The Susquehanna River in Wilkes-Barre had been forecast to crest near 41 feet, about the same height as the levee system protecting the city and surrounding towns, but the weather service said the swollen river was slowly receding from a level above 38 feet.
A broken gauge at Wilkes-Barre prevented experts from determining the exact crest, said weather service hydrologist Dave Ondrejik. But he said officials at the weather service and in Luzerne County are confident the river will not go back up because the waterway has already crested in upstream communities.
Luzerne County Commissioner Stephen Urban had said earlier Friday that the river crested at 38.83 feet around 9:35 p.m. Thursday. The weather service said that was the last reading pulled from the gauge before it broke but that the river likely ticked a bit higher.
Regardless, it was the second-highest level ever recorded for the Susquehanna in Wilkes-Barre.
As many as 75,000 residents in Wilkes-Barre and surrounding riverfront communities remain under a mandatory evacuation. Urban said the river is still far too high to allow people back home.
Near-record flooding along the Susquehanna and its branches - at levels not seen since Hurricane Agnes in 1972 - has killed five people and inundated hundreds of homes over the past few days. Rain from Tropical Storm Lee pounded the state earlier this week not long after Hurricane Irene soaked the same areas.
President Barack Obama declared a state of emergency in Pennsylvania early Friday, clearing the way for federal aid. Pennsylvania's lawmakers in Washington had urged the president to grant Gov. Tom Corbett's request for assistance.
Corbett on Thursday declared a Level 1 emergency - last done on Sept. 11, 2001 - and ordered state offices in Harrisburg, Reading and Scranton closed Thursday and Friday, affecting about 25,000 nonessential employees.
The Pennsylvania Emergency Management Agency said 14 wastewater treatment plants have been taken offline by flooding and residents were urged to stay away from flood waters over concerns about toxicity.
In West Pittston, which is near Wilkes-Barre but unprotected by the levees, several hundred homes were under water - many to the second floor, said former Mayor Bill Goldsworthy, now an official in Corbett's northeast regional office. Goldsworthy's own home was among those inundated.
It was the same story downriver in Plymouth Township, where floodwater swamped about 80 businesses and houses. Township Supervisor Gale Conrad said late Thursday it's the worst flooding her community has endured since Agnes. Touring Main Street by rowboat, she saw floating propane tanks, Dumpsters, and garbage and debris of all sorts.
The levee system stops just short of the township.
"I'm so disappointed there are no dikes," said Conrad, whose community has flooded repeatedly. "It makes our residents and businesses feel we don't matter. But we do matter, as much as any other community."
Farther down the Susquehanna River in Bloomsburg, flood waters on Friday exceeded the height reached by Hurricane Agnes by more than a foot and were expected to crest just short of the record set by a 1904 flood.
Columbia County Public Information Officer John Thomas said about a quarter of Bloomsburg is affected by flood waters and several homes have been swept off their foundations by the rushing waters.
"There's going to be a major damage assessment, I'm sure," Thomas said early Friday morning. Those things can't be determined right now because of the difficulty in getting to the places affected."
PEMA spokesman Cory Angell said Friday morning the state has begun moving resources, particularly swift water rescue personnel, from northeastern to central Pennsylvania as flooding upstream crests and subsides.
Mary Evans, 60, of Wilkes-Barre, was grateful that National Guard members helped sandbagged her home. She's never had water in her house but feared this time would be different.
Evans did not evacuate, preferring to stay behind to run pumps in her basement.
"We're trying to stick it out and stay here as best we can. If it gets too high, I guess we'll leave," Evans said. "We won't have a choice."
At least five deaths were at least partially attributed to flooding in central Pennsylvania, where hard-hit communities included Bloomsburg, Hershey and Lancaster.
Hundreds of roads across the eastern half of the state were closed by flooding. A nearly 40-mile stretch of the Pennsylvania Turnpike closed Thursday evening because rising waters threatened a bridge in Dauphin County, but the turnpike reopened in time for the morning rush hour after water levels dropped and engineers checked the bridge for problems.
Randy Pennell and Kathy Matheson in Philadelphia, Peter Jackson in Harrisburg and Genaro C. Armas in State College contributed to this report.