New Orleans officials still are not sure how quickly water can be pumped out of the city during a severe storm, but they hope to have a better idea of the impaired drainage system’s capacity before any rain from Hurricane Harvey hits the area.

The storm, whose outer bands could dump torrential rain on the area starting late this weekend, is expected to make landfall in Texas by Saturday.

Even at that distance, it is likely to drop enough rain on New Orleans that problems could arise in the wake of revelations of serious problems with the Sewerage & Water Board drainage system that pumps out the city.

With even more serious rain expected elsewhere in the state, Gov. John Bel Edwards has declared a state of emergency.

Local officials said Thursday they’re waiting for more information about the status of the drainage system, which could come as early as Friday, and a better sense of what Harvey’s eventual path might be.

“We’re in a more vulnerable space than we should be in,” Mayor Mitch Landrieu said, though he and other officials insisted that the system, while below its ideal state, is in better shape than it was during the Aug. 5 flood.

Moves have been made to shore up the system's capacity, including emergency repairs to the pumps and the addition of back-up generators to take over in case of problems in getting power to the pump stations from the S&WB’s power plant, where only two of the five turbines are working, or from Entergy.

A total of 106 of the city's 120 drainage pumps are now online, after three that were down during the flooding earlier this month were repaired.

State and federal officials have been working with the Landrieu administration to pre-position assets that could be needed in case of flooding, including high-water vehicles, boats and portable pumps.

"It is organizing and gaining strength over time," Edwards said of Harvey after a Thursday afternoon briefing with other officials and updates from the National Weather Service. "The nature of this storm has changed very much over the last number of hours. It's getting more and more serious as time goes by."

Harvey is expected to strengthen to a Category 3 hurricane with winds of up to 125 mph before making landfall on the south Texas coast. Forecast models are unclear on what it will do after that, but predictions suggest it could move back into the Gulf and present a more direct threat to Louisiana.

For now, forecasters predict between 5 inches and 10 inches of rain over the New Orleans region between Saturday and Wednesday, with some areas seeing significantly higher amounts, said Mike Efferson, a meteorologist with the National Weather Service station in Slidell.

However, Efferson warned there is a lot of uncertainty about those estimates, in part because the currents steering the storm are relatively weak, making its path and strength difficult to predict.

Locally, the rain will start Saturday, though that will likely be a relatively typical rain for the area, Efferson said.

More serious rainfall is expected to start the next day, with 2 to 4 inches falling on the region Sunday through Monday, Efferson said. The New Orleans area could see another 3 to 4 inches on Tuesday and Wednesday, he said.

During the Aug. 5 flood, about 9.4 inches of rain fell on Mid-City, one of the hardest-hit areas, over about four hours. Other areas of the city saw more than 5 inches of rain over the same time period.

Officials do not appear to think that an evacuation of the city will be necessary, though state, local and federal officials have had discussions of what could trigger such a call.

“We have an evacuation plan for a Category 3 hurricane,” Landrieu said, referring to plans for a major storm that hits near the New Orleans area. “The question is whether there’s a different trigger (for a lesser storm). The answer is, ‘Not yet.’ "

Edwards also said it was too early to call for an evacuation.

"We are making sure that we have current plans in place in New Orleans and identifying those areas that are particularly vulnerable," he said. "The planning has been refined, but I don't want anybody to think that we or the city of New Orleans at this time is close to pulling the trigger on evacuation."

The situation is precarious because officials no longer have confidence about how quickly water can be drained out of the city. The S&WB has traditionally said the drainage system can handle 1 inch of water in the first hour of a storm and a half-inch every hour after that, but officials now say they cannot say for sure whether that rate is, or ever was, accurate.

In another development Thursday, the New Orleans City Council approved two appointments of Sewerage & Water Board members, a small reprieve for a board hit by two resignations in the aftermath of the flooding earlier this month.

The approved appointments are of Joseph Peychaud, a current member, and Stacy Horn-Koch, a new appointee. They bring the board to seven members, which is enough to get business done even if one member misses a meeting.

While Horn-Koch was not present for the council's vote, Peychaud gave an impassioned defense of his public service. He denied knowing about major issues hampering the city’s drainage system before the Aug. 5 deluge.

“The analogy for me is this: If you are not aware, then you can’t act,” Peychaud said. “And I can only respond to you that I and other members did not have the information that was presented to us (after the flooding) and was presented to you.”

He spoke after Councilwoman Susan Guidry asked him about his and other board members’ apparent ignorance about the system’s problems.

Peychaud denied knowing about the broken turbines in particular, even though he sits on the board’s Finance Committee, which was told in March that four of the five turbines were down and the system had to rely on a backup generator. That committee then agreed to approve an emergency contract to fix the problem.

Peychaud, who is president of St. Katharine Drexel Preparatory School, was present at the March meeting. 

While LaToya Cantrell and others on the council have called for requiring S&WB members to have career experience relevant to the agency they oversee, Cantrell said Thursday she was satisfied with Horn-Koch's and Peychaud’s qualifications for the time being, as the board needs to have enough members to handle the agency's business.

The council on Thursday also agreed to waive fees for residents seeking city building permits to repair structures damaged in the Aug. 5 flood.

Staff writer Elizabeth Crisp contributed to this report.

Follow Jeff Adelson on Twitter, @jadelson.​