Without a dam on Amite, Corps would raise more than 4,000 homes

Without dam on Amite, Corps would raise more than 4,000 homes

October 23, 2023

Without big dam on Amite River, Corps would raise thousands of homes in Baton Rouge region

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An estimated 4,000 homes would be raised out of harm's way under a $1 billion elevation and flood-proofing program the U.S. Army Corps of Engineers is exploring as an alternative to a controversial dam proposed across the Amite River in St. Helena Parish, agency officials said.

In November, the agency's top brass authorized more money and time to study the voluntary program that would include flood-proofing nearly 390 businesses and other nonresidential structures as a potential replacement for the $1.3 billion Darlington Dam.

The dam would reduce water levels in a 100-year-flood — one large enough that it has a 1% chance of happening in any year — by an estimated 6 feet in Denham Springs, winning outspoken backing from Livingston officials.

The plan, however, has garnered fierce opposition in St. Helena and East Feliciana parishes because the dam would periodically flood up to 26,000 acres.

It has raised environmental justice concerns over its heavy impact on the parishes' Black residents who would have to be bought out. Corps officials acknowledged this week that the project has no benefit at all for those two parishes.

For the first time, agency officials this week provided a preliminary estimate for the scale of the alternative residential home-raising program, which, at 4,000 units, would amount to a few hundred homes fewer than what the census estimates was in the entire city of Denham Springs in 2021.

The program follows a growing trend over the past decade by the Corps to incorporate more of this kind of "nonstructural" option in public works projects instead of or along with its dams, levees, locks and canals, Corps officials and an outside flood plain management expert said.

In Louisiana alone, the Corps' flood protection and coastal restoration plans vetted over the past 10 to 15 years, including the new Amite alternative, are calling for a combined 19,000 structures to be elevated or flood-proofed. Most are part of larger projects that also build levees, dig canals or restore marshes. 

In the Amite River's case, the elevations and flood-proofing, which means businesses won't be raised but reinforced against high water, don't come with other public infrastructure or ecological restoration, according to early plans.

The shift away from the 3.6-mile-long, 86-foot-tall earthen dam proposed for the hamlet of Grangeville is already raising concerns for local leaders because the plan won't prevent floodwater from spreading across the land.

Fred Raiford, the East Baton Rouge Parish transportation and drainage director, and Clint Cointment, president of Ascension Parish government, questioned this week whether the elevation program would be a sufficient, overarching solution for chronic flooding in the 2,200-square-mile Amite River Basin, where their constituents remain jittery since the 2016 flood.

"I guess my point is that's a lot of money. I'm trying to figure out what the big picture is going to be for us, for our parishes and what that impact's gonna be," Raiford said.

Raiford said he receives calls from worried residents "every time it rains."

"There's got be a way for the Corps to look at these types of dynamics that we're dealing with and come up with a plan that does reduce the flood risk for people in the parish," he said.

The Corps officials' disclosure of the number of home elevations and Raiford's and other officials' comments came Tuesday during the first meeting of the newly reconstituted Amite River Basin Commission.

State Rep. Buddy Mincey, R-Denham Springs, sponsored legislative changes last year to alter the panel's membership and broaden its powers and management mandate.

Cointment, a new commissioner, as is Raiford, added that home elevations won't stop streets from flooding or prevent the drowning risk that flooding poses to drivers caught in high water.

"And so I see this movement and shift, and it concerns me because we've gotten out of projects that actually keep people from flooding and we're just raising the structures, but that doesn't eliminate all the other things that come with flooding, all the problems we deal with on a day-to-day basis," Cointment said.

The state commission oversees flood protection in the seven parishes that are part of the Amite River Basin in Louisiana. The panel is best known for its sponsorship of the Comite River Diversion Canal, which is now under construction after decades of bureaucratic and federal and state funding delays.

A big, but common number

The 4,000 home elevations, which is a preliminary estimate the Corps says will change as the plan is refined for public review this summer, matches other programs proposed recently by the agency in south Louisiana.

Calcasieu, Cameron and Vermilion parishes in southwest Louisiana are expected to see nearly 3,462 homes elevated, said Matt Roe, a Corps spokesman in New Orleans. Another 499 businesses and other nonresidential structures would be flood-proofed under that plan, which also calls for marsh restoration and other public works projects.

The Darlington Dam proposal itself called for more than 3,560 home elevations, plus flood-proofing.

The state's Road Home program after Hurricane Katrina dwarfed these proposals, however. Nearly $943 million was spent on almost 32,390 home elevations under Road Home, state officials said. Much of that work, however, also came along with the Corps' $14.5 billion revamp of New Orleans' levee system. 

Corps officials estimated the cost is about $200,000 to $300,000 per home, adding it would not require an out-of-pocket match by the homeowner but by the state. Other programs have spooled out over 10 to 15 years as money is available.

Homes would be elevated to the estimated height of the 100-year flood 50 years in the future, plus some additional height above that figure for wiggle room.

A 100-year flood has a 1% chance of happening in any year, but the estimated height of that flood tends to rise over time as development and other changes cut into an area's ability to hold rainfall runoff.

Only a selection of homes and businesses inside the 100-year flood plain that are more at risk of flooding — those susceptible to the more frequent 25-year flood — would be part of the elevation and flood-proofing program.

Under questioning from Mincey on Tuesday, Corps officials said they have not yet evaluated how easily the state's home elevation industry could handle the alternative plan for the Amite.

Matt Harding, production manager for one of the biggest home elevation companies in the state, Davie Shoring, said his company has nine to 11 elevation crews working, plus others that handle different phases of the work. They were able to finish 85 home elevations last year across the state.

He said the industry's ability to handle the work for the Corps' proposals in south Louisiana will depend on how quickly the agency starts the work. He estimated Louisiana companies could probably handle 1,000 to 1,500 per year at best.

"That's probably stretching it," he said, though he added that out-of-state companies also could pick up demand.

A little at a time?

In Louisiana, having the Corps of Engineers lead home elevations represents a shift from more common efforts through the Federal Emergency Management Agency's hazard mitigation program.

But Chad Berginnis, executive director of the Association of State Floodplain Managers, said the Corps has been doing home elevations since it gained the authority in the late 1970s to early 1980s.

Berginnis, whose group favors home elevations as a flood risk reduction option, said the projects have gained momentum since 2010 as the Corps has had to grapple more with environmental concerns and political opposition to public works projects with lots of impacts.

He added that home elevations can be more cost effective. They don't have the long-term operational costs of large structures. They also allow the agency to start reducing flood risk sooner, instead having to wait years for enough money to be amassed to build large public works projects.

The Comite Diversion suffered, in large part, from this problem.

"One of the things that I think could be a benefit is that, you know, whatever amount of funding you get a year, you can actually do 100% mitigation for at least part of your project area. You know, you don't have to wait for the entire system to be done to then get flood protection in that area," Berginnis said. "You actually can apply it as the funding comes in and at least have incremental protection."