NEW ORLEANS -- Mayor Mitch Landrieu on Tuesday effectively fired the heads of the Sewerage & Water Board and Department of Public Works during a press conference carried on live TV as anger about recent flooding continued to grow following revelations that some pumping stations were only working at half-capacity, despite claims to the contrary.

"This may not be the end of it," Landrieu said of the shakeup. "I don't know."

Hours earlier, Sewerage & Water Board Executive Director Cedric Grant announced he would retire after hurricane season. That news came minutes before a special City Council meeting about the flood response began and stunned S&WB employees who learned it from media reports.

Landrieu, who as mayor serves as president of the S&WB, said during his 5 p.m. press conference that he would call a special board meeting for Thursday, at which time he would recommend the termination of General Superintendent Joe Becker and Communications Director Lisa Martin.

Meanwhile, he announced he would replace Col. Mark Jernigan as head of the Department of Public Works after accepting his resignation.

Jernigan's retirement will be effective Aug. 18. He will be replaced on an interim basis by Dani Galloway, Grant's chief of staff.

Last week, Jernigan got an earful from a City Council committee and residents angry about clogged and broken catch basins that have been slow to be cleared or fixed. Clogged drains that were too slow to drain were blamed for exacerbating the flooding problem.

The purge stemmed from post-flood statements that officials made that claimed the city’s drainage system was working to capacity before slowly admitting that eight pumps were out of service for routine maintenance. Landrieu said the S&WB has no credibility with the public.

“It's inaccurate to suggest the system was operating at its maximum abilities,” Landrieu said. “This was not true and this is unacceptable.”

Landrieu was in Aspen, Colorado, for a conference when the flooding happened. He told WWL-TV political analyst Clancy DuBos he did not return sooner since he was getting the same bad information as the public.

“You could see and hear the frustration in his body language and his voice,” DuBos said. “He was very upset because he feels his credibility is at stake as is the credibility of the Sewerage & Water Board.”

Landrieu hired Grant and Jernigan for their posts.

“He’s letting go people he put it place. That’s holding people accountable,” DuBos said.