After a heavy snowstorm and large rain event in early February, City of Milford staff responded to a sinkhole along the Riverwalk near the Washington Street bridge. Initially, according to Brad Dennehy, Parks & Recreation Director, it was thought the sinkhole was due to settlement of large areas of concrete sidewalk due to possible stormwater drain erosion.
“Once the tide went out, we had an incredibly low tide that day, we found that not to be the case,” Dennehy said. “We believe that, over the years, the Mispillion River has come in and large cracks, both vertical and horizontal, the river has undermined the entire section of concrete.”
Dennehy explained that it was not just a question of removing the sidewalk and pouring new, but there is concern that the entire concrete wall under the handrail could collapse, something he said was not in his wheelhouse to fix. He reached out to GPI, the engineering firm that completed the repairs to the Walnut Street bridge who provided a proposal for $35,000 to conduct a study of the issue.
“Ordinarily, you would go back with sheet piling and drive it with a crane or a ram, and then you would pour concrete on top of it. But I’d like to sort of see what other options we could do, perhaps build some sort of ledged-type terrace to make it look more esthetically pleasing, where perhaps kids could go down there and fish off it,” Dennehy said. “Or have some larger boulders, we call it rip rap, but they’re kind of like the big boulders that you see along the Riverwalk, rather than having that big, vast area of concrete.”
What Dennehy was requesting from council was authorization for a professional structural engineer to come look the area and provide three different options. He explained that if council visited the area, they would see a large six-foot chain link fence to keep traffic out of it.
“This is not going to be cheap, and it is not going to be a quick fix,” Dennehy said. “This did not happen overnight, and it has likely been going on for some time. But it is critical that we move forward on this.” Dennehy also commended Finance Director Lou Vitola for his ability to “find and move money” when these issues came up. Costs would be covered by existing Capital Improvement Project (CIP) funds.
Mayor Todd Culotta confirmed that the $35,000 was just for the survey and then asked if this was the only firm Dennehy contacted.
“Correct I’ve been through, I think, three different engineers with the old firehouse building to find a structural engineer in the state of Delaware. It’s very difficult. It’s easy to find a civil engineer, but structural engineers are a dying breed. So, these guys, one, they are local. They’re an employer in Milford,” Dennehy said. “So, to be honest, I’ve not tried to seek any other engineers, because, having been down this road before, Mayor, I can’t find a structural engineer in the state of Delaware.”
Because the project was along the water, Dennehy explained the Army Corps of Engineers would be involved and the engineer’s needed expertise on the pressure of the water as well as hydrology which is very different than building roadways. Culotta questioned why council needed to approve the funding since staff was authorized to approve anything under $50,000.
“In part of the memo, I explained I need authorization because we’re taking funds from other approved CIP projects,” Dennehy said. “I think it is important in the year of transparency for council to know that we are taking money from already approved projects for this.”
Vitola agreed.
“Although it is flattering that Brad noted I can find the funding and move it around, I really can’t,” Vitola said. “I can make a suggestion, but that’s why it’s on the agenda for approval because even though it is the same department and a similar project, it’s not approved in the CIP.”
Council approved the request unanimously.
