PHILADELPHIA (AP) – Residents along many eastern Pennsylvania waterways continued to prepare for the worst of Tropical Storm Irene's wrath that may be to come as swollen waterways continue to rise.

Along the Delaware River, communities readied for the water, with Easton and New Hope bracing for major flooding that the National Weather Service said could come Monday morning or afternoon if the river crests to 31 feet, or nine feet above flood stage.

Emerging from Irene, the hurricane that weakened to a tropical storm, Pennsylvania residents and emergency officials are keeping a close watch on swollen rivers expected to overflow from the rain Irene let loose overnight Sunday in New York and New England.

Across the eastern half of the state, swollen creeks and rising rivers, already filled to capacity by an abundantly wet August, threatened to spill over their banks and cause more damage by flooding than the wind did.

In Allentown, Mayor Ed Pawlowski asked residents to conserve water for the next 48 hours as water main breaks are repaired.

Officials in Easton's Forks Township have asked residents living near the Delaware river to leave their homes. Lower Bethel Township emergency management coordinator Marvin McCammon said about 100 people in that community will be urged to evacuate several hours before the river reaches flood level on Monday.

In several school districts, where the new academic year was scheduled to begin Monday, classes were canceled because of Irene. Among the districts postponing the start of the school year until Tuesday were Easton, Central Bucks, Coatesville, Kutztown, Nazareth and Unionville-Chadds Ford.

Easton Mayor Sal Panto Jr. said it's more than likely the waterfront of the city of nearly 27,000 could be inundated, but as to how far the water may stretch, it's anybody's guess.

The city has flooded before – five times since 1996 the river has crested over 30 feet, The Express-Times reported – but the city is ready. No mandatory evacuations have been issued but residents who live in low-lying communities know that it's part of living there.

"We've had higher. We've had 37 feet," Panto told The Morning Call of Allentown. Optimistically he predicted that flooding would be moderate.

On Sunday, it was another river, the Schuylkill, that wreaked havoc, cresting to more than 15 feet in Norristown and inundating homes with muddy water and flooding streets in Philadelphia, too.

Bud Buono's house on stilts was surrounded by water, reachable only by watercraft. Buono, 51, said he'd gotten everything out of his ground-floor basement ahead of the flood. But neighbors with older, bungalow-style houses weren't so fortunate – they had water in their living spaces.

"You take the good with the bad down here," said Buono, who's lived on the Schuylkill for 30 years. "It's a different breed of people."

In Philadelphia, the Schuylkill flooded low-lying streets and crested at 13.56 feet just after 2 p.m. – below the 15-foot level that city officials had forecast but still well over flood stage – and fell back to 13.42 feet. It began dropping as night fell.

Irene has contributed to at least four deaths in Pennsylvania and left hundreds of thousands of Pennsylvania customers in the dark.

Though the skies began to clear, and the sun peeked through in some places, the threat of flooding was paramount. So were fears about complacency, too.

Gov. Tom Corbett cautioned that residents across the state needed to be mindful of the risk of flooding.

"We have been very fortunate to this point," Corbett said at a news conference. "Even though it's clearing up out there, we're not done yet."

Statewide, about 706,000 people lacked power late Sunday afternoon, according to Ruth Miller, a spokeswoman for the Pennsylvania Emergency Management Agency. The tally included 375,000 PECO electric customers in the Philadelphia area and 230,000 PPL Corp. customers in Allentown and points north.

Some PECO customers may not get their power back for seven to 10 days, according to spokeswoman Karen Muldoon Geus.

"We're really working around the clock to try to get our customers back on as quickly as possible," she said. "Mother Nature has not been kind to us the last couple of days."

PPL said Irene damaged transmission and distribution systems, flooded substations, and knocked down countless power lines – a total of 3,500 individual cases of trouble.

The state emergency agency attributed four deaths to the storm. Falling trees crushed a man in a camper in Luzerne County and a man in a tent in Dauphin County. A motorist skidded over an embankment and hit a tree on the Pennsylvania Turnpike in Carbon County. In Monroe County, a man was killed when a tree fell on him in his yard.

At Fort Indiantown Gap, the Pennsylvania National Guard monitored the storm and response in real time, plastering maps and operational data on a massive screen occupying much of one wall in a basement command center.Rising waters will continue to be the chief concern for rescuers. Even as the storm moved out of Pennsylvania, Guard officials monitored rainfall totals in New York – a major factor in downstream flooding.

"You're never quite sure when you're out of the woods," Col. Robert Hodgson told The Associated Press.

Rubinkam reported from Norristown. Randy Pennell contributed to this story from Fort Indiantown Gap.

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