"If we get the heavier-than-expected rainfall, time will be of the essence," Edwards said. "This is a serious situation, but it's not something to be panicked about."
Before dawn Thursday, New Orleans Mayor Mitch Landrieu shocked city residents when he announced that a substation fire had knocked out a primary source of power for the city's network of drainage pumps. The outage is diminishing electricity for the pumps that serve the East Bank of the city, which includes much of central New Orleans, including downtown and the French Quarter.
With three other turbine stations also out of service for repairs or scheduled maintenance, New Orleans was left with just one primary source of electricity to power its pumps.
Generators and alternative power supplies from the city's main consumer electric supplier, Entergy New Orleans, will help offset some of the shortfall but probably couldn't power all the pumps during bouts of heavy rain, the mayor said.
"We are right now running on our last backup power source," Landrieu told New Orleans residents, many of whom also received emergency text messages warning them of the potential danger.
The fire and subsequent outage was another blow to a city that is still cleaning up after a major rainstorm Saturday flooded neighborhoods, some of which had several feet of standing water. Residents have been enraged about shifting accounts from city leaders about why it took so long for the water to drain.
The extended flooding was especially traumatic to residents because New Orleans is nearing the 12th anniversary of Hurricane Katrina. In 2005, the hurricane flooded 80 percent of the city and killed hundreds of people.
Shortly after the flooding last weekend, the leaders of the Sewerage & Water Board of New Orleans initially stated that all 121 of the city's pumps were operating during Saturday's storm. But on Tuesday, amid deepening community skepticism, officials admitted that eight pumps had been out of service when the rain began. On Thursday, board officials said 16 pumps were not working during the floods, according to news reports.
Under normal conditions, the New Orleans drainage and pumping system was designed to handle about an inch of rain an hour during the first hour of a storm, with the capability of handling half an inch of rain per hour after that. Saturday's storm dropped as much as nine inches of rain in just four hours.
At a hearing Tuesday, New Orleans council members vowed to investigate how the city could appear to be so unprepared for flooding just as the region heads into the peak of hurricane season.
On Wednesday, the National Oceanic and Atmospheric Administration increased its forecast of tropical weather systems this year. It now expects 14 to 19 named storms, including two to five major hurricanes.