Pumping stations serving the two New Orleans neighborhoods hit hardest by Saturday's flood were operating at barely above half their full capacity, officials admitted Tuesday, directly contradicting assurances offered earlier by the Sewerage & Water Board and leading Mayor Mitch Landrieu to purge several top city officials.

The acknowledgement that critical portions of the mammoth system of pumps and canals intended to deal with heavy rainfall were down, pulled from S&WB officials during hours of testimony before the City Council on Tuesday afternoon, came after the agency had spent three days telling residents the pumps were operating to their fullest extent.

Cedric Grant, one of Mayor Mitch Landrieu’s highest-ranking deputies and the head of the Sewerage & Water Board, said he would retire at the end of hurricane season this fall, admitting that the public had lost confidence in his agency.

Public Works Director Mark Jernigan, who came under fire amid questions about whether his agency had done enough to clean the catch basins that feed the drainage system, submitted his resignation shortly after testifying to the City Council.

Landrieu said he would ask members of the S&WB this week to fire two other high-ranking officials, including the agency's general superintendent, Joe Becker.

Not seeing the video below? Click here.

Dani Galloway will become acting director of public works. Landrieu suggested that Robert Miller could take the helm at the S&WB after Grant's departure. 

During a grueling interrogation by City Council members at a public hearing, Becker was forced to withdraw repeated assertions that the city’s drainage pumps were operating at “full capacity” as the water rose Saturday. He acknowledged instead that the pumps were operating at the “capacity they had available to them,” drawing laughs and catcalls in a packed council chamber.

As it turned out, pumping stations in the hardest-hit areas of the city had lost more than a third of their capacity as a result of repairs and maintenance work. And issues traced back to the S&WB’s power plant on South Claiborne Avenue meant the pumps had to rely on Entergy for power, requiring power to be rationed in a way that cut further into the ability to move water through the complicated drainage system.

Overall, it took 14 hours to fully dry out the city from rainfall that ranged between 1 and 10 inches at various locations.

The drainage system is designed to handle 1 inch of rain in the first hour and a half-inch each hour after that. 

Becker, at times visibly pained by comments from angry residents behind him, insisted that the system would need to be hugely expanded to handle the amount of rain that fell Saturday without any flooding.

His comments did not satisfy council members, who clearly felt the answers they were getting were evasive if not downright false.

“If I didn’t follow up with you, I might have thought that less than a third (of capacity) was lost,” Councilman James Gray told Becker at one point. “The way my parents raised me, once they caught me not telling the truth, they didn’t believe anything I said.”

It was an unusually assertive display of anger from council members, and an embarrassing episode for Landrieu, who has sought during more than seven years in office to project an image of competence and sure-footedness in a crisis.

He has rarely criticized the work of his own staff, but he said during a news conference after Tuesday’s hearing that Becker had “danced around” the council’s questions.

“The obfuscation we saw today, it's insulting to the public,” Landrieu said. “Being open, honest and truthful is critically important.”

Although he has fired other officials, Landrieu's administration has generally been very stable, and this purge was unlike anything seen in the first seven years of his tenure. He leaves office in nine months.  

Beyond the resignations and firings, Landrieu said he has called for a full report from city officials on the response to the flooding as well as a third-party analysis of exactly what happened on Saturday and how that may have affected the amount and duration of the flooding.

Throughout his comments, Landrieu made clear that deception was the main issue in the terminations, repeatedly returning to the idea that “Mother Nature overwhelmed parts of our system” and that even at peak performance, the drainage system could not have prevented all the flooding.

That’s largely been the opinion of other experts as well, including meteorologists and outside agencies. More than 9 inches of rain was dumped on Mid-City in about four hours, nearly four times the amount the drainage system could handle in that time.

“In order to build a pumping system that would clear it out in three hours would cost a gargantuan amount of money. I can’t even imagine how much,” Landrieu said.

During the hearing, frustration built as council members interrogated Becker over which pumps were offline and how much pumping capacity was lost as a result. The picture that emerged was significantly different from what officials had portrayed over the weekend. Even so, it remained unclear how much flooding could have been prevented or mitigated by a fully operational system.

Over the weekend, Grant and other officials said publicly that the pumps were working at full capacity. Then on Monday, Becker told the media that while seven of the city’s 121 pumps were out of service for maintenance, that did not affect how much water the agency could move out of the city within a given time.

On Tuesday, Becker finally acknowledged that 20 pumps were inoperable, though he said the extra dozen were low-capacity pumps typically used to move runoff when the bigger pumps aren’t needed.

What proved explosive, however, was the revelation that some of the out-of-service pumps were in Mid-City and Lakeview and that they represented a big chunk of overall capacity in those hard-hit neighborhoods. In Lakeview, capacity at one point dropped to 52 percent because of the electrical issues.

In Mid-City, the pumps operated throughout the storm at about 63 percent of their total capacity. Other issues also caused one additional pump to go down for 20 minutes, though it was not clear exactly what impact that had on the overall amount of water pumped through that station.

The details came out only after extended questioning from council members.

Gray, in particular, had a change of heart over the course of the frustrating exchanges. He said that he initially was sympathetic to Grant, in particular after hearing shortly before the meeting began that he would retire.

Gray suggested he had thought some concerns expressed by many members of the public were overblown but those sentiments evaporated as he sought to pull information from Becker.

“I thought we were on a witch hunt, but I feel like we found witches,” Gray said.

Landrieu spokesman Tyronne Walker said the mayor’s office became aware of the extent of the problems late Monday, after Landrieu got back in town from a weekend trip to Aspen, Colorado. Walker said the mayor's office asked the S&WB for the logs from the pumps and realized “there were more pumps down than we had known.”

Sometime Monday evening, Grant also began discussing the possibility of his retirement as executive director of the S&WB and overall coordinator of all city infrastructure projects.

The pumping problems were among a litany of complaints raised by council members about the flood.

Some criticized the city’s Office of Homeland Security and Emergency Preparedness for waiting until the National Weather Service put out a flash flood warning to alert residents to the danger, even though 911 had received calls about flooding a half-hour earlier.

Others focused their ire on Jernigan and the Department of Public Works for failing to clean catch basins efficiently, which can keep water from getting into the drainage system in the first place. And more concerns were raised when it came out that the S&WB had not just misled the public but failed to notify the Emergency Preparedness office that not all pumps could be turned on.

Other concerns were raised about the lack of barricades to prevent cars from driving into flooded areas.

“Before we talk about spending an extra penny, we want to make sure that every dime we’ve spent so far is being used adequately,” Councilman Jason Williams said. “People are angry. They feel like they haven’t gotten answers. It doesn’t make anything better to hear that things are working when things are not working.”

The entire episode could have a major impact on the quasi-independent S&WB, though exactly what will happen to the agency is unclear.

Grant has been a pillar of the administration since the beginning of Landrieu’s first term in 2010, when he was appointed deputy mayor overseeing all capital and infrastructure projects.

Then, when the former head of the S&WB retired, Grant, with Landrieu’s backing, became the head of that agency while still keeping his infrastructure role, an attempt to better coordinate the work of two departments focused on construction. At the same time, changes were made to the membership of the civilian board that oversees the S&WB.

Tuesday’s revelations, and the overall lack of trust in the agency, could serve as a catalyst for a further overhaul.

When asked whether he would seek any changes to the S&WB’s governance or seek to align it even closer to City Hall, Landrieu said, “I think the board and the City Council are going to have to think through that. Everything should be on the table.”

Follow Jeff Adelson on Twitter, @jadelson.​