By Donald Gilpin

“Sustainability,” “resiliency,” “stormwater control,” and “flood mitigation” are words appearing with great frequency in current media and engineering studies, and a look at descriptions of infrastructure projects underway in Princeton reveals the predominance of these environmental concerns.

The February 26 Municipality of Princeton newsletter reports on plans to replace six old and out-of-date storm drains (culverts) in town. The project is in the early design stages and may take a year or two before it is completed.

“These culvert replacements are part of our commitment to sustainability, stormwater control, and flood mitigation,” the newsletter states. “The holistic approach of managing runoff where the rain falls, maintaining a robust storm sewer system, developing storm water mitigation measures, and protecting our floodplain provides for a safer, cleaner environment for our residents (and everyone who lives downstream!).”

This culvert replacement enterprise is only one of numerous projects currently in progress under the supervision of the Princeton Municipal Engineering
Department.

“Everything being done now is being done with an eye toward resiliency and sustainability,” said Assistant Municipal Engineer James Purcell. “For each one of the projects that we have going we look at the environmental impact and what we can do to be less impactful and reduce our carbon footprint.”

He elaborated, “New regulations from the New Jersey Department of Environmental Protection, that are long overdue, require that things be designed with the idea that climate change is here, so our stream modeling to determine the flows in the streams is going to be based on projected rainfalls 75 years from now. In the past, design was based on historical data, but now we’re going to be designing our stormwater management and flood plain management based on projected future data.”

Before digging into details on several more of the municipality’s current infrastructure tasks, Purcell raised a warning flag concerning two potentially disruptive projects not under the auspices of the municipality: a PSE&G

gas main replacement project on Nassau Street and a Mercer County culvert repair project on Cherry Hill Road.

Starting next Monday, March 4, PSE&G will be working at night on Nassau Street replacing gas mains. Purcell said that the municipality would be providing information later this week alerting local residents to expect noisy nights on Nassau Street for the next few weeks.

Also starting on Monday, March 4, Cherry Hill Road will be closed as the county works on culvert repairs, possibly for a full month.

Purcell noted that the Witherspoon Street Improvement Project is entering its third and final phase, from just north of Leigh Avenue to just south of Valley Road, with construction scheduled to begin on March 4 and completion by Thanksgiving.

“We’re trying to make it a more pleasant street for pedestrians and bicyclists, so that people get out of their cars,” said Purcell. In addition to roadway and sidewalk improvements, he noted that a demonstration roadside garden that will be fed by stormwater runoff from the street is being constructed between the Municipal Building parking lot and the street.

Princeton’s Witherspoon Phase 1 project recently won the Project of the Year Award from the Professional Engineers’ Society of Mercer County.

Meanwhile, the Nassau Streetscape project is still in the design stages but will soon be gearing up to make sure all is ready by 2026 to welcome visitors for 250th semiquincentennial celebrations. Key goals of the work are to revitalize the streetscape and improve the pedestrian experience on the north side of Nassau Street.

Other municipal engineering projects underway include rehabilitation of a sanitary sewer system that serves neighborhoods around Cherry Hill Road, State Road, and Mt. Lucas Road between Valley Road and Ewing Street; improvement of Mt. Lucas Road from Stuart Road East to Poor Farm Road, expected to be constructed this summer; the Rosedale Road Safe Routes to School Project, funded by a federal grant to improve pedestrian and bicycle facilities to Johnson Park Elementary School, moving into preliminary design stage this spring; and the sanitary sewer pump station upgrade design study.

Also on the agenda in the coming months are projects to improve Terhune Road, funded by grants from the New Jersey Department of Transportation; Dickinson Street, Alexander Street, and University Place improvements; and the extension of the Cherry Hill Road shared-use path.

Purcell pointed out that the Municipal Engineering Department had inventoried all the roads in town for surface distresses, and, with the help of a consultant, had made recommendations about which roads should be approached first. In addition to that they will be piloting a treatment called “pavement preservation.”

In resurfacing a roadway, usually two inches of existing asphalt are taken up and two new inches of asphalt are laid down. With pavement preservation no asphalt is removed, but instead a thin overlay is applied on the appropriate roadway.

“It saves a lot of money,” said Purcell. “And it’s more environmentally sensitive,

Because we’re not pulling up the old asphalt that would go into a stockpile somewhere and sit there forever, and putting down new asphalt. Instead, on two streets, we’ll be putting down a thin overlay. Hopefully everybody will appreciate that and hopefully we’ll be doing more of that.”