Chatham's Passaic River Under 'Flood Warning' Through Thursday

CHATHAM, NJ — The Passaic River, which set records with Ida, is expected to experience “minor flooding” conditions through Thursday, according to the National Weather Service on Tuesday morning.

The National Weather Service also states the conditions at the Passaic River in the Chatham area could have a greater impact throughout Morris and Somerset Counties.

The National Weather Service issued multiple weather statements simultaneously for Chatham on Tuesday morning, among them a Hazardous Weather Outlook, Flash Flood Watch through 5 p.m. Tuesday, a Flood Warning - meaning flooding is imminent - through Tuesday at 4 p.m. and then a Flood Warning through Thursday at 2 p.m.

In its forecast for Tuesday, the Weather Service expects that daytime temperatures in Chatham should rise 62 degrees, with up to 2 inches of new rain possible. Overnight on Tuesday, temperatures are predicted to drop to 52, while the rain continues, accompanied by wind gusts up to 25 mph. Those gusts could stick around through Wednesday, as skies clear, with a high of 61,

As of 7:15 a.m. on Tuesday, the National Weather Service reports that the Passaic River is at 5.1 feet, with “flood stage” considered 6 feet. By Wednesday, the National Weather Service expects that the river will rise to 6.1 feet and remain at that depth through Wednesday for what is classified as “minor flood stage.”

In its Flash Flood Watch, the National Weather Service states the rain throughout Tuesday is expected to remain steady and heavy at times, with totals dropping between 2 to 4 inches and “locally higher amounts possible.”

With that, there could be “flash flooding of creeks, streams, urban areas and areas of poor drainage,” as a result of heavy rain, with the Weather Service encouraging residents tp follow the forecasts and “be prepared to take action should Flash Flood Warnings be issued.”

In the Flood Warning issued through 4 p.m. on Thursday, this is when the Weather Service predicts that the Passaic could reach 6.1 feet.

As part of this warning, the Weather Service has presented the following potential impacts that could occur if the river crests to a particular height, as follows:

• Impact...At 5.5 feet, Open areas adjacent to the Passaic River flood in New Providence, Chatham Township, and Berkley Heights.
• Impact...At 6.0 feet, Portions of the Shepard Kolluck Park in Chatham floods. River Road by Henry Drive is subject to closures.
• Impact...At 6.5 feet, The Central and Bridge Avenue bridges in Chatham Township are subject to closures. Edgewood Road is closed.
• Flood History...This crest compares to a previous crest of 6.1 feet on 04/02/2005.

From the remnants of Ida on Sept. 2, the Passaic River by Chatham set records, having reached 8.41 feet, which places its among the National Weather Service’s “Historic Crests,” for this segment of the river, only exceeded by 9.36 feet on Aug. 2, 1973.

To view the river’s current activity, as tracked by the USGS, click here.

Editor's Note: This story has been updated to clarify that the scenarios presented by the National Weather Service on potential street closures are presented only as possibilities, should the Passaic River crest to particular levels.

Questions or comments about this story? Have a news tip? Contact me at: jennifer.miller@patch.com.