Anti-Flooding System Set To Protect New Orleans
HIGH WATERS IN THE HEARTLAND
AS the Mississippi River surges southward, with flood levels at record highs in the Midwest, many in this city of historic floods believe the strength of the river's current will be greatly diminished by the time it meets the Gulf of Mexico.
``At this time I'd have to say it doesn't pose much of a threat to us at all,'' says David Wagner, managing director of the Port of New Orleans, which daily handles more than 20,000 tons of general cargo shipped in from ports all along the river.
``We generally think that by the time the flood waters get here, they'll be mostly diverted into a number of different waterways and tributaries and [will] not be nearly as strong as they've been up north,'' he adds.
Dwayne Jensen, a lock operator with the United States Army Corps of Engineers' Algiers Lock, located here along the river's edge, agrees: ``This is a case where the system will slow down Mother Nature,'' he says. ``We have an incredibly diverse system of locks and channels and spillways that are specifically designed to divert high-level waters like this. Right now, even with it being at a flood-stage level, we're in pretty good shape.''
Floodwaters from St. Louis to St. Paul, Minn., this week have reached their highest point in nearly three decades, forcing the closing of a 500-mile stretch of the river as it snakes through Minnesota, Wisconsin, Iowa, and Illinois.
The floods, bolstered by heavy rains throughout the Midwest, have destroyed more than 300 barges and some two-dozen towboats along the river's edge. Boaters have also been warned to stay off the river because of fast-traveling tree limbs, boards, and other debris that are being swept along the longest river in North America.
But even though the river's crest is expected to pass the 22-foot mark near Davenport, Iowa, this weekend - reaching the 22.5- foot record of 1965 - maritime officials in southern Louisiana believe a complicated system of levees, diversions, and spillways will rob the flood of its potency here.
``Even for the biggest of floods, we have a system that gives us great protection,'' says Mr. Wagner of the Port of New Orleans.
``In addition, the water volume that is coming through the river up north right now is also going through a part of the river that is relatively narrow, which makes it even more powerful. By the time it reaches southern Louisiana, and the mouth of the river to the Gulf of Mexico, it is much wider here, and that weakens floods too,'' he adds.
The flooding should be limited to the upper Mississippi basin, according to George Cry, of the National Weather Service's river forecast center in Slidell, La.
The lower basin is fed by the Missouri, Ohio, Tennessee, and Arkansas rivers. Those rivers are at seasonal levels or below, he said. And as the [Mississippi] water is flowing downstream, ``it is not creating a massive flood wave,'' he adds. A small rise is expected later from about Cairo, Ill., to Vicksburg, Miss., and an even smaller rise is forecast down to New Orleans, he says.
The intricate flood-water diversion system, constructed by the US Army Corps of Engineers, blankets the entire lower Mississippi River basin from the vicinity of Vicksburg to the Gulf Coast, and includes the bayous of southern Louisiana, the deep Delta of Mississippi, and dozens of smaller tributaries and canals in between.
Far stronger flooding in 1927, which caused the deaths of more than 200 people, provided the impetus for today's system.
Beginning in the first years of the Great Depression, the federal government built modern spillways and stronger levees, which are designed to channel a flood twice as forceful as 1927's. Because of this, many people in New Orleans view floods from the river as phenomena of the past.
But it is that same history, says Lester Sullivan, a professor of history and chief archivist at Xavier University here, that should give anyone in these parts pause: ``Almost all of New Orleans is under the sea level, and it continues to drop further and further below the sea level each year. In fact, one of the great ironies of this city is that the highest ground in New Orleans is the river itself.''
Because of its precarious perch that is surrounded by the river, Lake Ponchartrain, and the several bayous, the city of New Orleans must take any water threat seriously, Sullivan adds.
``But of far greater danger for us is the river surging in the opposite direction, from a hurricane blowing up from the Gulf of Mexico,'' he says.
``There have been a number of studies showing that the floods we could get from that kind of pattern could drown this city. But it's not anything we like to think about for very long.''