To avoid flooding in New Orleans after a rain storm, the city's Sewerage and Water Board pumps rainwater from the city into three drainage canals which then flow unrestricted into Lake Pontchartrain. While critical to prevent flooding from rainfall, these canals are vulnerable to storm surge from Lake Pontchartrain during a hurricane, and consequently are lined with floodwalls along both sides to protect storm surge from overtopping the canals and flooding the city. However, during Hurricane Katrina, several breaches occurred in the canal floodwalls allowing significant amounts of water to enter New Orleans from Lake Pontchartrain. In its efforts to restore pre-Katrina levels of hurricane protection to New Orleans by the June 1st start of the 2006 hurricane season, in late 2005, the U.S. Army Corps of Engineers (Corps) considered strengthening the drainage canal floodwalls but decided to postpone this effort due to cost and time constraints. Instead, the Corps decided to install three interim closure structures (gates) at the points where the canals meet the lake. These gates would be closed during major storm events to prevent storm surge from entering the canals and potentially breaching the canal floodwalls and flooding the city. Due to space constraints along the canals and the limited amount of time it had before the start of the 2006 hurricane season, the Corps decided to procure 34 large-capacity hydraulic pumping systems1 to provide the most pumping capacity possible by June 1, 2006. The Corps acknowledged that its decision to install the gates and provide pumping capacity that was less than what was needed to keep the city dry could result in some flooding by rainfall but believed that the risk from a hurricane-induced storm surge was far greater than the risk of flooding from heavy rainfall. During the process of acquiring, testing, and installing the pumping systems for the drainage canals, many concerns were raised by the media about potential problems with the operation of these pumping systems, and GAO was asked to examine the (1) specifications and requirements of the contract and the basis for selecting the supplier of the pumping systems; (2) concerns identified during factory testing and the Corps' rationale to install the pumping systems in light of the factory test failures; (3) actions the Corps has taken to address the known problems with the pumping systems; and (4) pumping capacity that existed on June 1, 2006, the capacity that currently exists, and the capacity that is planned for the 2007 hurricane season.
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