This article covers the levee system and infrastructure repairs in New Orleans, Louisiana following Hurricane Katrina. Though Hurricane Katrina did not deal the city of New Orleans a direct hit on August 29, 2005, the associated storm surge precipitated catastrophic failures of the levees and flood walls. The Mississippi River Gulf Outlet ("MR-GO") breached its levees in approximately 15 places. The major levee breaches in the city include the 17th Street Canal levee, the London Avenue Canal, and the wide, navigable Industrial Canal, which left approximately 80% of the city flooded. While ownership, definition of requirements, operation and maintenance of the system belonged to the Orleans Levee Board, federal responsibility for New Orleans' flood protection design and construction belongs by federal mandate to the US Army Corps of Engineers. Flooding from the breaches put the majority of the city under water for days, in many places for weeks. The Corps made emergency repairs to breaches, as pumps worked at draining the city. Hurricane Rita brushed the city nearly a month later, causing reflooding of some areas, most significantly from water flowing through incompletely repaired levee breaches. Background Flooding due to rain and storms has long been an issue since the New Orleans' early settlement due to the city's location on a delta marsh, much of which sits below sea level. The city is surrounded by the Mississippi River to the south, Lake Pontchartrain to the north, and Lake Borgne to the east. Construction of the levees along the River began soon after the city was founded, and more extensive river levees were built as the city grew. The levees were originally designed to prevent damage caused by seasonal flooding. Today, the floodwalls atop the 17th Street and London Avenue Canals are used for drainage, to pump water from the city streets out to Lake Pontchartrain. These floodwalls are one foot (300 mm) wide at the top and widened to two feet (600 mm) at the base. The visible portion is a concrete cap on steel sheet pile that anchors to the wall. Sheet piles are interlocked steel columns, in this case at least 30 feet (10 m) long, with 6 to 10 feet (2 to 3 m) visible above ground; examinations afterward showed that some pilings were not as deep as specified. The wide, navigable Industrial Canal is used for shipping. The heavy flooding caused by Hurricane Betsy in 1965