LAKEVIEW, La. — The severely weakened New Orleans drainage system performed well this week in the face of 6 to 8 inches of rain over 48 hours, but an old problem crept up in one small section of town where street flooding has been a regular occurrence.
The single pump used to drain the West End section of Lakeview started spinning backwards Wednesday morning and sucked water in from Lake Pontchartrain, rather than sending the water from the streets out into the lake.
The resulting bumper-high water was not an unusual sight at 35th and Center streets in the West End neighborhood. But the fact that the water appeared to rise after the rain stopped was perplexing. Weary residents wondered if Wednesday morning’s flood was a result of clogged catch basins or malfunctioning drainage pumps.
“What happens is, after it rains, is really when it's dangerous,” said Tim Zissis, who was out trying to make sure the water went down Wednesday morning. “You really don't know what it's going to do until it stops, see what the pumps are actually doing and then it starts filling up like a water bowl.”
“Probably the pumps were not draining, just right here,” added Calli Terrell, another neighbor. “The street floods all the time.”
What the neighbors didn’t know was how spectacularly the single pump responsible for draining their area failed them.
“D” Pump at Pump Station 12 on Pontchartrain Boulevard tripped offline at 7 a.m. Wednesday because the electricity coming from the Sewerage & Water Board’s Carrollton Power Plant was about to overload the machinery, an agency spokesperson told WWL-TV.
But when it automatically switched off, the motor started spinning in reverse, the agency said. That meant water from Lake Pontchartrain was actually being sucked back into the drainage system, explaining why water levels initially rose in the streets after it stopped raining.
A hydraulic valve that can be opened to break a vacuum in the pump didn’t open, requiring the pump operator to open a manual backup valve and stop the reverse suction. Engineer Matt McBride, a frequent Sewerage & Water Board critic who documented other instances of pumps spinning in reverse during citywide flooding in August 2017, said the Sewerage and Water Board has replaced several hydraulic valves with pneumatic ones, but not yet at Pump Station 12.
That station is also the only one in the system that has only one electricity feeder line, according to Sewerage and Water Board records, meaning there is no redundancy built-in.
Some of the larger drainage pumps also have brakes to stop a spinning motor, but not “D” Pump at Station 12. That means the pump operator had to wait for the motor to stop spinning on its own Wednesday, a process that can take as long as 30 minutes.
The agency confirmed it took 47 minutes before the operator was able to prime the pump to restart, and a full hour before it could start pumping in the right direction again, at 9 a.m.
The Sewerage and Water Board did not make any public announcements about “D” Pump tripping off until late Wednesday afternoon when WWL-TV asked the agency about Terrell’s contention that the pump didn’t appear to be working. That’s when it acknowledged it was out for an hour.
Pump Station 12 failed to operate during the 2017 flooding because it was unmanned. The Sewerage and Water Board initially claimed it had been pumping the whole time. With that spotty history in mind, City Councilman Joe Giarrusso said the Sewerage and Water Board needs to be more forthright about failures there and clearly communicate about its plans to address the problems moving forward.