Hickory Swamp – A Periglacial Land Form in East Brunswick, NJ
Article and images by Richard Sears Walling, Historic Preservation Planner
October 21, 2018
Hickory Swamp – at Hidden Wood proposed development site
Along the Sawmill Brook corridor, part of the greater Lawrence Brook Watershed and Lower Raritan River basin, remains a unique geological remnant from the Wisconsin Ice Age of more than twelve thousand years ago – Hickory Swamp. This landform is the northern-most example of Pine Barrens in New Jersey. Although the area has remained undeveloped since the time of the Lenape, a major apartment development threatens the destruction of this habitat and poses irrevocable harm to the Sawmill Brook.
The Wisconsin Glacier ended at what is now the large hill just north of Exit 10 of the New Jersey Turnpike, about eight miles north of the proposed development site. At this point, the glacier was one-mile high, having descended from a height of 3 miles high further north. Beyond this massive glacier was a polar desert, with sand and loess being blown in by the wind from the north at a rate of 65 knots (75 miles) per hour. Wherever sand was deposited in enough quantity to create a habitat, sand barrens were formed. There are barrens at Albany and Long Island in New York, and the northern-most Pine Barrens in New Jersey is the wooded area along the portion of the Sawmill Brook, which runs through Harts Lane.
According to Mark Demitroff, internationally known and respected expert on Pine Barrens geology, this area was formed by proglacial and periglacial activity during the Late Pleistocene. The two dunes present at the site represent a unique periglacial landform resource. These high terraces served Paleo-Indian and later native peoples as natural high ground overlooking Hickory Swamp and the many nearby ponds. Associated natural ponds at Hickory Swamp may, upon further site examination, turn out to be spungs. Professor Demitroff describes the Hickory Swamp area as “having potential value in the study of Carolina Bays, of which Pine Barrens spungs are a variant of. Hickory Swamp ponds mark a transition from a proglacial to a periglacial realm; a little understood interface; at least in a North American context.”
Due to the environmental restrictions of the forty-five acre site proposed for development, there is a checker-board pattern of existing conservation areas. If the site is turned into a literal mini-city (net density of the developable land is over fourteen units per acre, with six hundred parking spaces), these scattered conservation areas will be further fragmented, and partially destroyed by construction activities.
Dr. Emile DeVito, Manager of Science and Stewardship for the New Jersey Conservation Foundation finds that “portions of the watershed which are currently in conservation easements will likewise be degraded and lost. By placing high-density development and impacting current slopes and water-drainage systems that have existed for eons, those natural communities of both fauna and flora will be isolated into small pockets of helter-skelter islands with no chance of moving beyond those small confines. The direct result is obvious, the very intent for which those conservation easements were created in the first place will be negatively affected, and the animal and plant life will be diminished as time goes by, to the point of virtual extinction from their habitat.”
The fight to preserve this unique landform is spearheaded by the Preserve East Brunswick Pine Barrens Coalition. The Sierra Club and the Lower Raritan Watershed Partnership have provided letters of support for conservation of this site, and it is hoped that this forty-five acre tract will be preserved and added to three adjoining preserved open space parcels, all connected by the Sawmill Brook corridor.
The Hidden Oak Woods development application is scheduled for a public hearing before the East Brunswick Planning Board for December 5, 2018 at 8 p.m. in the East Brunswick municipal courtroom. At that time, it is anticipated that the applicant will conclude its presentation and the Coalition will then present the counter case against the proposed mini-city. Interested persons and organizations are welcome to attend. For further information, please find the Preserve East Brunswick Pine Barrens Coalition on Facebook, or email firstname.lastname@example.org. Together, we can ensure that this vestige of our natural history will be preserved for future generations.