The National Weather Service put the official rainfall in New Orleans at more than 7 inches over the span of six hours Wednesday morning, with some personal weather stations dotting the city registering much higher levels. In the Central Business District, a rain gauge tallied up 11 inches by mid-morning. In some areas, the rain fell at more than 6 inches an hour, which is several times the rate than can be pushed by the city’s pumps into Lake Pontchartrain.