Posted on 08/21/2016 5:27:22 AM PDT by fella
Trey Poirrier and Jerry Gravois stood in waist-deep floodwater near the St. Amant Fire Department Monday morning trying, unsuccessfully, to reach a relative’s waterlogged home.
Nearby, caskets were floating around the Methodist church. Volunteer boaters sailed by them with a rescued family of five, including three girls young enough to attend close-by Lake Primary School, also under water.
“The pictures and the videos don’t serve it justice until you get out here,” Poirrier remarked.
This is South Louisiana in August 2016 — people reduced to pleading for diapers in Central, whole neighborhoods wrecked in Baton Rouge, and most of Denham Springs buried under water and debris.
There have been other visions for the Amite River Basin — the main culprit in the catastrophe. As early as the 1970s, officials talked about drainage improvements, and their voices got louder after the horrific flood of 1983.
A canal would redirect high water from the Comite River through Baker and into the Mississippi River. A dam and reservoir would hold back the flow of the Amite in East Feliciana and St. Helena. Levees would protect Denham Springs.
Three decades later, Ascension Parish has built several drainage pumps, levees and floodgates, but the big, federal projects have been abandoned or left incomplete.
Southeastern Louisiana, at present, has thousands of families digging out of their mud- and water-ruined homes, a gaggle of government officials calling each other incompetent and a flood-control structure with no canal to control.
No one has suggested that the proposed Comite River Diversion Canal or the Darlington Reservoir would have prevented the flood. But the canal alone could have saved up to a quarter of the homes damaged in the basin, says the former president of the commission that oversees the project.
Following the 1983 flood, the U.S. Army Corps of Engineers drew up several designs to improve drainage along the Amite and Comite rivers. There were some early discussions of putting levees along the Amite around Denham Springs, but the plan was deemed impractical, said Dietmar Rietschier, executive director of the Amite River Basin Commission.
Instead, officials focused on digging the canal and creating a reservoir on the Amite near Darlington, by the Mississippi state line. However, that project has also since been abandoned.
“It was always the idea to have these two projects working together complementing each other,” Rietschier said. “It would have benefitted (the region) by lowering the flood stage — to what degree, I don’t know.”
The Corps is currently studying whose homes the canal may have saved. They've previously investigated the effect the diversion would have during smaller storms, but nothing the size of the recent one.
The basin, and the rain
The Amite River itself emerges from Mississippi and forms the parish lines between much of East Feliciana, East Baton Rouge and Ascension on one bank and St. Helena and Livingston on the other. The Comite and Bayou Manchac are two of the bigger waterways that drain into the Amite, which eventually empties into Lake Maurepas.
Last week, as in 1983, the Amite became swollen with water, beginning a cascade of floods in the rivers, bayous and ditches farther upstream, a phenomenon known as backwater flooding. But while the similarities between 1983 and the 2016 floods are striking, there are several reasons for the difference in magnitude.
First were the circling storms that fed the floods. Barry Keim, Louisiana state climatologist, said nine weather stations in the region exceeded a 1,000-year rainfall event, which roughly equals 21 inches of rain in 48 hours. Most of that happened in the North Baton Rouge area and Denham Springs.
“It’s really no wonder that the floods were as catastrophic as they were,” Keim said.
A 1,000-year rainfall event is one that has one-tenth of a percent chance of happening in a given year. In contrast, the more often-cited 100-year rain event has a 1 percent chance of happening in a given year. Despite the terminology, these events don’t necessarily happen only once every 100 or 1,000 years. In terms of probability, one storm doesn’t affect the chances of another happening, just as one flip of the coin doesn’t affect the next.
Todd Baumann, data chief for the U.S. Geological Survey's Lower Mississippi-Gulf Water Science Center in Louisiana, said it’s a safe bet much of the flooding is beyond a 100-year event.
“We had 12 river gauges across the state that exceeded the highest events we’ve ever seen, so we’re in completely uncharted territory,” Baumann said.
According to National Weather Service data, every gauge on the Amite River from Darlington to French Settlement broke an all-time record.
"We don’t even know yet exactly how much it was. We’re still working those numbers out,” Baumann said.
Compounding the damage is the growth of the communities along the Amite.
They have exploded in population in the intervening 33 years, putting more people and homes in the path of the water. The number of inhabitants in Livingston and Ascension parishes has more than doubled, from about 109,000 combined in the 1980 census to more than a quarter-million last year.
And now many of those people are asking what could have been done to save their homes and businesses.
Diversion canal
Even before the floodwaters hit their highest marks, local officials began questioning why the Comite Diversion Canal remains unfinished.
The canal is supposed to begin at the Comite near the intersection of Lower Zachary Road and La. 67 and run westward between Baker and Zachary. The canal would take water from the Comite — as well as from Cypress and White bayous — before emptying into Lily Bayou, which flows into the Mississippi River. Upstream of the confluence with the Amite River, the canal would also reduce flooding in Livingston and Ascension Parishes, though to a lesser extent.
It would be 20 feet deep and 300 feet across — wide as a football field, said state Sen. Bodi White.
“That’s a lot of water,” he remarked.
The Corps has estimated that the canal could reduce the height of the Comite River near Central by more than 7 feet in a small-scale flood, and by 5½ feet for a "100-year" flood. However, there is no model for an event the size of what Louisiana just experienced.
In Central, 90 percent of the homes are flooded, said Mayor Jr. Shelton, who challenged those involved with the diversion canal to come out to his city and see people lining up for food and desperate for toiletries.
“How many people’s lives ruined does it take to get the solution?” he asked. "It's disgusting."
The diversion would have the greatest impact on people in places like Central, Baker and Zachary, though it would make a measurable difference as far south on the Amite River as Port Vincent, the Corps has reported in the past.
That far downstream, the Amite also receives drainage from other bodies of water, including Bayou Manchac. A onetime trade route in Louisiana's early days, Manchac receives much runoff from growing south Baton Rouge, as well as from parts of expanding Prairieville in Ascension.
Toni Guitreau is both the executive secretary at the Amite River Basin Commission and the mayor of French Settlement, just down the river from Port Vincent.
“We have homes flooded that have never been flooded,” she said.
Guitreau said the canal would have helped prevent damage in her town.
Even if it’s just an inch … if it’s your house, that counts,” she said.
Most engineering solutions for flood control are based on a 200 year event. even those solutions would be insufficient for a 1000 year event
Many Corps projects have been blocked by the environmentalists. It goes back to the blocking of the erection of flood control gates at the Rigolees that could have done much to limit the Katrina damage.
I’m from south west louisiana and for at least 20 years we’ve buried people in concrete lined graves with a concrete cover. It’s very much a creole Catholic area and the only above ground graves are the communal crypts.
That approach is good overall, but not so good if you happen to be one of the unlucky ones for whom the preparations are insufficient.
That said, it seems like an interesting area for some research would be ways to design houses so that they could withstand shallow, slowly flowing floods. It might be possible to design a sealing and structural system that could withstand a shallow flood. In cases like the mess in Louisiana such a system could have saved a lot of homes from damage.
[[rotting coffins popping out of the soggy soil is alarmist nonsense ]]
But they do pop out of the ground .
I grew up on the other side of the river .
I remember hearing and reading about caskets popping out of the ground many times during floods .
Still, I suppose there has to be some truth to the legends ... All I know is what the boozy tour guide told us.
Just curious, has anyone accused Trump of blowing up a Levee yet?
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