In 2012 the U.S. Army Corps of Engineers awarded the PCCP Constructors the contract to build three permanent canal closure and pump station structures to block hurricane storm surges at the Lake Pontchartrain mouths of the 17thStreet, Orleans Avenue and London Avenue drainage canals in New Orleans.
Temporary pumps and floodgates near the mouths of the three canals will stay in place until the permanent structures are completed. The joint venture, which includes Kiewit Louisiana Co., Traylor Bros. Inc., and the M.R. Pittman Group LLC, will be paid $614.8 million to build the three structures, which are the final major post-Katrina improvements to the New Orleans area levee system. Under the contract, the new stations must be designed to block storm surges from Lake Pontchartrain caused by a hurricane with a 1-percent chance of occurring in any year, commonly referred to as a 100-year storm. The structures also must take into account expected increases in the height of the lake’s water level during the next 50 years, to account for sea level rise caused by global warming and local subsidence.
In addition, the stations must be able to pump rainwater from each canal into the lake at a rate that will keep the water levels in the canals low enough to avoid overtopping or damage to the floodwalls. The pumping requirement assumes that the Sewerage and Water Board’s pumping stations would be operating at their full capacity.
The contract requires that when the surge closures are operated during storms, the pumps move 12,500 cubic feet per second of water from the 17th Street Canal into Lake Pontchartrain; 2,700 cubic feet per second from the Orleans Avenue Canal, and 9,000 cubic feet per second from the London Avenue Canal.
Finally, the stations must be designed to allow the pumps to be repositioned in the event that local officials decide to dismantle the interior pumping stations and deepen the canals to carry rainwater to the lake. If that occurs, the water intakes inside the canal will have to be lowered.