GREENFIELD — A decades-old flooding problem in downtown Greenfield is coming closer to being resolved, but it will be at a high price.
An engineering study that focused on ways to reroute Potts Ditch shows cost estimates ranging from $9.3 million to $22.6 million.
City engineer Mike Fruth says he recommends an option estimated at just shy of $10 million, though final costs won’t be determined until the process proceeds further.
Potts Ditch is an underground tunnel that was built roughly 100 years ago in several stages. It starts at Fourth Street and heads southeast under buildings and homes to south Spring Street.
The underground tunnel also has a few openings.
“It begins to flood at the openings because the openings are not large enough,” Fruth said. “But over an extended period of time in a rain event, (water will) go to other areas.”
The most recent flooding happened in 2008, when storm water rushed over the banks of the ditch and flooded into homes and basements. The city spent roughly $60,000 to rehabilitate part of the ditch, but officials have known for years that those kinds of patches are just short-term solutions.
“That’s (a problem) that’s been there for years,” said Mayor Dick Pasco, who says city officials were talking about fixing Potts Ditch when he was on the city council 10 years ago.
The engineering study was sent out to city council and board of works members this week, and Fruth will give presentations to both groups at their meetings next week.
Fruth said he knows it will take time to discuss how to pay for such a costly project. If the work is approved, it will take multiple years to complete.
“As they begin to look at budgets for 2013, if there’s money on hand to do the next step, we should do that,” he said. “But if we need to wait till next year, we’ll wait till next year. The problem is not going to go away.”
While it hasn’t flooded in recent years – especially not this year due to the drought – Fruth said city officials should consider what the study suggests as a way to fix the project.
The new route for the ditch would be underneath several streets and require extensive roadwork. A new box tunnel about 14 feet wide and 6 feet high would be installed to reroute water, and the current ditch would be abandoned.
The preferred route goes along Grant Street, East Street, North Street and Spring Street. Fruth said it is the preferred route because it provides the least disruption to Greenfield’s busiest roads – Ind. 9 and U.S. 40 – and is also closest to the current ditch.
The study, by the engineering firm Clark-Dietz, cost $66,200. A more in-depth study would be required for the project to get under way. There would also have to be money spent on relocating utility lines and removing roads.
Other routes that are less expensive as shown in the study do not provide a complete solution, Fruth said. One, for example, keeps an old tunnel that should be rebuilt. Another involves several blocks along Ind. 9 and U.S. 40, which would disrupt traffic and may not be approved by the Indiana Department of Transportation.
The preferred route would tear up the road in front of Pasco’s home. While Pasco jokes that he’s concerned about that, he understands the problem needs to be addressed.
He said the city may have to borrow money for the project, but he also hopes there are grants available to help pay for it.
“I’m not aware of any grant available for that type of work, but certainly we’ll look into it,” Fruth said.