Mayors Want to Use Reservation for Flood Control
Preliminary Army Corps of Engineers' study shows large reservoir on South Mountain could alleviate flooding downstream
After the U.S. Army Corps of Engineers confirmed on Thursday that a bigger reservoir on the South Mountain Reservation could alleviate flooding along the Rahway, the Mayors Council on Rahway River Flood Control set out to convince Essex County that it’s a project worth pursuing.
If the river towns and Essex and Union Counties leave the project up to the U.S. Army Corps of Engineers, it could be several years before work could even begin and that is not palatable to mayors whose towns suffered a combined $75 million in damages.
“This has to be done sooner rather than later. When’s the next big storm going to hit? We don’t know,” said Millburn Mayor Sandy Haimoff, who hosted two meetings of the Mayors' Council, the Corps of Engineers and county officials on Thursday in Millburn.
The Corps presented plans on Thursday morning to the council that included creating a larger reservoir from Diamond Mill Pond north through Campbell’s Pond and almost to South Orange Avenue. The South Mountain reservoir would include a 70-feet high and 890 feet long detention dam and would normally be dry except when it rains and would take about two weeks to drain after a major storm, said Andre Chauncey, the hydrologic team leader at the Corps of Engineers.
Another alternative would be to lower the water level at the Orange Reservoir, which would also help, but not as much as creating the bigger reservoir, he said.
The Corps is studying the flood mitigation on South Mountain reservation as part of an overall flood mitigation plan to help bring relief to Cranford, which was the town along the Rahway hardest hit by flooding during Irene with more than 300 homes flooded.
But the timetable to get to the point of a feasibility study on the stormwater storage on South Mountain stretches to 2015 with no known estimated timeframe for Congressional approval.
Because of that, the Council of Mayors presented the report to the county, in the hopes of finding support in speeding up the process by doing it outside of the Corps.
Essex County Executive Joseph N. DiVincenzo, Jr. said he did not favor doing anything to the Orange reservoir, in part because of all the County facilities near it such as the Turtle Back Zoo, the arena and McCloone’s restaurant, but he could see that creating a larger reservoir at Diamond Mill could be beneficial and he would support it if county engineers approve of it.
“Essex County wants to be supportive, and we want to make sure Millburn gets relief,” he said. “But the bottom line is we have to see what kind of impact it would have on the reservation.”
He also said he understands the need to try to get the project done outside of the federal government.
“Anyone who has worked with the U.S. Army Corps knows we might not see it completed in our lifetime,” DiVincenzo said. “I don’t want to give false relief to folks.”
Arlene Kemp, the engineer for the City of Orange said that Orange wants to be a good neighbor and would lower water levels in the Orange Reservoir prior to a major storm, but would not allow the levels to be lowered all the time, as suggested by the Corps. However, she said, she also said she saw no problem with the enlarged reservoir at Diamond Mill and Campbell’s Pond, which is also on Orange property.
Millburn officials and residents are familiar with one of the impacts on the area if a larger reservoir was built -- the flooding Brookside Drive.
“But that road is closed anyway every time it rains because of flooding,” Haimoff said. “That is not a big deal.”
“We can live with a roadway being closed,” he said. “What else would there be? If it’s not going to affect anyone else, I’ll do it. I’ll sign it today.”
The report on the reservation is still very preliminary and much work needs to be done to identify what impact the expanded reservoir would have on the environment and the area, said project manager Rafit Salim with the Corps, who also warned that no flood risk management project can eliminate the risk of flooding.
"Given a long enough period of time, all project will experience an event that is larger than for which they were designed," she said. "Flood risk management projects can only reduce the frequency and/or severity of flooding and provide additional time to respond."
According to the Corps of Engineers’ preliminary study, the invisioned South Mountain Reservoir along with channel and bridge improvements would reduce flooding in Cranford by about four feet and reduce the river's flow by 20 percent, helping to alleviate flooding in Millburn and downstream, including Springfield, Union and Rahway.
Millburn’s engineering consultant Leo Coakley said the South Mountain Reservoir solution would offer “more benefits to more people” and all parties seem to be on “the same page” in that this needs to be pursued on a faster timetable than the U.S. Army Corps of Engineers can provide.
If the towns and counties pull this piece from the Corps project, he said, they could later be reimbursed possibly for part of it by the federal government if it helps the Corps of Engineers' Cranford project, Coakley said.
Additionally, he said, slowing the flow on the West Branch would help alleviate the back up on the East Branch when the tow branches merge at the I-78 bridge, which would help Springfield, Union and the South Mountain neighborhood of Millburn.
Meanwhile the Corps of Engineers is working on its plans for Cranford that include channel and bridge improvements and water retention projects there. The South Mountain study was added after the Mayors’ Council appealed to the Corps to look at it as a way to alleviate flooding in Cranford as well as all the towns between there and South Mountain Reservation.
Former Cranford Mayor Dan Aschenbach said it looks like flooding in Cranford could greatly be reduced with the reservoir project, and the towns and counties must keep working together to get it done, sharing the costs and finding state funding.
“We’ve identified a project here that will help,” he said. “We have to make the state understand that it has to be done, or we’ll get another $75 million in damage.”