Mid-city resident Dianne Mason, center loads a shopping cart full of water with help from her great-grandson Treyvon Tillery, age 9, right, into her truck at Costco in New Orleans, La., Thursday, Jan. 18, 2018. Boil water advisories are in effect for the east bank of New Orleans and Jefferson Parish and could last more than a day officials said Thursday morning.

Advocate staff photo by MAX BECHERER

New Orleans officials urged residents Sunday to continue curtailing water usage for "one more day" in order to stave off a possible loss of pressure great enough to trigger another boil-water advisory as tens of thousands go back to work and school Monday.

Also Sunday, officials announced that Orleans Parish public schools and Archdiocese of New Orleans schools would reopen Monday, except for individual campuses still experiencing issues with water pressure or other vital equipment.

City Hall and other government offices will be open. 

By Saturday afternoon, boil-water advisories had been lifted in Orleans and Jefferson parishes following days of a hard freeze that burst hundreds of pipes and prompted tens of thousands of residents to run their taps to try to prevent such mishaps.

On Sunday, officials announced the water pressure was "continuing to climb" but cautioned the good news could be short-lived if locals weren't careful to limit nonessential activities like washing cars, watering lawns and even running dishwashers.

The New Orleans Sewerage & Water Board reactivated a long-quiet Twitter account to better urge residents to help protect the city's fragile water system.

Richard Rainey, the agency's communications director, said residents should be able to resume normal usage by Monday.

No limitations were in place in Jefferson, where water pressure on Saturday was at 50 pounds per square inch, parish Chief Operating Officer Keith Conley said.

New Orleans, by contrast, continued even Sunday to hover worryingly close to the 15 psi threshold that triggers a boil advisory because it can allow contaminants to enter the system, according to the S&WB.

The boil-water advisory began Wednesday night in New Orleans East. By Thursday, it spread across the entire east bank of both parishes as water systems struggled to keep up with demand that had skyrocketed as freezing temperatures gripped the region the early part of the week, shutting down roads and businesses and causing pipes to break or customers to run their faucets for hours on end.

The spike in usage meant the S&WB by Saturday was pumping about 158 million gallons of water a day, up from its normal figure of about 135 million gallons.

Before many leaks had been fixed and while tens of thousands of customers were still running their taps, the S&WB was pumping up to 177 million gallons a day, officials said.

On Friday night, the advisory was lifted for most of New Orleans, and Jefferson Parish followed suit Saturday morning. The advisory in New Orleans East was lifted Saturday afternoon, meaning the water was safe to drink throughout both parishes.

Officials in St. Charles Parish had stopped asking residents to limit water use by Friday. The requests also stopped in St. Bernard and St. John the Baptist parishes by Sunday morning.

In New Orleans, as pressure remained a problem, officials had asked many large water users, including hotels and industrial plants, to limit consumption.

While most Orleans Parish School Board and Recovery School District schools were expected to be open Monday, Joseph A. Craig Charter School, 1423 St. Philip St., would stay closed, according to OPSB spokeswoman Dominique Ellis, who advised that additional campus closures could be announced as late as Monday morning.

In the meantime, frustrated residents continued to grumble on social media after many had limited access to potable water for days and had to hold off on normal household chores even after the freezing weather ended.

S&WB officials seemed to notice the griping as they took to the newly reactivated Twitter account to offer thanks and encouragement.

"We appreciate your patience," officials said via Twitter on Sunday afternoon. "We know it's tough."

Follow Della Hasselle on Twitter, @dellahasselle.