There are two bold new additions rising from the landscape in Uptown New Orleans.
The Sewerage & Water Board is constructing two 200-foot-tall water towers at the Carrollton Water Plant as part of the $80 million Water Hammer Hazard Mitigation Program. Funded by the Federal Emergency Management Agency’s (FEMA) Hazard Mitigation Grant Program (HMGP), the project is designed to prevent major damage to the city’s water piping infrastructure from water hammer effects.
A water hammer effect occurs when water in the system is suddenly forced to stop moving due to a loss of power or a major water main break and the valve closure slams shut, reverberating through the system. The momentum of the water stopping abruptly creates a pressure wave that travels through the water in the pipe system, which subjects everything in that closed system to significant forces. Pressure spikes can do serious damage to a system within a very short time period.
The project will help stabilize water pressure and mitigate the negative effect on the system including preventing damage to water lines and reducing the possibility of broken pipes and future boil water orders.
“It will allow us roughly 30-40 minutes of continuous water pressure in the event of a power failure,” said Chris Bergeron, P.E., Water Hammer Program Manager. “There’s no operation involved – no turning it on. It ties into the main water pressure of the system so it’s always just working.”
Each of the towers is constructed using a 54” pipe inside of the tower’s pedestal that carries the water to and from the steel top where the water is stored.
“Imagine if we pumped water into the tank with a pipe attached to the water system, but we put a valve in there,” explains Bergeron. “So basically we have two million gallons of water in the air being held up by a valve. Once we open the valve, it will all flow out into the system. In reality, instead of a valve, it’s the pressure in the system holding that water up. It’s a direct relationship of the pressure in the system and elevation of the water in the tank, so 68 psi in the system means the water in the tank is 157 feet up. As that pressure drops, so does the water in the tank.”
The project, which began with the design phase in 2011, is scheduled to be completed in 2023. Construction of the project is divided into three phases. Phase 1 is the construction of the two water towers – the Claiborne Tower and the Panola Tower – and Phase 2 includes improvements to the Claiborne Pumping Station and the four water distribution pumps and motors. Phase 3 includes improvements to the Panola Pump Room and the steam pump rooms and replacing metering, valves and auxiliaries.
The Claiborne Tower is slated for completion in November 2018, and the Panola Water Tower is scheduled to be complete in April 2019.