The cost to repair Clark County’s oldest bridge has ballooned by nearly $100,000.

Construction on the historic stone arch bridge will cost more than $623,800, up from the anticipated $524,000, according to Clark County Engineer John Burr.

The added cost to rehab the 141-year-old bridge is due to unforeseen issues with the aging bridge, Burr said. The bridge is now expected to be completed by early December, a few weeks later than expected.

Because of its deteriorating condition, county officials closed the bridge for a couple weeks in 2010 and then re-opened it to one-lane traffic.

“The bridge was severely deteriorated and would have had to be closed within a few years. This project will restore the bridge to full function two lanes without a load restriction and preserve the historic stone arch,” Burr said.

Fixing it is not cheap, but Burr said officials had few options.

“I either had to rehab the structure or leave it to one lane or load reduced as it’s been for several years,” Burr said. “With it being on the historic register I can’t tear it out or replace it. Those were the only two options.”

Eighty percent of the rehab will be funded by a federal transportation grant for historic structures and 20 percent will be paid for with state dollars, Burr said.

The bridge at the intersection of Rocky Point Road and Old Mill Road in Mad River Twp. carries 820 cars per day and was load reduced because of its condition as far back as 1966. It was reduced to one-lane traffic in 2004, according to county engineer records.

It was added to the Ohio Historic Preservation Office National Register in 2009 after a push from Mad River Twp. residents. It’s listed as the Old Enon Road Stone Arch Culvert. A historic marker is expected to installed on the bridge after construction is completed.

Mad River Twp. Trustee Kathy Estep said she is pleased that she and community members helped save the bridge.

“I’m absolutely thrilled we were able to keep a piece of history in our little township. I feel fortunate that it was brought to our attention in time to save it,” Estep said.

Estep said Samuel Taylor was paid $50 to build the bridge in 1871 for about $400 and that significance of the bridge makes saving it at a cost upwards of $623,800 worth it.

Charles Swaney, an attorney who lives near the bridge, was among the first local residents to ask area leaders to consider preserving the bridge.

Swaney said the bridge needed work, but questions why officials plan to restore the bridge to two lanes.

“There’s no question (preserving) it was the right thing to do. It would have been nice if it could have stayed a one-lane bridge because the cost of restoring it would have been a lot cheaper,” Swaney said.

Douglas Bailey, a historian in Yellow Springs, played a key role in getting in on the historic register.

Bailey describes the bridge as “picturesque” and a significant work of Taylor’s who also worked on the Heritage Center and built the county’s first sewers.

He said the second oldest remaining bridge in the county was built in 1917 and the third oldest was built in the 1930s.

“The very fact that this bridge still exists and has been maintained — though not very well — attests to the fundamental engineering and integrity of the work. It’s outlasted a lot of bridges,” Bailey said.

Still, Bailey said he’s not a fan of the “hybrid construction” of the bridge, which he said involves restoration and new construction that will allow for a two lane bridge.

“I suspect 100 years from now they’ll be replacing the new stuff they’re adding now and the stone will still be around,” Bailey said.

“We’re very fortunate it was preserved. It’s a compromise and it is a win-win. But in my personal opinion people were trying to create safe structures and that’s the priority. No question about it. But I think had it been a one lane stone arch bridge it would have been spectacular and the cost would have been far less.”