S&WB says turbine went down during heavy rains
NEW ORLEANS, La. (WVUE) - Heavy and relentless rainfall caused water to quickly pile up on New Orleans streets, resulting in flooding and the Sewerage and Water Board admits something that happened within its drainage system exacerbated the problem.
S&WB Executive Director Ghassan Korban says they had plenty of equipment online in anticipation of rain, but the amount that fell quickly was a surprise.
"First of all, this was an un-forecasted event. The National Weather Service issued a flash flood warning at 7:50 AM this morning. By that time, the rain was already coming heavy and already more than three inches had fallen in the Mid-City area,” Korban said.
He said the city’s drainage system could not keep up with that level of rainfall in a short period of time.
"When the storm was over more than four inches fell in the vicinity of Station 2, 3, and 17, that's roughly Mid-City, Gentilly and toward the lake. The bottom line is that this was more rain than our system could handle,” Korban said.
But rainfall amounts were not the only issue. Korban said there was a problem with a critical piece of power-generating equipment at their plant that powers pumps.
"Our pumps were operational but at 8:52 a.m., T4 which produces about 20 megawatts tripped offline. The loss of T4 slowed our ability to drain the city but the street flooding had already begun. According to the Real-Time Crime Camera Center cameras, we have significant evidence of street flooding before the incident of T4 occurring,” Korban added.
The technical problem made an already bad situation worse said Korban.
"T4 is our workhorse, it's the go-to turbine that carries baseload and it's the first piece of equipment, that power generating equipment that we use to power our pumps. What happened this morning is we believe that it may have been overloaded and that's why it tripped up. It has enough safeguards built in it to allow it to trip offline as to not basically get too damaged,” he said.
It took two hours to remedy the problem.
"What we needed to do is shift power from T4 to T1 and T3 and then the MDs and that takes some time and [what] we're not walking away from today is that occurrence did exacerbate the situation and likely slowed the draining of the city down, not causing the flooding,” Korban stated.
And as hurricane season progress the Sewerage and Water Board’s leader reminds everyone that the city's drainage system remains far from ideal.
"Somebody asked me during the week, over the weekend what is my biggest worry and I said T4 tripping or being damaged where it can't operate because that is our go-to power generation equipment,” said Korban.
And as the S&WB further investigates the T4 mishap Korban emphasizes the flooding would have likely occurred even without equipment failure on the city’s end.
"The amount of rain that came down all at once overrun the system and with T4 tripping or not tripping, I truly believe and we will quantify that, that the street flooding would occurred anyway,” he said.
He said they will explore ways to keep the turbine from being overloaded.
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