Solutions for Stormwater
No stranger to strong storms and tropical occurrences in the Gulf of Mexico, local builders in the New Orleans area continue to find creative ways to handle precipitation runoff.
Stormwater Management — essentially, the effort to reduce runoff from rain into streets and the sewer system — is an issue residential and commercial builders across the country must tackle with each new development, regardless of size.
Down here, though, the importance of doing so is magnified because of the region’s unique topography.
Essentially, New Orleans is a bowl — and bowls fill up fast.
“We’ve developed a pave, pipe and pump mentality,” said Jefferson Parish Councilwoman-At-Large Cynthia Lee-Sheng. “We’ve learned to not like water, and when it comes it causes a pandemonium — the number of calls we get to my office show that. Before it even touches the ground, we’re trying to pump it, and maintaining the infrastructure to do so is a cost burden on taxpayers.
“So the way we see water needs to change, and the way we handle it needs to change.”
For years now, Councilwoman Lee-Sheng has championed various Stormwater Management measures to lessen the stress and absolute dependence on the Parish pumping systems. Because of the region’s elevation and weather patterns, a pump system will always be necessary, but Lee-Sheng has fought to change zoning codes that hindered stormwater management and incentivize builders to use drainage-friendly designs.
“Every time you build a residential home or commercial building — if you put on a roof, or do additional paving, or build an access street — that takes away from the porous space for stormwater to be absorbed…it adds to the flooding problem,” said Diane Baum, a Baton Rouge-based environmental consultant for construction companies. “So as New Orleans is growing, Jefferson Parish is growing, these (construction developments) impede the capability of us to handle stormwater.
“And what local governments and agencies are asking for isn’t to stop building or impede progress. All they’re saying is, ‘You need to build smarter with stormwater in mind.’”
Generally, there are two types of Stormwater Management plans. The first, the Stormwater Pollution Prevention Plan, is implemented during the construction process when the land is unsettled. The goal of the plan is to prevent loose sediment from getting into the drainage system. The second, the Stormwater Management Plan, is more complex and often requires input from landscape architects and civil engineers. The plan is put into effect upon completion of the project and is designed to simultaneously lessen the rain runoff that leaves the property and to ensure the amount that does leave is relatively clean.
“Change can be a challenge when you’ve done things a certain way for years,” Baum said. “Basically, the way to create that change is through education and outreach, and then for cities and parishes to write the (stormwater) ordinances in a way that fully explains the goals they’re trying to achieve and give methods to fulfill those requirements and give them that guidance.”
An old school Stormwater Management method, which is still used today, is to build artificial “retention ponds” in the center of subdivisions or commercial complexes. These man-made bodies of water are designed to be both ornamental and a functional flood prevention tool. However, because Orleans and Jefferson Parish are already so densely populated, space to build retention ponds might not be available, leaving builders to use other methods.
Landscaping plans looking to maximize stormwater efficiency often include various swales — depressions that follow the contour of a slope to channel water from one place to another. At the base of these swales is vegetation planted at least a foot deep to hold and eventually dry up the water flow. In much the same mindset, many homes and office buildings are incorporating four-foot tall planters that function like rain barrels — a feature that beautifies the structure and absorbs drainage from the rooftop.
Beyond landscaping, the use of pervious concrete (which looks the same as standard concrete) for driveways and outdoor walkways has become increasingly popular in recent years. Unlike standard concrete, pervious concrete is porous — like a sponge — to allow water to drain into the underlying soils rather than run down into the street.
“That’s really the goal — to make stormwater management systems aesthetically pleasing,” Baum said, “to make it look like a really nice feature for the eye, not necessarily for a function.”