Engineers Outline Alternatives to Control Flooding in Rahway River Basin
Saturday, May 31, 2014 • 6:00pm
MILLBURN, NJ – Any federal project to control flooding in the Rahway River basin is years away, and may or may not get done, depending on funding.
That was the message delivered by Col. Paul Owen of the U.S. Army Corps of Engineers at a public information session Thursday evening at Town Hall. More than 75 people crammed into the meeting space to hear the hour-long presentation.
“We’re still a few years away from a federally-approved project,” Owen noted.
The township is urging action to reduce chronic flooding of the west branch of the river as it flows through the downtown and South Mountain areas.
At the start of the session, Mayor Robert Tillotson read a letter from the Township Committee endorsing two alternatives the agency has been studying: Alternative 4, which involves channel improvements and modifications to the Orange Reservoir outlet, and Alternative 7, which includes modifications to existing structures in Cranford, ranging from floodproofing to elevating the buildings to buy-outs.
Millburn is not endorsing a third alternative, 6, a new dry detention structure in the South Mountain Reservation just upstream of Campbell’s Pond. A new dam that would be built would block off Brookside Drive, which could be altered to continue over the dam.
The cost for this alternative is estimated at $108 million.
Owen said his agency had identified 10 alternatives to mitigate flooding in Cranford, and as a result of running cost-benefit analyses, had found a potential federal interest in three of them. He went into detail about Alternatives 4, 7 and 6.
Alternative 4, which would carry a $68 million cost, would involve constructing new outlets at the Orange Reservoir, located just south of Northfield Road. Two 30-inch pipes would be installed that would allow for a drawdown ahead of storm events.
Alternative 7 would involve about 66 structures in Cranford. The alternative does not, however, do anything to mitigate flooding.
Several members of the audience asked questions about the concept of 100-year floods, assessing the environmental impact of various options and the possibility of reducing the amount of impermeable surfaces along the river. A handful of engineers from the agency sought to answer those questions.
Outside Town Hall, incoming attendees were met by representatives of Save Our Reservation, a grassroots organization opposed to building a dam in the South Mountain Reservation. They distributed stickers and literature.