Maribou Water Gardens

Over 10 years later, New Orleans is still recovering from Hurricane Katrina and the devastating effects of the Levee failures. That disaster proved to the world that building walls and pumping out water is not a long term or permanent solution. Water must be managed on site, with features such as permeable pavement, rain gardens, cisterns, and underground storage tanks. It takes projects installed throughout the city to protect it when a large storm hits. One of the projects New Orleans is working on to help low lying neighborhoods is the Maribou Water Garden.

The Maribou Water Garden was part of the Greater New Orleans Urban Water Plan. Greater New Orleans Inc. developed the plan in 2010 to address the challenges brought by their climate which drops an average of 60 inches of rain annually. The garden project is changing the way New Orleans thinks about water. Instead of pumping it out and blocking it with levees, they are keeping it on site. The attitude change is necessary because pumping and levees alone cannot project the city. It only creates more problems like subsistence when the ground begins to sink from the excessive pumping. 

 Subsistence problems created by excessive pumping (chart courtesy of nola.gov)

Subsistence problems created by excessive pumping (chart courtesy of nola.gov)

Along with hiring a new Resilience Officer, New Orleans has also created its first Resilience District. The Gentilly Resilience District, located in the Filmore neighborhood, is where the Maribou project will be constructed. The 25 acre vacant site was donated to the City by the St. Joseph Congregation. The congregation is supportive of the project because they feel it will shift the way "humans relate with water and land." 

 How the Maribou Water Garden will look after a 10 year storm event (image courtesy of nola.gov)

How the Maribou Water Garden will look after a 10 year storm event (image courtesy of nola.gov)

The design of the Maribou Gardens includes diversion and temporary storage of rainfall up to 10 million gallons. The sandy soils will help to infiltrate and clean the water as well. The site will serve as an educational center and outdoor classroom. The 25 acre site is expected to capture 140 acres of runoff, create 745 acres of improved flow, and increase the pumping capacity of station #4 by 2,900 acres. All the water that stays on site allows for more room in the current system to capture runoff. 

 (Site plan for the Maribou Water Garden (plan courtesy of nola.gov)

(Site plan for the Maribou Water Garden (plan courtesy of nola.gov)

The project budget is $12.5 million dollars and is funded by federal grants awarded to New Orleans in January 2016. The project is projected to start construction in summer of 2018 and be complete the following year. Despite the huge impact this project will have for the Filmore neighborhood once complete, the City will have a long way to go. At a size of almost 350 square miles, it would take almost 1,600 projects of a similar scale to capture all the runoff. There is not enough land to capture it all, but the City is headed in the right direction.

 International examples of how a stormwater retention feature can double as a recreational feature (image courtesy of nola.gov)

International examples of how a stormwater retention feature can double as a recreational feature (image courtesy of nola.gov)