Strategy change touted for water management

When the water begins to rise in the city’s streets during bad weather, the Sewerage & Water Board’s two dozen massive pumps can suck out the water at a rate equal to the flow of the Ohio River.

That rush to drain the city, according to one architect and the S&WB’s general superintendent, shouldn’t always be the goal.

David Waggonner’s agency, Waggonner & Ball Architects has been asked to develop a water-management strategy for St. Bernard Parish and the east banks of Orleans and Jefferson parishes. He said the Dutch, who have embraced water and learned to harness it, should inspire future plans here.

That idea gained popularity in the aftermath of Hurricane Katrina, when officials studied the Netherland’s water-management system.

“We don’t actually have to drain every drop of water that falls,” Waggonner said.

The desire to quickly remove all standing water can have detrimental effects, such as drying out the ground and assisting subsidence.

Waggonner said people should adopt a new model: store water and drain it only when necessary. That has worked well for eastern New Orleans, according to S&WB General Superintendent Joseph Becker.

The 19,000 acres that make up that part of the city have a pumping capacity of 6,000 cubic square feet a second. That’s compared to Algiers, which has 11,300 acres and can pump at 6,300 csf.

The reason the east needs less drainage capacity is that many neighborhoods were built around man-made lakes that hold rainwater runoff, reducing the need for larger pumping capacity.

Becker noted that there isn’t a large flooding problem in eastern New Orleans because of this system. Convincing other parts of the city, particularly residents in the older neighborhoods, to embrace a new way of dealing with water won’t be easy.

“Nobody has ever told me ‘I used to have a ditch in front of my house. I want it back,’” Becker said.

Waggonner agreed that a paradigm shift of that magnitude won’t be easy for many New Orleanians, especially after Katrina. Still, he said, it must happen for the city to survive.

The massive concrete floodwalls that block outfall canals, for example, are not the right way to handle the situation. Bayou St. John, he noted, is a good example of an urban waterway that is functional without being a flood risk.

Action such as cultivating accessible canals can have other effects, Waggonner said, such as increasing property values and attracting new residents to the city.

“We have to quit acting like the way we did it in the past is the only way,” he said. “If we don’t learn to manage water, we don’t have a home,” Waggonner said.