Hurricane Irene has departed the Delaware Valley, but created dangerous flooding conditions in southeastern Pennsylvania and southern New Jersey in its wake.

More than 600,000 people in the region are also without power.

Irene lashed Philadelphia with torrential rains; while prompting the exodus of thousands of Jersey shore residents inland to escape Irene’s wrath.

On Saturday night, Philadelphia Mayor Michael Nutter declared a state of emergency – the first in the city in 25 years.

This is one of the worst storm events that has hit Philadelphia in the last 50 years, he said.

The Philadelphia International Airport remains closed, while the SEPTA mass transit system is still shut down.

The National Weather Service has placed the entire region under a flash flood warning until 11:30 a.m. Sunday.

According to local Philadelphia media, the inland suburbs surrounding the city fared worse than the Jersey shore in terms of flooding. Rising waters have trapped people in their cars and homes in Upper Moreland, Abington, Willow Grove and other parts of Montgomery County.

The Schuylkill River was overflowing its banks and is expected to crest at more than 15 feet by this afternoon, prompting major flooding.

Rising water from the Schuylkill have swamped Kelly Drive and Chestnut Street near the Chestnut Street bridge in Philadelphia; while waters flowing from The Delaware River turned the intersection of Spring Garden Street and Delaware Avenue into a swimming pool.

Chester Creek near Upland. Pa. is already 8 feet about flood stage and continues to rise; Darby Creek has overflowed, flooding McDade Boulevard in Darby Borough.

Major flooding is expected to continue Sunday along at New hope and Easton along the Delaware River.

Due to flooding fears, many townships in Bucks County have declared states of emergency.

PECO, the largest electric and natural gas utility in Pennsylvania, said 297,000 of its customers are out of power; PSE&G reported 230,000 people without power; while Atlantic City Electric said its figure was 83,960.

Service may not be restored immediately.

“Our restoration time that we're seeing now could be one to two weeks for some, depending on how much damage there is in the area, said a PECO spokesperson.

The ground is completely saturated. We've gotten a ton of rain, and damaged trees with branches are falling on power lines. On top of that, we have cleanup to do.

Other reports of local damager include: a house in North Philadelphia Sunday collapsed due to heavy rains, but no one was hurt; a twister was reported in Vineland, N.J.