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Plug the holes, power the pumps ... As repair crews descended on the inundated city, the first step was to plug the breaches that let Lake Pontchartrain pour in. Less than two weeks after the storm, the major breaches had been filled, primarily with sandbags dropped from helicopters. Next, workers began getting power to the city's electric pumps
1 Rain and floodwater flow through underground culverts and canals to low points in the city, where pumping stations push them onward
2 Larger pumping stations then lift the water into open canals
3 At some points in the city, water flows to final pumping stations at the edge of Lake Pontchartrain, where pumps lift it over the levee
Vertical centrifugal pumps
Floodwall
Horizontal screw pumps
Outflow canal to Lake Pontchartrain
Underground drainage canal
HOW LONG WILL IT TAKE? Working at full capacity, the city's pumps could drain an Olympic-size swimming pool in 1.9 sec. At the current reduced pumping rate, New Orleans could be drained by Oct. 8, and surrounding areas by Oct. 18, the Army Corps of Engineers estimates
... and the water slowly recedes At the height of the flood, about 80% of New Orleans was under water. By Sept. 10 it was about 60% under water. More than 30 of the city's 148 pumps were running at reduced capacity, pushing 90,000 gal. per sec. out of the city
NEW ORLEANS
Approximate extent of highest flooding
Shallowest flooding
Deepest flooding
Interstate 10
17th St. Canal
Orleans Ave. Canal
London Ave. Canal
38 portable pumps are also in use around the city
Pump Station #6 (The city's largest)
Station #1, #2, #3, #7, #17, #19, #20, #16, #5, #4
City Park
Audubon Park
Levee
Levee
Lake Pontchartrain
Garden District
Mississippi River
French Quarter
Downtown
NORTH
Where levees breached
11.7 miles
DRYING OUT The highest point in New Orleans is the levee along the Mississippi River. The lowest parts are closest to Lake Pontchartrain. As more pumps come online, the water will recede toward the northern parts of the city
Pumping stations in New Orleans
Size indicates normal pumping capacity
Proportion in operation as of Sept. 10
Gallons of water per second: 1,500 3,750 15,000 37,500 67,500
Capacity unknown
TIME Graphic by Ed Gabel and Joe Lertola
Sources: Army Corps of Engineers; National Register Evaluation of New Orleans Drainage System