NEW ORLEANS - From rain barrels outside homes and planter boxes on sidewalks to ditches filled with vegetation, community-led projects in New Orleans are helping the city to cut flood risk and improve water management as climate change fuels more extreme weather.

One day in April, Mr Rollin Garcia – who owns Bullet’s Sports Bar in the Seventh Ward neighbourhood – showed off a planter box outside his bar that can help divert hundreds of litres of water during storms by holding rainfall, easing pressure on the city’s sewers.

“A lot of people are asking for this and the (rain) barrels,” said Mr Garcia, standing next to the planter box that was built with support from Healthy Community Services, a non-profit group.

When Hurricane Katrina devastated large areas of New Orleans and the Louisiana coast in 2005, many residents were left struggling amid a widely criticised disaster response effort.

Today, community groups are taking the reins and boosting the city’s storm resilience by planting trees, using rain barrels, and creating bioswales – ditches or channels lined with plants to help filter rainwater – among other green projects.

Despite these growing efforts, each hurricane season still brings with it the risk that the city’s residents – particularly those without the means to evacuate – could again end up stuck in their homes without power, surrounded by rising floodwaters.

As New Orleans braces itself for this year’s season, which runs from early June until late November, scientists say climate change is making such storms more intense.

Hurricane Ida, which struck Louisiana in August 2021, for instance, was one of the harshest hurricanes to hit the state since Katrina, scientists said.

The community-driven projects in New Orleans are not just practically useful during and after extreme weather events, but also benefit neighbourhoods by providing “ecosystem services”, according to a new report.

A set of “green infrastructure” projects in a handful of New Orleans neighbourhoods now generates more than US$19 million (S$25.6 million) worth of annual benefits ranging from flood regulation to a reduction in noise and heat exposure, the May report noted.

The study was released by Earth Economics, a research group, and Water Wise Gulf South, a collective of local organisations working on such issues.

Ms Angela Chalk, executive director of Healthy Community Services, a Water Wise partner, said her group and others were seeking to keep the momentum going.

“I can’t explain how fascinating it’s been to (see)... how residents have taken the ownership in seeing that this is our neighbourhood,” she said.

Water-wise

The idea of “living with water” – rather than fighting it – took some getting used to post-Katrina, said Mr Jeff Supak, executive director of Water Wise Gulf South.

“This is kind of a new way to manage stormwater for a lot of people,” he said. “People really, in New Orleans, they want the water out as quick as possible... but we know that our infrastructure system can’t do that right now.”

New Orleans is effectively shaped like a giant bowl, and even with post-Katrina improvements in levee systems and building elevations, the city’s contours make it tough to remove large quantities of water once they build up.

As of 2023, community groups have planted more than 770 trees, installed 146 rain barrels, and implemented at least 110 other green infrastructure projects to instead soak up more of the water, the Earth Economics/Water Wise report found.

The efforts have helped add more than 715,443 litres of stormwater retention capacity to several city neighbourhoods.

Near her house in the Seventh Ward, Ms Chalk pointed out a bioswale featuring vegetation taller than herself, and rain barrels at nearby homes.

“What I can tell you is when we have these intense rainfalls, neighbours notice the difference in this block not having water as compared to the other blocks,” she said.

Across the street from her house sits a solar-powered “ECO Bench,” which helps measure precipitation to track neighbourhood-specific rainfall. It also provides a charging station, a source of sustainable energy in case of emergency.

It was designed and built in part by Groundwork New Orleans, a community development group, with support from Ms Chalk’s organisation and funding from the National Fish and Wildlife Foundation.

“We need both the gray infrastructure – the pumps, the pipes and the drains – and the nature-based solutions,” she said. “We know that these nature-based solutions and interventions work.”

Other US cities, from Portland in Oregon to Providence in Rhode Island, have also been investing in green infrastructure.

New York City, for example, has saved an estimated US$1.5 billion by incorporating green infrastructure into its stormwater planning. This has cut spending by about 22 per cent compared to a “gray-only” approach, the Earth Economics/Water Wise report said.

New Orleans officials have also been working to boost resilience post-Katrina with green infrastructure projects such as permeable pavement, which helps water flow into the ground instead of onto city roads during storms.

In addition to improvements in the area’s levee systems, New Orleans since Katrina also has lifted the height regulations for many buildings beyond federal requirements, said Mr Austin Feldbaum, the city’s director of hazard mitigation.

“It would take a catastrophic structure failure (and) a really heavy rainstorm to produce a flood that would cause widespread flooding of homes today because of the building code work we’ve done and the investments in home elevations and things like that,” he said.

Community input

Another project Ms Chalk touts is a park in development on North Claiborne Avenue, a thoroughfare that cuts through several largely black neighbourhoods.

The site now helps manage 132,490 litres of water during storms, and is ultimately slated to house a solar-powered weather station that would help measure precipitation levels and provide real-time heat alerts.

“This side of Claiborne no longer floods because of the water that this bioswale is managing,” Ms Chalk said, explaining that residents chose the site themselves.

“Nothing that we do is without residents co-developing, co-designing, and co-owning (it).”

Water Wise helps organise tours, demonstration projects and workshops to raise awareness and foster ideas on where to build.

Largely black communities, which frequently bear the brunt of climate-related impacts, need a prime seat at the table when it comes to making resilience decisions, Mr Supak and Ms Chalk said.

“Especially in communities of colour,” people should “respect the people that live in communities and work with those residents because they know their communities best than someone else,” Ms Chalk said.

“We don’t need another saviour in the African-American community. We need people to understand our needs and work with us to resolve the issue.” THOMSON REUTERS FOUNDATION