NORCO, La. (AP) - The Army Corps of Engineers opened a major spillway upriver from New Orleans on Friday - four days earlier than planned - because the Mississippi River rose faster than expected, fed by downpours in Louisiana.
Working between thunderstorms, crews used cranes to haul up huge timbers, opening three of the Bonnet Carré (BAH-nee KEHR-ee) Spillway’s 350 bays by midafternoon Friday.
The spillway protects levees in New Orleans, 28 miles (45 kilometers) downriver. The day’s goal was to open 40 to 50 bays in the 1.5-mile-long (2.4-kilometer-long) concrete structure, Corps spokesman Ricky Boyett said.
He said the Mississippi River had risen 6 inches (15.2 centimeters) in 24 hours, with more rain expected through the weekend.
That took “a tremendous amount of rainfall” between Baton Rouge and New Orleans, said National Weather Service hydrologist Jeff Graschel (GRUSH-uhl).
Baton Rouge-area stations reported 3.7 to 6.4 inches (8.6 to 16.25 centimeters) of rain in the 24 hours ending at 7 a.m. Friday, the National Weather Service said. Local governments across much of the state made sandbags available Friday.
In Zachary, outside Baton Rouge, firefighters evacuated six people from a flooded neighborhood Friday, news outlets reported.
In northwest Louisiana, officials called for a voluntary evacuation of about 35 houses in part of Bossier Parish, saying flooding could make it difficult to get there. Fifteen homes in Haughton, near Shreveport, flooded Thursday. In nearby Princeton, neighbors in a pontoon boat met a family at the front door of their flooded home to get them to a sheriff’s office high-water vehicle, the Bossier Parish Sheriff’s Office said in a news release.
A stalled frontal system is bringing daily waves of showers and thunderstorms through the weekend, said Michael Hill, a National Weather Service meteorologist. “We just have to watch every 12 to 24 hours for another round of storms, possibly with heavy rainfall … until this frontal boundary pushes off,” he said.
From the spillway, water is diverted along a 6-mile (9.7-kilometer) course of guide levees to Lake Pontchartrain, after which it flows to the Mississippi Sound in the Gulf of Mexico.
Never before has the spillway been opened twice in one year.
The second opening comes a little less than a month after it was closed April 11. It had been opened unusually early, in February.
“The biggest challenge we have is we’re unable to operate the cranes in high wind or in lightning,” Boyett said Friday. “It’s hard to say how long it’s going to take, based on the weather conditions. But they will be opened today.”
New Orleans’ levees were built to handle up to 1.25 million cubic feet of water per second flowing past - enough to fill the Empire State Building in 30 seconds. Federal law requires opening the spillway when that mark is reached, Boyett said at a news conference Thursday, when the corps had said it planned to open the spillway Tuesday.
“The risks in not operating the spillway as it is designed … would be potentially catastrophic,” he said.
Graschel said rivers around Louisiana are at flood stage but held back by levees. Backwater flooding is likely as waterways that flow into those rivers meet high water, he said, as is flash flooding.
At New Orleans, the spillway will keep the crest at about 17 feet.
The Mississippi will crest above that about May 22 or 23, as a rise works its way down from Arkansas City, Arkansas, Graschel said.
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McConnaughey wrote from New Orleans.
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