Daniel Monks, the town's development director and zoning administrator, said the "flood wall" near the intersection of County and North Branch streets was compromised by the raging water caused by the storm's heavy rains.
"That flood wall, during the Irene event had two big sink holes," he said.
The power of the river apparently eroded land beneath the wall, causing the sink holes to develop. Town highway crews worked quickly during the storm to fill them to ensure the integrity of the wall. Subsequent inspections by the town's engineer, Roy Schiff, have led town officials to seek a permanent repair to shore up the wall, Monks said.
"He looked at it with some structural engineers from his firm, and without digging huge holes or doing too much exploration, they felt pretty confident that there was some undermining of the structure, just given the way that the sink holes formed. They developed a recommended plan for repair where you would drill holes into the base of the retaining wall and pump concrete into it. Basically, it would fill the void underneath it," Monks said.
The repair project is estimated at about $30,000, according to Monks. It does not need to be completed immediately, though, he said.
"They also said, 'Hey, that's not going to fall over tomorrow. If you have another big event you could have a problem, but you don't have to do this tomorrow,'" Monks said. "All the engineers have said it's not going to just fall over."
The town has been moving forward with planning a repair next spring. In the meantime, they have sought assistance from the U.S. Army Corps of Engineers, which constructed the wall. Monk said the corps is likely to repair and pay for the fix. Engineers with the corps are planning a site visit next week, he said.
"We have written indication that they plan to and hope to," he said. "It may not be the exact thing, but it would be similar (to the town's plan.)" Monks said the town has been informed that a repair project Monk said the corps is likely to repair and pay for the fix. Engineers with the corps are planning a site visit next week, he said.
could be completed before winter. "I do have hope and relative confidence that they're going to perform the repair," he said.
A failure of the wall during another major storm could be "catastrophic," Monks said. But the identified repair "should protect folks in that area from a failure," he said.
"If it failed during an Irenetype event, the erosive power there would wash down County Street," Monks said. "That's why the wall is there, because historically, the river has gone that direction."
The town will be able to fund the project if needed, Monks said.
"I would bet that the Select Board would authorize us to do the work. We might have to postpone a highway project. We might have to borrow though the Irene line of credit," he said.
The Federal Emergency Management Agency could also foot the bill, but FEMA has not yet made a determination on funding more pressing repairs that have already been completed by the town.
"There's also still out there pending the whole issue of FEMA eligibility. It's conceivable that if the corps said, 'We're not going to do it, we don't have any money, you're on your own,' we could eventually convince FEMA to pay for it. But, we've already been put on notice that FEMA has not made a decision regarding eligibility on a lot of stuff, so we couldn't certainly count on that money," Monks said.