Challenge
After Hurricane Katrina, the Pontilly neighborhood was suffering. Subject to frequent flooding, this neighborhood, and the city of New Orleans, with the help FEMA worked together to devise a solution.
After decades of fighting persistent floodwaters with pumps and walls, the City of New Orleans, and the New Orleans Redevelopment Authority (NORA) are using a new approach in the city’s Pontilly neighborhood that works with floodwaters, not against them.
Solution
The traditional method of dealing with floodwaters is to pump the water away from homes and businesses. These methods often cause soil to sink, damaging sidewalks and home foundations while overtaxing the drainage system beyond its capacity.
In 2008, Pontilly neighborhood homeowners brought forth ideas and designs for a new flood management system to NORA and the city. The new design would hold water where it falls, giving the existing drainage system time to follow its natural drainage process without flooding the neighborhood. This new method redirects water in a beneficial way for a whole community approach to mitigating natural flooding hazard events.
“The homeowners and community within Pontchartrain Park were the biggest advocates for the development of the project,” said Stormwater Program Manager of the Department of Public Works at New Orleans City Hall, Meagan M. Williams, P.E.
In 2010, with funding from FEMA’s Hazard Mitigation Grant Program (HMGP), the City and NORA broke ground on the $15.5 million Pontilly Neighborhood Stormwater Network.
Administered by the state, HMGP awarded funds may pay up to 75% of the eligible cost with a remaining 25% match absorbed by the applicant. HMGP provides funds to states, federally recognized tribes, local governments, and eligible private nonprofits following Presidential disaster declarations. Projects funded by HMGP must reduce or eliminate the losses from future disasters, and projects must provide a long-term solution to the problem
The Pontilly project reduces flood risk in Pontchartrain Park and Gentilly Woods by slowing and storing stormwater. The improvements combine a network of stormwater storage areas on lots left vacant after Hurricane Katrina, dubbed “stormwater parks.” In addition, bioretention cells (street basins), created at intersections, and bioswales (vegetated channels) placed between curbs and sidewalks to store water runoff until the drainage system could support more water. This has the added benefit of removing pollutants from runoff and recharging groundwater. Replacing parallel parking spaces with porous pavers to serve as inlets and provide subsurface storage for additional groundwater penetration, improvements to the Dwyer Canal rounded out the endeavor, funded by a $3.5 million U.S. Department of Housing and Urban Development (HUD) National Disaster Resilience Award.
“One of the challenges during development was to determine how to create a variety of features throughout a large neighborhood that all functioned cohesively with an aging infrastructure system,” said Williams. “Because of the location and proximity to railroads, utility services and sensitive natural habitats, such as the bald eagle nests, coordination throughout the design was imperative.”
The stormwater project has relieved the overburdened drainage system, slowed land subsidence, and improved water quality – all while beautifying historic and diverse neighborhoods. The green spaces also allow for cooling the surrounding areas by increasing vegetation. In addition, the project provides more walkable area for residents.
Since the development’s completion in April 2021, the neighborhood has remained flood-free. “There have been many rain events that took place throughout the construction of the Pontilly project,” Williams said. “In June 2020, the first large rainfall event took place. Previously, in an event of this size, there would be significant standing water in the street, potentially damaging cars and possibly entering homes. The bioswale along the Bartholomew Golf Course, which holds approximately 900,000 gallons of water, was completely full. During Hurricane Ida, there was minimal standing water in the street, significantly reducing the impacts of the hurricane.” This is a huge improvement from Hurricane Katrina, when between 10 - 12 feet of water flooded Pontilly.
Homeowners are excited about the changes they see to their neighborhood and the safety it brings them. Actor Wendell Pierce (HBO's "The Wire" and "Treme"), a long-time resident of the Pontilly neighborhood and spokesperson for change, posted on Twitter, “EUREKA IT WORKS! Pontchartrain Park has returned to its green glory. The Pontilly Stormwater Project, of retention ponds & management of the rainwater flow, worked. I had my doubts. The water is gone.”
Peace of mind is an invaluable commodity for the homeowners in the area. Less flooding means less money spent on repairs and cleanup with an added benefit of increasing property values and making the community whole again for the first time since Hurricane Katrina.
Key Takeaways
Hazard Mitigation has grants to fund projects before and after a disaster: