New Orleans- In accordance with the new operating procedure, the Corps responded to this weekend’s rain event by closing the London Avenue Outfall Canal Structure’s gates.
At 5:45 p.m. Saturday, September 12, 2009, a rare combination of easterly winds and heavy rainfall caused Lake Pontchartrain’s water level to reach the operational trigger of 2.5 feet and rising. The gates remained closed until the lake level subsided around 8 a.m. Monday.
Once the gates were closed, the Corps operated each of structure’s 8 direct drive and 12 hydraulic pumps to prevent water from approaching the canal’s 5 foot safe water elevation.
Each direct drive pump has the capacity to pump 340 cubic feet per second and was operated for up to five hours. The hydraulic pumps have a capacity of 200 cubic feet per second and each was operated between three and five hours. In an effort to reduce the noise impact to the residents, the Corps attempted to use the pumps along the University of New Orleans side of the canal whenever possible.
“Even though we had just implemented the new operating procedure this past Tuesday, I am happy to report that this weekend’s operation went very smoothly.” stated Chris Accardo, chief of the New Orleans District’s Operations Division. “From the performance of our pumps and the response of the team to our cooperation with the Sewerage and Water Board, everything went very well.”
Previous procedures called for closing the gates when the lake-side gage reached 4 feet and rising only during tropical events. Lowering that elevation during nontropical events reduces the risk of exceeding the canal’s safe water elevation. It further maximizes the Sewerage and Water Board’s pumping ability during heavy rainfall.
“Lowering the operational trigger to 2.5 feet and rising was the right thing to do,” added Accardo. “It increases our ability to work with the Sewerage and Water Board in reducing the risk of flooding to the surrounding neighborhood.”
Release no. 09-053