How a $3.7bn construction project aims to protect communities near New Orleans from hurricanes

Image supplied by USACE

The devastation wrought by Hurricane Katrina on New Orleans and the wider Gulf Coast in 2005 lives long in the memory.

The deadly hurricane caused 1,836 deaths and damage estimated between US$97.4 billion to $145.5 billion.

While that was the worst hurricane to hit the region in living memory and the costliest ever to hit the United States, the area was also battered by Hurricane Isaac in 2012 and Hurricane Ida in 2021. Isaac in particular caused tens of billions of dollars’ worth of damage in Louisiana.

Against that backdrop, the $3.7 billion West Shore Lake Pontchartrain (WSLP) Hurricane and Storm Damage Risk Reduction project could pay for itself in relatively short order, although costs on the project have risen significantly (see below).

Image: USACE

Overseen by the US Army Corps of Engineers (USACE), it aims to provide over 60,000 residents across three parishes – St. John the Baptist, St. James and St. Charles Parish – with a 100-year level risk reduction.

The work involves building a massive, 18-mile-long levee system in remote locations and often on challenging terrain. The first contracts were awarded late last year and work is expected to carry on through to late 2027.

To provide that 100-year level risk reduction, US Army Corps of Engineers (USACE) and its team has made calculations using specialist computer software called ADCIRC to run a suite of 37 different storm types through the project area.

The calculations give surge and wave statistics to help predict how the levees will perform, says Bradley Drouant, USACE senior project manager, New Orleans District.

As things stand, USACE has already awarded or is close to awarding eight contracts that account for 13.8 miles of the 18-mile levee system.

Drouant says, “The first levee construction contract, WSLP-110 near Garyville, was awarded December 2022. WSLP-107 was awarded in March 2023. Construction on the third and most eastern levee reach, WSLP-101a, was awarded in April 2023. The fourth and fifth levee reach construction contracts, WSLP 108 and 104 respectively, were awarded in August 2023. WSLP-102 and WSLP-106 were awarded in September 2023.”

Another contract, WSLP-105 was awarded the end of September (see box below).

Image supplied by USACE

Those awards follow the construction of nine “land bridge” access roads from existing state highways and the Interstate Highway 10 (I-10) to the future levee alignment.

Those access roads are essential because the marshy, sparsely populated areas where construction is underway makes for difficult working conditions.

“A primary difficulty of the WSLP project is the location,” says Drouant.

“The conditions of the marsh make it especially difficult to mobilize equipment and to complete construction.

“The accessibility of sites for workers, materials, and equipment is also a challenge.

“However, it is one we are prepared for by awarding a $16m contract to provide ‘land bridge’ access roads through the marsh. We overcome the challenges of this project through preparation and planning.”

Other works in advance of the levee construction included two sand placement contracts in the WSLP-101/102/103 reaches, pile load test contracts, three stockpile contracts for sand and clay, and multiple mitigation bank awards.

Bradley Drouant

USACE expects to continue awarding levee construction contracts through autumn 2024.

Meanwhile, efforts are underway to design the project’s western tie-in levee, which will link with Louisiana’s Maurepas Diversion project.

The Maurepas Diversion is a swamp mitigation feature of the WSLP project to compensate for What USACE calls “unavoidable impacts” to swamp habitat.

Future work by USACE includes two additional levee contracts, two floodgate contracts, and a contract for two major 2,000 cubic feet per second (CFS) pump stations in St. John the Baptist and St. Charles Parishes.

The Coastal Protection and Restoration Authority and the State of Louisiana are expected to award three levee reaches and the Maurepas Diversion as a single contract. There is a separate Corps contract planned to provide risk reduction in St. James Parish.

Rising costs

While the entire project originally had a budget of $760 million allocated to it (based on 2014 economic conditions), USACE announced earlier this year that costs have risen considerably.

In July this year, it set out reassessed project costs including the requirement for an additional $1.27 billion to deliver WSLP to its authorized levee elevations and to complete the system’s pump stations and drainage structures.

On top of that, the USACE said it would need another $1.7 billion for environmental impact mitigation efforts and future levee lifts to ensure that the authorized level of risk reduction is maintained throughout the project’s 50-year design life.

Col. Cullen Jones, New Orleans District Commander, said, ““An increase in project cost has become common throughout the nation, for not only Corps of Engineers constructed projects, but also for goods and services due to ongoing supply chain issues.

“We will continue to press forward in completing the ongoing work as well as awarding new construction contracts while simultaneously pursuing every option for securing additional funds required to deliver this system.”

Lasting legacy

Despite those inflating costs, the project team involve are hopeful that their work will leave a lasting legacy in the area.

Drouant says: “Personally, I am ecstatic to have the opportunity to contribute to this project.

“I am very pleased with the entire team of our non-federal sponsors (Coastal Protection and Restoration Authority and Pontchartrain Levee District) and the personnel here at the New Orleans District. The significant effort and coordination the team has contributed over the years has made the award of these contracts possible.

“The project delivery team is composed of highly motivated individuals eager to provide a finished project to the citizens of St. John the Baptist, St. James, and St. Charles Parishes to help reduce the risk to their lives, property, and prosperity.”