The Passaic, which had washed over the bridge, swept through the once-booming factory town of 150,000, flooding the downtown area and forcing hundreds to evacuate. More than 100 people had to be rescued from the rising waters after the storm.
"You know, it could have been worse. But we should not underestimate the heartache that's going through a lot of these communities, affecting a lot of families," Obama said.
In nearby Wayne, the president made his way down Fayette Avenue, walking past flooded homes, the garage doors open. Piles of water-damaged debris littered the curb.
"Everybody's going to be working hard to help you recover," Obama told one woman as he put his hand on her shoulder.
The Passaic crested at twice its flood stage at a record 14 feet, depositing debris and muddy water stains on buildings and homes across Paterson.
"The entire country is behind you," Obama said after viewing the destruction. "We are going to make sure that we provide all the resources that's necessary in order to help these communities rebuild."
He pledged to people all along the Atlantic Coast who were affected by Irene that he won't allow "Washington politics" to get in the way of bringing federal help.
The White House told Congress late last week that there's a need for more than $5 billion in additional disaster relief money, not even counting the billions expected from Irene.
The Obama administration says that under the terms of last month's budget deal, Congress can provide more than $11 billion in disaster aid next year without finding offsetting budget cuts, as demanded by House Majority Leader Eric Cantor, R-Va., and other Republicans.
Before Thursday, the Obama had requested just $1.8 billion for the government's main disaster relief accounting. Some lawmakers complained that billions more were needed to help states rebuild from a string of hurricanes, floods and tornadoes.
The Federal Emergency Management Agency has less than $800 million in its disaster relief fund to pay for the immediate for Irene victims through September and the agency is putting on hold new rebuilding projects.
There seems to be little hope that the FEMA bill and the money to replenish disaster accounts will be enacted by the Oct. 1 deadline.
Yet Obama said he wanted to "make very clear we are go to meet our federal obligation."
He started his tour with a helicopter flight from Newark to Fairfield, a suburb about 10 miles west of Paterson. His motorcade brought him to the residential area in Wayne hit hard by the flooding of the Pompton River, which flows into the Passaic.
While Obama visited the Northeast, federal officials kept close watch on Tropical Storm Lee, which was dumping torrential rains across the Louisiana and Mississippi coasts. That area is still recovering six years after Hurricane Katrina.
White House spokesman Jay Carney said the administration is concerned about what "has been and will be a significant amount of rainfall."
Paterson, N.J.: http://www.patersonnj.gov/