Slow-moving Isaac forces thousands to flee homes

NEW ORLEANS – Isaac continued its slow march across Louisiana on Thursday as rising floodwaters forced tens of thousands of residents to evacuate and officials launched a “controlled” release of water from a storm-stressed dam along the border with Mississippi. At least one death was reported.

As evening approached on another soggy Gulf Coast day, hundreds of homes remained underwater and thousands of residents scrambled to emergency shelters. At least 500 people who had gambled on riding out the storm were rescued by helicopter or boat. About a third of the state remained without electrical power, even as the once-mammoth Isaac was downgraded late Thursday to a tropical depression.

Although levees protecting New Orleans held fast, sparing the city significant flooding, officials warned that the danger had not passed. Mayor Mitchell Landrieu lifted a dusk-to-dawn curfew but implored residents not to leave their homes on irresponsible sightseeing trips.

The rains and winds eased Thursday, but rural and suburban areas remained firmly in Isaac’s watery grip. Rivers across Louisiana continued to rise and many were predicted to reach historic flood levels of 20 feet or more before receding. In some places, entire communities were evacuated, including Kentwood, La., with a population of 2,200.

In a region familiar with nature’s mayhem, survivors of past storm systems with names like Gustav, Ike and Katrina kept one eye on the sky and the other on rising waters, as meandering and unpredictable Isaac dumped as much as 16 inches of rain in some places. Downed trees and power lines continued to block roadways, and cars and trucks plunged headlong into standing water.

Each of southern Louisiana’s numerous parishes, or counties, faced its own misery. For some, tornado watches loomed throughout the day. And in storm-thrashed Plaquemines Parish, officials began work on a levy breach to prevent the structure’s failure.

But the day’s most tense drama occurred 60 miles northwest of New Orleans, where the Lake Tangipahoa dam – located just across the Mississippi border – showed signs of weakening.

Officials ordered 60,000 residents within half a mile of the swelling Tangipahoa River to evacuate as crews with backhoes, bulldozers, pumps and other equipment rushed to the 2,300-foot-long earthen dam at Percy Quinn State Park. As workers conducted the “controlled breach,” a Louisiana National Guard helicopter hovered overhead, providing a minute-by-minute update of the dam’s condition.

“You can see the water spilling over,” Louisiana Gov. Bobby Jindal said at an afternoon briefing after a flyover of the dam, adding that officials did not think the dam had been compromised.