In 2011, the City repaired three pipes comprising the outfall conveyance for Coleman Lake under Main Street to Joe’ s Bayou, requiring an emergency excavation and repair of the piping, fill, base and pavement of Main Street.
At that time it was noted that the standpipe structures in the lake would likely need replacement in the near future.
It was recently brought to staff’ s attention that the lake level was dropping, and that there was likely a leak in one of the standpipes. Upon investigation, staff determined that the northernmost standpipe had rusted through and partially failed below the waterline. It now appears that failure is accelerating, according to city documents.
Looking at the project, Ustick said it would cost the city a price not to exceed $75,000 for construction. The funds would come from FEMA, via reimbursement from Hurricane Ivan.
As for the project, Schmidt said “we’ve been scrambling” to put a design together for this project.
“What we have now is what we think is the best long-term solution,” he said. This would consist of two sheet pile structures that are filled with concrete.
The sheet pile will be driven down 14 feet.
Schmidt said the best way to install the sheet pile is to vibrate them into the sandy bottom of the lake.
“We have every expectation this is going to solve this problem…” Schmidt said.
Schmidt said the project should be able to be completed in a few weeks after work begins.
Once the outer sheet pile wall is installed, Schmidt said they would be able to control the water flow of the lake.
“We do still have to permit this with the Army Corps of Engineers and the Department of Environmental Protection,” Schmidt said. “We feel as we can get this permitted pretty quickly.”
He said he feels confident that the work could begin in about a month.
Coleman Lake is owned by the Kelly Trust, but the city has an easement over the drainage structure, Ustick said.
Capt. Mike Parker is at the mic.
He is telling city leaders that “the scoping” might not have seen everything the city needed to see and that there are some breaks at the bottom of the pipe.
“What I saw and Jim saw, were some breaks at the bottom,” he said. Parker said this is a matter of urgency.
“It’s dropping over an inch a day,” he said. “It will turn into a mud pit in a hurry if we don’t get it plugged.”
“We need to stop that leak as soon as possible,” he added.
Schmidt said a permit from the Corps of Engineers could take anywhere from a week to more than a month. He said the cost to scope the pipes would be roughly about $1 a linear foot. That would not need to be permitted.
“Is there a temporary plug…?” Bagby asked. “I’m just trying to figure out if there’s a recommended patch.”
Schmidt said they are old and rusted pipes, and they can break very easily. He said trying to patch the holes could also make the problem worse.
“We’re afraid quite frankly to get to close to it and try to do anything with it, because we might cause more damage,” he said.
The motion to approve the funding and proceed with the project is up for vote and approved unanimously.