Flooding help for Rahway River could be years away

File photo
Flood waters from the Rahway River during Hurricane Irene in 2011 turned South Avenue into a lake.

UNION COUNTY, NJ — With images of Hurricane Irma striking Florida dominating news coverage only two weeks after similar pictures from Hurricane Harvey’s devastation in Texas, local memories are being refreshed of Irene and Sandy — and the damage it wreaked.

While local officials are pushing for action along the Rahway River and its tributaries, Union, Essex and Middlesex counties may not see any improvements for another six years.

“The timeline is subject to when the U.S. Army Corps approves the chief’s report,” said Dan Aschenbach, who was mayor of Cranford during Irene and has since become the coordinator for the Mayors Council of Rahway River Watershed Flood Control. “All stakeholders — municipal government and NJ Department of Environmental Protection — have been urging that it be done as soon as possible.”
The chief’s report is a document reviewing studies and recommendations that began nearly two decades ago of the 81.9-mile Rahway River Basin occupying 35 percent of Union County from the Orange Reservoir to the Arthur Kill. The most recent push began more than two-and-a-half years ago following Sandy’s strike.

While the Mayors Council has pushed for construction to begin in the next six months, the timeline is dependent on many factors, and the original schedule dates completion for July of 2023.

On Sept. 3, the Mayors Council urged the U.S. Army Corps of Engineers and the NJDEP, which head the Rahway River Basin flood mitigation effort, to make this an eminent concern, expediting the process.

According to the U.S. Geology Survey, Hurricane Irene was undoubtedly one of New Jersey’s most costly disasters, with estimated damages totalling $100 million. The four-day storm, from Aug. 27-30, shut down local roads and highways making them impassable, it was responsible for damaging 200,000 homes and buildings. Power outages affected two million people, reported the USGS. Downtown Cranford was inundated, flooding a PSEG substation along the Rahway, which knocked out power to several surrounding municipalities for weeks.

Due to historic flood damage in Union County, a study on the river basin was authorized by Congress in March 1998. Following Irene and Sandy, another $1 million was approved to complete the studies, which have identified the Rahway River in Cranford and Robinson’s Branch in Rahway as two areas that experienced the most significant flood damages during major storm events.

The studies have reached the point of identifying tentatively selected plans, which have been chosen on a cost-benefit ratio.
Rifat Salim, project manager for the U.S. Army Corps of Engineers, noted in an interview with the LocalSource on Wednesday, Sept. 6, that Alternative 4a and Alternative 2a have been designated tentatively selected plans, with 4a currently under review.
It would ostensibly reduce flooding to Cranford, Millburn, Springfield and Union.

It will require the placement of two 36-inch diameter drainage pipes in the Orange Reservoir Dam. These pipes would allow for the release of water two days prior to a storm event, creating storage in the reservoir for excessive rainfall.
The dam will further be inspected and potentially modified to meet federal regulations.

The channels of the Rahway River that run through Cranford would be deepened and widened. These channel modifications will contribute to moderate downstream flow.

Alternative 2a would reduce flood damage along Robinsons Branch in Rahway. It is a non-structural approach that includes placing non-physical solutions onto structures.

Salim noted some of these measures include dry and wet flood proofing, ring walls and elevation.
After a review of the draft report, it must be finalized, presented and approved by Congress for authorization and appropriation of funding, Salim said.

“The cost remains uncertain if the outfalls can be done without major renovation,” Aschenbach said. “So the project cost could range at low end in $20 million range to $60 million in high range.”

According to the U.S. Army Corps website, flood risk management projects can only reduce the frequency and or the severity of flooding, providing additional time to respond. It does not eliminate flooding from happening.