Could having homeowners install water retention ponds and cisterns on their property be part of the solution to New Orleans’ chronic flooding problem? There’s some evidence to suggest that this DIY approach to flood mitigation could make a big impact in the Cresent City.
New Orleans Deputy CAO Ramsey Green told WWL if more homeowners were to get on board with holding water on their property, it would make a big difference in the flood fight, particularly during severe rain events.
“If you hold 2,000 gallons on 100,000 properties, that’s 200,000,000 gallons of water, that puts a big dent into how much flooding our city holds,” said Green. “2,000 gallons is not a huge amount.”
New Orleans, as most residents are well aware, is built on top of a swamp that’s slowly been covered in concrete. Green indicated the residential retention plan is about working with nature, and not against it.
“It’s really going back to the ecological origin of New Orleans,” said Green.
Residential water retention can take a lot of forms, from a simple cistern to more complex systems that feed water-hungry rain gardens.
“I built about five feet down in my own backyard these big tanks filled with water, and I have grass over it, my kids play soccer right over where I hold a lot of water, and that connects to a rain garden on the side of my home,” said Green. “It really makes it a more beautiful place, I mean we attract little butterflies who were never there before, and it is beautiful.”
Louisianans have been taught from birth not to let standing water stay on their property because of mosquitos. That has some concerned about the public health impact of residential water retention ponds, but Green argues if they are built right, there’s really no risk.
“Those fill up with water, the water sits, and then it recedes within 72 hours,” said Green who added that mosquitos need 10-14 days to reproduce in standing water.
Green said the city is committed to improving the core drainage system but is also considering using bonds to fund an incentive program that would reimburse homeowners for holding water on their property. He said there’s already been a somewhat similar, if smaller scale, version of this program in Gentilly that was a great success.
“We took some federal money and in the greater Gentilly area put substantial resources into people’s homes because those properties are a little bigger than in Uptown, or close to the historic core of the city, and held tremendous amounts of water in people’s back yards and that was paid for by the city,” said Green.
Green noted the city is focusing on water retention projects on public lands, including the nine million gallon system at Joe Bartholomew Golf Course.
So, what kind of price tag can a homeowner expect if they’d like to hold some water at their home?
“For a cistern, we’re talking $100 to a couple of hundred dollars,” said Green. “For something bigger where you are doing a subsurface pond, french drain, a big rain garden? $10,000.”
