NEW ORLEANS — It shouldn’t be a surprise that Wednesday's sudden morning rainstorm caused major flooding in New Orleans while Tropical Storm Cristobal didn't, the head of the city’s troubled drainage system said.
“This city is one of the rainiest cities and it doesn't require a named storm to cause us flooding in this city,” said Sewerage & Water Board Executive Director Ghassan Korban, in an interview with WWL-TV on Thursday. “Five (to) six inches in two hours is an event that would overwhelm any system.”
But the old argument that New Orleans is simply a “city that floods” isn’t carrying water anymore with City Council members, who grilled Korban at a committee meeting Thursday. They were particularly concerned with the sudden loss of 100-year-old Turbine 4, the system’s workhorse generator for its older style of drainage pumps.
Korban was short on answers about why the turbine tripped offline at 8:52 a.m. Wednesday, just as the streets were beginning to flood in neighborhoods across the East Bank.
“We know that it tripped offline, either because it was overloaded or as a matter of fact maybe we could have removed some pumps out of service for that, or off (Turbine 4),” Korban said.
He promised the committee a report on why Turbine 4 tripped in the next day or two.
City Councilman Jay Banks said this should no longer be a surprise.
“This is going to continue to happen,” he said. “We keep acting like, 'Oh, we're surprised when it breaks.' Guess what? It's 100 years old, it's going to break again.”
Turbine 4 didn’t really break this time. It apparently tripped off automatically to protect against overexertion.
It did break, however, in 2012. It was offline for six years and cost more than $40 million to fix. Now, Korban says it could take only half that much -- an estimated $20 million -- to buy a brand new turbine to replace Turbine 5, a 70-year-old gas-fired generator that exploded in December and can't be salvaged.
Still, $20 million is money the Sewerage & Water Board doesn’t have right now. Extra tourism tax revenue that was expected to help with capital purchases has not materialized because of the pandemic. Korban said any seed money from the City Council would at least help him negotiate in good faith to find a good price for a modern turbine, one he calls “T7,” for Turbine 7.
The system has four turbines that are currently operational. Turbines 1 and 3 are smaller, steam-powered models. Turbine 2 no longer exists. Turbine 4 is also steam powered, but it is a huge 20-megawatt generator. Turbine 5 did offer 20 megawatts but now it’s kaput. Turbine 6 is a new gas-fired 15-megawatt unit installed in a separate building by the Corps of Engineers in 2016.
Before Turbine 5’s demise in December, the turbines provided 61 megawatts, with 12.5 megawatts of backup power from five backup generators purchased in 2017, called Electro-Motive Diesel generators or EMDs.
But as the rain poured down Wednesday, the city’s drainage system had lost 50 of those 73.5 megawatts of in-house power production.
One of the EMDs went down last month, leaving four to help out for the arrival of Tropical Storm Cristobal on Sunday. Another one went down at the end of Cristobal’s slow voyage across southeast Louisiana, Korban said.
The Sewerage & Water Board was ready to use the EMDs as a primary source of power, in case Turbine 4 went down. They created a loud, constant rumbling noise at the Carrollton Power Plant all day Sunday, but they were never really needed, as Cristobal only dumped about 2.5 inches on the city over the course of the whole day.
City Councilman Jared Brossett wanted to know why that same preparation wasn't done Wednesday with the three remaining EMDs, so they could have at least provided 7.5 megawatts as soon as Turbine 4 tripped off.
“Wouldn't it have been prudent to start the generators before Turbine 4 tripped after the 7:50 flash flood warning (from the National Weather Service), given that there was significant flooding throughout the city?” Brossett asked Korban.
“Yeah, again, in hindsight, I think I acquiesce to the fact that should have been considered and done,” Korban demurred.
Councilman Joe Giarrusso, the chairman of the Public Works Committee, wanted to know why Korban didn’t notify the public right away when Turbine 4 went down at 8:52 a.m.
“Why not let the public know immediately and warn what's going on so they can make own decisions, and by that I mean the nurse that's trying to get to work, whether or not she or he needs to turn around, the person who is in St. Claude, should they move their car?” Giarrusso said.
Korban said he and his team needed time to assess the situation after learning of Turbine 4’s tripping off. He said he informed the public at a news conference at 1 p.m. Wednesday. But Giarrusso pointed out that the local TV stations all cut into morning programming Wednesday morning to inform the public about the street flooding and encouraged Korban to figure out a way to get the message out more quickly about something like a major power loss.
Councilman Jason Williams asked about the possibility of bringing in an outside firm to run portions of the drainage system. Korban quickly shot that down.
“Our employees become extremely nervous about privatization,” he said.
Ramsey Green, Mayor LaToya Cantrell’s infrastructure czar, focused on some of the drainage system’s successes. He noted that water didn’t get into homes or cars in Gentilly Woods and Pontchatrain Park because of storm water retention projects there.
Famed actor Wendell Pierce, a Pontchartrain Park native who has criticized the city’s Pontilly Neighborhood Stormwater Network green infrastructure project, filmed the gardens full of water and posted his approval on Twitter.
“The Pontilly Stormwater Project, of retention ponds & management of the rainwater flow, worked. I had my doubts. The water is gone,” Pierce said.