Big Box Stores, Stormwater And Zoning Ordinances, Oh My

Dec 1, 2014

The parking lot of the new Walmart in Gentilly.
Credit Laine Kaplan-Levenson / WWNO

In January the New Orleans City Council will resume hearings on a new Comprehensive Zoning Ordinance. It’s been 40 years since the city was this close to revamping regulations on how things get built.

As part of the CZO, a group of city officials, engineers and landscape architects are pushing for a greener design for New Orleans. One that will help the city better manage its localized flooding.

Matt Hollon, environmental program manager with the City of Austin, Texas’s Department of Watershed Management, recently showed a group of visiting New Orleans political leaders how porous pavement works by emptying a bottle of water onto the surface that absorbs liquids. But the scene was not happening in a lab. It’s a Walmart parking lot.

“They’ve got curb cuts in their medians, in their parking lot that allows stormwater to infiltrate," he said. "They’ve got a foot or two of gravel below their water quality and detention ponds that allows that to fill with stormwater and infiltrate.”

These green infrastructure features weren't all required; some were implemented by Walmart in addition to what was asked by the City of Austin. One city worker refers to the measures, which help absorb runoff from flash floods, and clean rainwater before it heads to a nearby creek, as, "kinda cool."

Water being poured on porous pavement at an Austin Walmart parking lot
Credit Jesse Hardman / WWNO

Kinda cool, and expected for big developers in a progressive city like Austin. But "kinda cool" aren’t the words New Orleans landscape architect Elizabeth Mossep would use to describe a Walmart parking lot here.

The store she's thinking about, recently built off of Gentilly Boulevard, is a sea of concrete with a few small shrubs and trees.

"What we're seeing is absolutely, stock-standard, lowest common denominator parking lot," she says. "We've got acres of concrete, we've got concrete curbs, and then we've got the minimum landscape requirements that are required under the building code."

In this Walmart parking lot, rainwater gets redirected into the local drainage system as quickly as possible. That’s true for the new Costco and medical buildings being built along Tulane Avenue as well too. Why are developers still paving over a city known for its floods?

"There has been no storm water regulations in this city. There's been no landscape regulations in this city," says Dale Thayer, a senior environmental planner for the City of New Orleans. He’s been part of the team drafting a new comprehensive zoning ordinance, or CZO, something the city hasn’t done in 40 years.

He says continuing to allow developers to pave over everything isn’t sustainable. "Once you back up the storm drains, then the integrity of that subsurface infrastructure gets fractured over time." That’s when you get concrete cracking and sinking.

Under the new CZO, developers will have to design buildings that absorb stormwater on site, and consult experts about water management strategies. Local landscape architect Dana Brown says that means actually asking businesses that want to build here to go the extra mile.

"We don’t value ourselves enough," she says. "We think we should be out there begging for someone to come here and we should be walking around a bit snootier. We should say 'You wanna come here? Okay, this is what you need to do — and if you don't want to do that, then you can’t come.'"

A stormwater retention site behind a Walmart in Austin, Texas.
Credit Jesse Hardman / WWNO

New Orleans City Councilmember Susan Guidry says she’s glad Costco wanted build in her neighborhood, but regrets the missed opportunity with the parking lot. "Nobody made 'em do anything with regard to stormwater management — this is when I told myself 'never again.'"

The city was worried Costco would build outside Orleans Parish if the company was asked to do anything special. But landscape architect Elizabeth Mossep says companies can save money through green design. She says a green retrofit on a parking lot in Baton Rouge saved a client millions.

Back at the Walmart parking lot, Mossep is imagining what might have been if she’d been consulted on the building plan. "We would see more tree canopy, and we'd probably see a series of detention basins or rain gardens around the periphery of the site."

Pouring a bottle of water on the concrete parking lot brings Mossep back to reality. "The water is just puddling there on the concrete. It’s not getting used, it’s just making the concrete wet."

Mossep is hoping, if the new comprehensive zoning ordinance gets passed, the next big parking lot built in New Orleans will put that water to use.

Support for WWNO's Coastal Desk comes from the Walton Family Foundation, the Greater New Orleans Foundation, and the Kabacoff Family Foundation.