New Orleans is waking up to the need for a very different approach to water management. We have begun to understand that we need to “live with water” rather than persist in the delusion that we can somehow wall ourselves off from it.

But how do we pay for the new approaches? It’s more than a matter of building ever-higher levees and bigger pumps and drainage canals.

The flooding from rainfall events, such as the one on Aug. 5, and the subsequent fallout at the Sewerage and Water Board come with costs. Residents suffered damage to cars and homes; some lost jobs. As a community, we need government institutions capable of providing needed services, and we must look out for our neighbors during these flood events.

We also need to address this hard truth: New Orleans simply cannot pump enough water to eliminate the flooding that occurs when we have major rainfall events, like the nine inches that deluged some places on Aug. 5. Nor will we ever be able to do so.

But if we can’t pump it away, what do we do to stay safe?

As New Orleanians, we must have a fully functional drainage system and Sewerage and Water Board. Additionally, we need more “green infrastructure” to reduce the demands on the drainage system during our big thunderstorms. Green infrastructure uses nature-inspired solutions to manage storm water. Think of the parks, ditches, and gardens near your house — these places help slow, store, and drain water. They reduce the amount of water we need to pump and help keep us safe.

Green infrastructure is not a replacement for the pipes, canals, and pumps that comprise conventional “gray” infrastructure. But it can provide us with an extra layer of protection. Often, green infrastructure is more cost-effective than adding more gray infrastructure.

A 2007 report by the federal Environmental Protection Agency found that, on average, green infrastructure was 19 percent less expensive than conventional approaches. When completed in 2020, the Mirabeau Water Garden in Gentilly will be able to absorb 7.8 million gallons of storm water from the surrounding neighborhood during a 10-year storm. With a stable local funding source for municipal green infrastructure, equally beneficial projects could be built in other neighborhoods across the city.

The sooner we define and adopt a thoughtful, equitable flood-reduction fee, the better.

Combined, these methods can significantly reduce the amount of water that goes into the drainage system. They have the added benefit of keeping the soils upon which our city is built from drying up. Think of our soil as a sponge; the wetter it stays, the less it shrinks. In turn, this reduces the subsidence that cracks building slabs, sidewalks and streets. Investment in green infrastructure is a pothole-reduction strategy as well as a flood-reduction strategy.

Green infrastructure also reduces the amount of pollutants that go into our drainage system and surrounding waterways, such as Lake Pontchartrain. It also reduces the urban “heat island” effect and improves air quality.

Unfortunately, neither our gray infrastructure of pipes, canals and pumps nor our green infrastructure are anywhere close to where we need them to be to make New Orleans a safe, livable city far into the future. Let’s cut to the chase: We need more money to build and maintain this infrastructure.

What we do not need is another property tax to raise these funds. For various reasons, property taxes are increasingly inequitable in our city, with large institutions paying nothing while individual, moderate-income residents struggle mightily to pay their property tax bills along with everything else.

A fairer approach would be a “flood-reduction fee.” Every property owner — no exceptions — would pay such a fee based on the amount of water that runs off the owner’s property when it rains. The fee could ultimately make New Orleans much safer while reducing street and building repair costs.

Under a thoughtfully structured fee system, the city would set an appropriate baseline amount of runoff per square foot of land. Runoff above that amount would be subject to the fee. Property owners who took steps to reduce runoff — by installing rain gardens or reducing excessive paving, for example — could see their fee reduced or even eliminated.

Very simply, if you are using the drainage system extensively, you pay a fee; if you are using the drainage system less heavily, you pay little or no fee.

While the bulk of the funds generated from this fee should be dedicated to a combination of improving and maintaining the drainage system and building more green infrastructure on public lands, a portion should be set aside to assist low-income homeowners and small nonprofits (such as neighborhood churches) to take steps to reduce their rainfall runoff. Other incentives should also be considered, such as low- or no-interest loans to businesses to retrofit their properties in ways that reduce runoff.

Additionally, we need to determine who collects the money, and how to ensure that all expenditures of the funds are completely transparent. In the bigger picture, we need to discuss which current city entity should be responsible for the drainage system, or whether we need a new entity.

The technology exists to measure property runoff very accurately. It is used by city governments all over the United States to implement similar flood-reduction fees. In fact, approximately 1,300 jurisdictions around the U.S. have these fees, with the average residential property owner paying $5.12 per month. A New Orleans version can be developed using the very best ideas from comparable cities.

We are not talking about doing anything new or earth-shattering — or expensive, for that matter. We are simply suggesting that we use a proven method that could be easily implemented to solve major problems in New Orleans.

The sooner we define and adopt a thoughtful, equitable flood-reduction fee, the better. This will require the mayor we elect on Nov. 18 to show bold leadership. Both candidates have pledged to make the city a leader in water management, and that requires a fairer, smarter approach to financing flood reduction.

The rain is going to keep falling. The only real question is this: Are we as a city going to get smarter and better about what to do with the rain after it hits the ground?

Miriam Belblidia, CFM, MPA, is co-founder and chief executive officer of Water Works, L3C, and president of the Water Collaborative of Greater New Orleans. Colleen Butler, PhD, CFM, owns Lotus Eco Systems, LLC. She chairs the Research and Policy Working Group for the Water Collaborative of Greater New Orleans.

Views expressed in the Opinion section are not necessarily those of The Lens or its staff. To propose an idea for a column, contact Lens founder Karen Gadbois.