“Living with water” has become a catchphrase in New Orleans, where crumbling infrastructure and increasingly frequent intense weather have made flooded streets and buildings all too common. Another culprit is the pavement that, here as in other populated areas, replaces rainwater-absorbing green space.
The City Council recently took a step toward tackling that particular piece of the drainage puzzle when it voted to require all new commercial parking surfaces to be water permeable. The underlying idea is that, with modern materials now available, parking lots don’t have to be part of the problem. They can, in fact, contribute to a multi-faceted solution.
“Simply put … water cannot simply be absorbed through traditional pavement and concrete,” said Councilman Jason Williams, co-sponsor of the ordinance that passed unanimously. “Permeable solutions ... allow water to be absorbed into the ground, reduce runoff volumes, mitigate flooding and reduce subsidence.”
Several variations on the theme are available to developers. One is pervious concrete or asphalt. Another is connected plastic paving filled in with gravel. The costs vary, but are generally not much more expensive than for traditional materials, and are in some cases slightly cheaper.
The ordinance is part of a broader effort to reduce the amount of water that the city’s aging drainage system has to handle when it pours.
The city's code was recently amended to require certain developments to keep the first 1.25 inches of rainfall from entering the drainage system during storms. And the city itself has invested more than $120 million in "green" infrastructure projects, including porous pavement on public streets. Other strategies included in the six-year-old Greater New Orleans Urban Water Plan include building rain gardens and other installations that can absorb or hold water.
"We cannot pump our way out of this problem, and we need to hold water before it goes into the drainage system," Deputy Chief Administrative Officer for Infrastructure Ramsey Green said recently.
These initiatives alone won’t solve a problem that has been decades in the making. Indeed, one of Mayor LaToya Cantrell and the council’s most urgent challenges is cobbling together enough money to pay for massive drainage upgrades the city and Sewerage & Water Board hope to implement.
But this much is obvious: The less water that flows into the system, the less the clogged, leaky pipes will have to transport, and the less the pumps will have to remove.
So the more ways the city can devise to keep water out of the system in the first place, the better.