Twin 200-foot towers to be built at city’s water plant _lowres

Artist rendering provided by Sewage and Water Board pf New Orleans --

A pair of water towers that would dwarf Uptown New Orleans’ mostly low-rise buildings could soon rise above the Sewerage & Water Board’s campus on South Claiborne Avenue as part of a project aimed at preventing swings in water pressure that can cause boil-water advisories and damage to the system’s pipes.

The twin 200-foot-tall towers, each capable of holding up to 2 million gallons of water, would work with two new ground-level tanks and allow for pressure to be maintained for up to 45 minutes even if the water system loses power.

“What these tanks will allow us to do is continuously provide water to all of you and give us sufficient time that when we lose power from our commercial vendor, there will be time to turn on our own power,” S&WB Deputy General Superintendent Madeline Goddard told neighbors of the water plant at a community meeting on the project Thursday night.

The tanks would be slightly shorter than the chimney that’s already on the S&WB campus, but they still would be among the tallest structures in New Orleans outside of the Central Business District.

The tanks would serve two purposes. They would kick in if the water purification and pumping plant loses power from both Entergy and its own internal generators, thereby keeping it from pumping water through the pipes. There have been two outages in the last several years that took the pumps offline, and while they lasted only a few minutes, they caused water pressure to drop enough to require the water board to issue boil-water advisories to most of the city.

Keeping the pipes pressurized also would prevent damage caused to the pipes when the pumps are turned back on.

The pumps used by the S&WB have only two settings: They’re either off or running at full blast. But a sudden increase in water pressure can cause shockwaves in the pipes that can cause significant damage, leading to leaks or water main breaks, Goddard said.

The project, which is being funded by the Federal Emergency Management Agency, will include repairs and upgrades that will allow the S&WB to vary the speed of the motors that power the pumps to ease the system back to full power, further protecting the pipelines, Goddard said.

The ground-level tanks, each capable of holding about 2,000 gallons of water, would be located on Chef Menteur Highway in New Orleans East and on Stroelitz Street in Uptown, housed in buildings designed to blend in with the houses around them, Goddard said. Those tanks are needed to provide additional pressure in those areas.

Overall, FEMA is expected pay about $48 million for the project — money that it is providing to protect the pipelines it already has paid to replace and upgrade, Goddard said. That comes in addition to roughly $200 million the agency is spending on other upgrades.

Construction on the towers is expected to start after crews wrap up work on the Southeast Louisiana Urban Flood Control drainage project on Claiborne Avenue next fall.

The work will require keeping one lane of Claiborne closed to traffic, though most of the actual construction will occur on the S&WB campus near the Jefferson Parish line.

Because the work will be set back from nearby residential areas, the project, expected to wrap up in 2018, should cause less of a disturbance to neighbors than the current construction in the area, General Superintendent Joseph Becker said.

The prospect of tall water towers near a residential area raised concern from at least one nearby resident, however. Robert Welch, who lives next to the water plant, said he worries a storm could knock over the structures and cause damage and flooding in the area.

“How safe are these tanks for the residents of this area? How reliable are they going to be?” Welch asked.

“If a mega-storm like Katrina comes again, will these things be safe like the old tanks?”

The towers would be designed to withstand 150 mph winds, he was told.

“If we had any concerns about that whatsoever, we certainly wouldn’t want it where we pump the water to everyone,” Becker said.

Follow Jeff Adelson on Twitter, @jadelson.