David Kilby, Managing Editor
CRANBURY Brainerd dam has needed minor repairs for years, but when engineers presented repair plans to the Township Committee Monday, residents wanted to know what is being done to prevent flooding and were not too concerned about the minor repairs needed.
”Over the past number of years, there’ve been issues with the dam,” Mayor David Cook said. “The state was going to fine Cranbury if we didn’t address the issues.”
Vajira Gunawardana, environmental engineer for Najarian Associates, gave a presentation on the plans for the dam repairs. From the onset, he made it clear the dam repair project will not be a flood control project.
”If it wasn’t about money, we could address the issue of the Irene-type event,” Mayor Cook said. “The rub is the cost is astronomical. We’re talking $9 million to handle something like an Irene. It would look like a Hoover Dam essentially. The current project, which will only cost Cranbury about $1.5 million, will address structural issues, but we’re trying to address flood issues as much as possible while working with the amount of money we have.”
The current spillway of the dam is 36 feet, and the spillway for the new dam would be 100 feet.
The concrete wall, built in 1991, is in good condition, Mr. Gunawardana said, but everything above it, such as the concrete cap, is in bad condition.
The typical one-year storm will not overflow into the road, but waters from a two- to 100-year storm would overflow onto the road, he said.
With the proposed design, the dam would be able to hold back waters of up to a 10-year storm, he said.
”This is very important for residents,” Mr. Gunawardana said. “This isn’t a flood control project, but by increasing the spillway, it is inherently decreasing the risk of flooding. But a 100-year storm will still go overtop.”
The project would replace the current concrete wall, cap and rail and remove the concrete beach on the other side of the road along Cranbury Brook.
The project also will provide more slope protection with large concrete blocks on the slope covered with soil, which will prevent some erosion. The erosion near the dam was so severe during Hurricane Irene that it caused the sidewalk and driveway of 1 N. Main St. to collapse.
The road will be lowered 6 inches, and its slope will be graded toward Cranbury Brook so overtopping water flows into the brook.
Najarian Associates will send the project plans to the Department of Environmental Protection in the spring. The hope is DEP will give approval within 90 days, and construction would begin in one year, Mr. Gunawardana said.
Only the half of the road being worked on would be closed, allowing cars to pass on Main Street during the entire period of construction. The sidewalks will be closed one side at a time. The water level of the lake will be lowered for the duration of the project.
The project is estimated at about $3 million, half of which will be paid by the county.
”To me, this really is not a solution,” said Suzanne Palocz, of 1 N. Main St., who had her driveway and sidewalk collapse in Hurricane Irene. “We’ve had many other floods not to speak of Irene”.
Other residents wanted a guarantee a fish way would be placed in the dam.
”If you’re the lowest dam in the system, the law is you have to put a fish way in,” said Stuart Long of Main Street.
He said while the township redesigns the dam, it should take the opportunity to find a place in it for fish to pass through.
”Fish ways don’t all work, but we’re going to make one that does here in Cranbury,” Mr. Long said.

