clock menu more-arrow no yes

Filed under:

Why New Orleans's Back-to-Nature Experiment in Flood Control May Revitalize a Neighborhood

New, 3 comments

New Orleans was shaped by the river that carves and curves its way through the surrounding swamps and marshlands. Over time, as the city and government has attempted to tame the water using a system of levees and concrete infrastructure, manmade solutions have shown they often exacerbate flood control issues. A new development plan meant to address these issues charts a new course; by working with, instead of against, nature, it aims to provide not just a solution, but an opportunity.

The Gentilly Resiliency District offers a new way to think about resiliency, and its designers hope, a model for cities worldwide. A network of new parks, greenways, and infrastructure built in a working class neighborhood next to Lake Pontchartrain, the project seeks to simultaneously safeguard the area from flooding by introducing natural methods of water control, while beautifying the neighborhood and serving as a catalyst for redevelopment.

"The underlying aspect of this plan is helping the ecosystem and improving the health of the environment," says architect David Waggonner of Waggonner & Ball Architects, whose firm designed the district for the city. "It's the shining opportunity to become an ecological model of urbanism for the world. The idea is that the city and nature grow and come back into alignment. It's a fascinating opportunity to put some things right that we got wrong."

The Gentilly Resilience District is a long-term proposal; the $141 million Housing and Urban Development (HUD) grant the city won, which will be supplemented with city bonds and FEMA funding, will fund a project that may not be finished until 2022. But considering the investment in resources and ambitions this project represent, that time frame seems reasonable.

The proposed retrofit of this neighborhood's dated drainage system represents nothing less than a reconsideration of how New Orleans thinks about water. In the past, pumping stations and concrete infrastructure moved and dispersed the water that came from big storms, an over-engineered, one-way solution that created an "addiction to pumping," according to Waggonner, that's caused the land to sink. Jeff Hebert, the city's Chief Resilience Officer, has said New Orleans has learned over time that a balanced, integrated water management system, that relies on pumping as well as green infrastructure, is needed.

Gentilly was picked as a pilot in large part because it doesn't look like other parts of New Orleans. A different vibe than the historic districts to the south that many associate with the city, this former patch of swamp and marshland on the edges of the city was transformed into a suburban development through the use of modern drainage systems and levees in the '50s. By draining the swamp, and continually pumping and removing water, the land has sunk eight to nine feet below sea level, creating a landscape that requires more pumping, as well as unsteady soil that warps roadways. Think of the former swampland as a sponge; when you remove the water, it shrinks. It's a different landscape, and building homes like you would upland doesn't work.

The theory of the Gentilly Resiliency District, according to Ramiro Diaz of Waggonner & Ball, is to reduce subsidence through natural measures. By designing passive solutions that allow the land to absorb the water, the team hopes to develop a back-to-nature approach that can be replicated in other New Orleans neighborhoods, such as Lakeview and Lake Vista, as well as cities and towns across the globe facing similar issues.

"Weak soils require strong governance," says Waggonner. "It's about controlling the groundwater level in these marsh-like landscapes, and you need someone to look out and watch how it's developed."

The project, itself a series of smaller measures, suggest lining the neighborhood with a new network of pedestrian and ecological corridors. Medians will be turned into blue and green corridors, some of which will use swales, tree canopies and permeable sidewalks to soak up water. The Mirabeau Water Garden, a new retention pond, will be landscaped and turned into a public recreation facility. Walls to the drainage canal will be removed and replaced with parks and entrances, beautifying and opening the waterways for boaters and recreational use.

Excess water will be directed through natural channels and absorbed into the soil; dirty runoff will even be cleaned by the native plants lining the ground. This plan will also provide incentives to homeowners to invest in small-scale flood control measures, part of a holistic response meant to involve the city and local citizens.

But more than just fixing water flow, the scheme seeks to become an economic catalyst. New green space, open waterfronts, and more parkland and plantings makes the land more attractive and stimulates growth. Waggonner calls it a great civic catalyst that can give the area a new identity.

"The question architecturally for New Orleans is a question of density," says Waggonner. "When we prioritize trees and canopy and parkland, it creates a cluster of human activity and can help redevelop the area."

Waggonner, who has spent a lot of time consulting with and talking with colleagues in the Netherlands, who have their own deep-rooted experience finding solutions to working with rising sea levels and low lands, believes they're working on an issues faced by cities everywhere. But the city can't cut-and-paste Dutch solutions or import canals. The Gentilly Resilience District is a very local solution to a common problem, one that its proponents hope can make a big difference.

"With climate change projections, we only see more water coming," says Hebert. "This is a national issue. It's not, 'woe is New Orleans, another Katrina might wipe it away.' Rising sea levels is an issue for Baltimore, Boston… many more will have to confront this issue."

What You Need to Know About the Gentilly Resiliency District [Curbed]