementally, she said. Although the cost would be spread out, the project ultimately would be more expensive to complete.
Another option would be to implement a program similar to the city of Columbus' Project Dry Basement, Fitzpatrick said.
In the program Columbus started in July 2004, residents who have experienced flooding in their basement could apply to have the city cover the cost of installing an approved backflow valve.
Based on information Columbus provided about its program, the estimated cost of installing a backflow device would be about $3,500, Fitzpatrick said.
If the city were to pay for a device to be installed at each of the 66 houses that had flooding in March, the cost would be about $230,000, "which is a lot more attainable" than the basin project, she said.
Council member Roby Schottke has presented council members and the administration with a proposal for a similar program that would involve Grove City offering a 50% matching grant of up to $5,000 to residents for the cost of repairs to their flood-prone properties.
Projects could include not only installing backflow valves but also cleanup and removal of water, dirt and debris; unclogging downspout and sump-pump lines to the street; or installing a new sump pump or a pump alarm that would indicate when a pump is not working, Schottke said.
"Backflow values are not the only parts that can be (an issue) in many of these floodings," he said.
His proposal is just a draft concept, Schottke said.
"There are many details to be worked out," he said.
The grant program could be funded using money that otherwise would be set aside for sidewalk-improvement projects, Schottke said. Addressing residents' flooding issues "is a more critical need" than repairing sidewalks, he said.