NEW ORLEANS, (Reuters) – Torrential rain dumped by Hurricane Isaac threatened to burst a dam in Mississippi yesterday, triggering the mass evacuation of local residents, while large areas of the region were still flooded and without power but getting ready to mop up.
Isaac, which was downgraded to a tropical depression yesterday, did little damage to New Orleans, where stronger barriers were installed after Hurricane Katrina in 2005. Only one fatality linked to the storm has been confirmed so far.
But it produced a soggy mess across widespread areas of the U.S. Gulf Coast and could still bring heavy downpours and flooding before moving into the central United States – where rain is badly needed – over the next few days.
Some 700,000 homes and businesses in Louisiana and Mississippi were still without power on Thursday, down from about 1 million overnight. As winds subsided, crews were able to start assessing damage.
While New Orleans and the coast got started with cleanup, new worries developed about a potential failure of Lake Tangipahoa Dam in Mississippi’s Percy Quin State Park.
Authorities ordered the immediate evacuation of tens of thousands of residents in nearby communities in Louisiana and Mississippi as a protective measure.
The earthen dam, in Pike County, is about 100 miles (160 km) north of New Orleans. It was damaged, but not breached, Wednesday night’s tumultuous downpours.
Heavy equipment and pumps were brought in to start a controlled water release to the Tangipahoa River, relieving pressure on the dam.
“Every precaution is being taken to protect the safety of the people and property,” said Mississippi Governor Phil Bryant.
Ken Graham, forecaster with the National Weather Service in New Orleans, said the Tangipahoa River near Kentwood – hometown of pop singer Britney Spears – is already 14 feet (4.3 metres) above flood stage and is expected to rise to 16 feet (4.9 m) by this morning.
“That takes it to a pretty big flood event, and that’s just from the rain,” he said.
Additional heavy rain is not expected as the remnants of Isaac move away, but the National Weather Service said the dam “may potentially fail” and is keeping a flash flood watch in effect for Pike Country through 5 p.m. ET (2100 GMT) today.
State officials were at odds about the risks posed by the dam. Louisiana Governor Bobby Jindal warned of potential “record flooding” downstream, while officials in Mississippi downplayed the possibility of a dangerous water release.
“Even if that dam would have a catastrophic break, the flood plain in Pike County would be able to handle it, so it would not significantly affect the river,” said Greg Flynn, spokesman from the Mississippi Emergency Management Agency. “They don’t expect any wall of water to go down the river.”
DAMAGE ASSESSMENTS
In areas struck earlier by Isaac, the process of checking for damage and restoring halted operations began.
The oil and gas industry in the Gulf of Mexico has so far reported no major storm-related damage to infrastructure although one Louisiana refinery has had flooding.
Energy production was expected to start ramping up again, after nearly grinding to a halt as Isaac closed in on Louisiana on Tuesday. Benchmark Brent crude was little changed in Thursday afternoon trading at about $112.75 a barrel.
Multibillion-dollar defenses built to protect New Orleans itself, after it was ravaged by Katrina almost exactly seven years ago, passed their first major test, according to the U.S. Army Corps of Engineers. “The levees worked,” Jindal said.
Among the items spared in the storm were thousands of bags of green coffee stored in New Orleans warehouses that had sustained damage during Katrina.
“No major damage to the buildings and no damage to stored product,” Allan Colley, president of Dupay Storage and Forwarding, said in an email.
Dusk-to-dawn curfews, designed to help prevent any repeat of the looting that occurred in New Orleans in the days after Katrina struck in 2005, were lifted on Thursday.
Only about a dozen looting-related arrests were reported in the city by Thursday morning but the streets were unusually quiet, still littered with downed branches, fallen trees and pieces of roofing material.
In the historic French Quarter, a few people were out taking down the boards they had nailed up over store windows. Officials urged patience and good humor during the clean-up.
