Green Roof Atop the S&WB Building Helps Handle Stormwater Runoff Through the Beauty of Flowers
Sourced from the New Orleans Advocate
From the sidewalk, the New Orleans Sewerage and Water Board’s administration building at 625 St. Joseph St. seems inconspicuous. But from high above, it looks like a Central Business District urban oasis, brimming with Louisiana irises, calla lilies, jasmine and creeping juniper.
The beautiful blooms serve a purpose that extends beyond aesthetics, however. They are part of the building's green roof — a type of green infrastructure that regulates rainwater, acts as insulation and improves both air and water quality. The green roof spans 10,592 square feet and can manage more than 15,000 gallons of rain, per storm.
“The roots of those plants helps soak up water that would enter the storm-water system,” said Grace Vogel, a senior city planner for S&WB and a licensed landscape architect. “The roots grab as much water as they can before the water slowly percolates into the drains on the roof and goes into the gather system.”
A blue roof, which also sits atop the building, temporarily holds stormwater to slow its runoff into the drainage system. The roof's smart drain closes when it senses a specified amount of rainwater is being detained; then hundreds of gallons can be released into the drainage system slowly, rather than in a flood.