Officials still do not have a clear idea of the city's drainage capacity as Hurricane Harvey barrels toward the Texas coast, likely sending heavy bands of rain over New Orleans this weekend.

More information about exactly how much water the S&WB's pumps can remove from the city, and how fast, is expected tomorrow morning, the day Harvey will make landfall, Mayor Mitch Landrieu said during a morning press conference.

Landrieu remained vague about what circumstances could trigger an evacuation.

Though far from New Orleans itself, Harvey is expected to drop between 5 inches and 10 inches of rain on the city, and possibly twice that in some areas, Landrieu said.

That could cause flooding even in the best of circumstances, Landrieu said. But with more than a dozen S&WB drainage pumps offline and only two of the five turbines that power them running, the impacts of heavy rains could be devastating.

Landrieu said officials still do not know what the city's current pumping capacity is with 15 of its 120 pumps offline but said engineers are expected to provide an estimate on Friday.

The city's normal plans call for an evacuation if a Category 3 hurricane is set to strike. 

During planning sessions with FEMA and state officials, the Landrieu administration has been considering scenarios that could trigger an evacuation solely for rain because of the diminished capacity of the drainage system.

But asked whether an evacuation could be called for Harvey, Landrieu said, "The answer is 'not yet.' "

Latest forecasts indicated the storm would make landfall along the Texas coast at some point on Friday, likely bringing significant rainfall to much of Louisiana. 

"All of us need to lean forward, to be alert, to clean catch basins and be prepared," Landrieu said.

The city has been working with federal officials to establish an evacuation plan for areas is significant rain strikes while the drainage system remains at a diminished capacity. He addressed recent reports that the Lakeview area would be the first to be evacuated in that instance, but did not confirm report. 

"[That's] one of many scenarios" being considered, he said. 

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