New Orleans City Park has 137 acres of water bodies with 22 linear miles of lagoon edge. Within the Park, there are two separate circulation systems, divided by I-610 and the railroad. Brackish water from Lake Pontchartrain flows into Bayou St. John and enters the Park’s lagoon system at three locations, one north of I-610 and two to the south. Water moves through the lagoon system and is discharged through several weirs back into Lake Pontchartrain via the Sewerage and Water Board Pump Station No. 7 at Marconi Drive and Florida Blvd. The operable discharge weir on the south side of I-610, installed in 2017 as a part of the South Golf Course construction, allows us to lower the lagoon levels on that end of the park in advance of anticipated major rain events, enabling us to store additional water to postpone discharge into the City’s already overburdened pump station. This helps to mitigate flooding in adjacent neighborhoods.
Stormwater Best Management Practices (BMP’s)
City Park has implemented several Stormwater Best Management Practices (BMP’s) in new construction projects that allow the Park to store additional water and mitigate flooding. As Park amenities are developed, there is greater opportunity for stormwater storage. We will continue to implement green infrastructure projects in lieu of traditional grey infrastructure.
Permeable Parking Lots: We have installed two permeable asphalt parking lots in the Park – one at the Administration Building and one at the Pelican Greenhouse. These parking lots filter and store water before overflow water is discharged to the City system. Delaying this water from entering the system allows stormwater from other adjacent areas to take priority in the pump stations.
Bioswale/Wetlands: City Park has created four major stormwater storage areas.
• Festival Grounds Constructed Wetland – Constructed in 2011, this bioswale is 31,193 square feet and has an 187,000 gallon capacity, which allows it to detain one-third of the stormwater that falls on the 50-acre venue. The bioswale was designed by Dana Brown and Associates, and consists of several zones with varying elevations and water depths, to support a variety of native plants and aquatic critters.
• Tricentennial Parking Lot Bioswale – Constructed in 2012, 7,800 square feet.
• Overflow Parking Lot on Dreyfus Dr. – Constructed in 2016, 1,628 square feet.
• South Golf Course Maintenance Building Bioswale – Constructed in 2017, 4,200 square feet.
Lagoon Improvement Study
A study by local architects Waggonner and Ball, and Deltares, a Dutch applied research institute specializing in water management, recommends improvements to the lagoon system which would increase the capacity of the lagoons by deepening and reconfiguring the water bodies and adding more operable control structures at the discharge points. This would allow the Park to store more water during severe weather events. By redirecting water from adjacent neighborhoods away from the City’s drainage system and into the Park, this could further mitigate the overloading of the City’s pumping system and allow areas of more frequent flooding to drain first. This proposal is currently being considered as a part of the Hazard Mitigation Grant program.