Progress in construction at BC tunnel and Oakville flood gate continuesFeb 26th, 2013 | By Jessica Gonzalez | Category: top story
Highway 23 travelers in and out of Plaquemines Parish have endured their share of traffic woes over the past several years with promises of improvement seemingly a
Installation of floodgates across LA Hwy 23 at Oakville has caused traffic slowdowns for over a year now and floodgates installed at either side of the always wet Belle Chasse Tunnel caused ground water to pour into the tunnel. Both projects are part of the Western Closure in the New Orleans Hurricane Storm Damage Risk Reduction
System providing flood protection for the Westbank of Orleans, Jefferson and upper Plaquemines Parishes.
Problems arising as a result of flood protection improvements being performed by the U.S. Army Corps of Engineers are being addressed, according to Col. Ed Fleming,
Commander, U.S. Army Corps of Engineers, New Orleans District. The support columns on the Oakville gates are being repaired and wells are being installed to allow
groundwater to be pumped from around the tunnel.
Construction of floodgates on either side of the Belle Chasse Tunnel has been on-going for a year now. Part of the process required the driving of sheet pilings around the perimeter of the project. An un-wanted result has been the accumulation of groundwater seeping through the approach walls on either side of the tunnel. Four underground wells installed on either side of the tunnel have reduced the problem but not eliminated it. Four additional wells are being installed to hopefully solve the problem.
“Ground water was always present. What you see above ground is about 30 percent of the project. Below are sheet pilings and a steel wall about 30 feet into the ground,” said Col. Fleming. “Water used to be able to move out of the area but the sheet piles restricted the seepage. What we did was install four relief wells on the unprotected (canal side) of the walls and that has worked.”
Col. Fleming said after the first pumps were installed, ground water continued to accumulate on the protected side as well. Four additional relief wells are being installed and that should remedy the problem. None of the work around the tunnel had any impact on the structural integrity of the tunnel and did not affect the leaks inside the tunnel in a positive or negative way, according to the Corps.
State Senator David R. Heitmeier, O.D. said his office has received many complaints about the tunnel and the Belle Chasse bridge.
“While the hurricane protection gates added on each side of the tunnel have caused some new issues, we all know that replacing the tunnel and bridge is the permanent
fix,” Heitmeier said. “The state is continuing to do patch work on the tunnel and we are getting a major overhaul on the lift mechanisms on the bridge, but reality is these are 50 year-old structures and there is only so much we can do,” he added. Heitmeier said he is continuing his quest to find funding needed to replace the structures with a new bridge estimated to cost from $170 million to $200 million.
Oakville Flood Gates
As for the flood gates at Oakville, the weight of the gates caused the support columns to develop cracks which were unacceptable according to Julie Vignes, Branch Chief, West Bank & Vicinity, U.S. Army Corps of Engineers, New Orleans District. “We’re through the demo of the columns and are ready to rebuild them to support the weight of the floodgates,” she said.
Both projects should be complete in the April to May time frame, according to Vignes. This hurricane season, should a problem arise, the gates will be able to be closed and the area protected.
“We will no longer need sheet piles, Hesco baskets or sandbags to close the area.” Col.
Fleming said. Upon completion, the projects are turned over to the appropriate authorities to operate said Fleming, which means depending on the project usually
means, the state or appropriate levee district.