Issue #15 

Spring 2007

The Basin Bulletin

Newsletter for Stakeholders of the Raritan River Basin

Prepared on behalf of the Raritan Basin Watershed Alliance

Corps and State Collaborate to Restore and Enhance Historic Property

By JoAnne Castagna, Ed.D

This past summer, a volunteer from the Somerset County Historical Society warmly welcomed Army Corps visitors at the historic Van Veghten House in Somerset County, N.J. He enthusiastically explained that the very room they were standing in was where Gen. George Washington danced the night away at a dinner party during the Revolutionary War.

The Corps visitors were a team who are performing the Finderne Wetlands Mitigation Project on the house’s property.  It was evident to the team that the state is proud of its history.  This was taken into account when the Corps’ New York District decided to collaborate with the state in 2000 on this mitigation project that is enhancing and restoring the land around the house to create wildlife habitats and a public park.

The Corps’ Finderne Wetlands Mitigation project is part of the Green Brook project designed to reduce flood damage in New Jersey’s Raritan River Basin in north-central New Jersey, in Middlesex, Somerset and Union counties.

The project is located on 130 acres of land along the Raritan River in Bridgewater Township, Somerset County.

According to Megan Grubb, Biologist and Coordinator, New York District, U.S. Army Corps of Engineers, the wetland mitigation work is satisfying the mitigation requirements that the Corps has with all of their flood damage reduction projects.

“The project is enhancing existing wetlands, forested land and grassland habitats on the site and creating 20+ acres of man-made wetlands to sustain wildlife and create an educational public park.” said Grubb.  

The land was used for farming crops and livestock from the late 1600’s to just a few years ago when Somerset County purchased it for open space preservation and park development. Years of farming had caused erosion problems on the land. One of these farms is the historic Van Veghten House. By 1699, the Van Veghten family farmed a huge tract of land that included all of the property now under construction at the mitigation site. The 18^th Century red brick Dutch farmhouse still stands on the bluff above the floodplain with a view to the Raritan River. 

The house, that’s presently occupied by the Somerset County Historical Society, has a rich history that includes sheltering Gen. George Washington’s Quartermaster General, Gen. Nathaniel Greene, during the Revolutionary War, while his soldiers camped nearby.

According to Grubb, the Corps has been working cooperatively since 2000 with the County’s Parks Commission to plan, design and construct the site.

Construction began by moving earth on the mitigation project in January.

The land was graded for approximately 2 months, around-the-clock, to prepare it for spring seeding. Grading sets the stage of the mitigation work by achieving a soil elevation that supports the water needs required for wetland plant growth. The soil in the wetland creation areas was then tilled using a 30-inch plow-bedding harrow, to create mounds and depressions, mimicking the uneven surface of a natural wetland. The soil was then fertilized and limed and this past spring nearly 100,000 trees and shrubs were planted. Habitat mitigation areas were also seeded with a mixture of native grasses and wild flowers.

Several wetland habitats, forested land and grassland habitats were enhanced or created to provide nesting and foraging habitats for a variety of birds, amphibians, reptiles, aquatic invertebrates, butterflies and mammals.

The public will be able to view these habitats by walking along a 2-mile nature trail created by the Corps.

The trail meanders throughout the site and has signs that educate the public about the habitats and the wildlife they are supporting, as well as provide facts about the nearby Van Veghten House.  Also on the site are two playing fields with parking lots and access roads, making the site a part of the Raritan River Greenway.

“Most of the mitigation work was completed in the summer of 2006.  Twelve acres of recreational area, such as the trail and playing fields, will be opened to the public in the spring of 2007 after the grasses and plants have had a chance to grow,” added Grubb.

What the project entails:

Wetland, Forested Land & Grassland Habitat Enhancement:

Forested Wetland: This is wetland that has deciduous woody vegetation with a tree canopy in excess of 20-feet in height. Approximately fourteen acres of existing forested wetland were enhanced by planting trees included oak, ash and sycamore and shrubs including summersweet, silky dogwood and high bush blueberry. 

Scrub-shrub Wetland: This is a wetland that has primarily woody vegetation that is less then 20-feet tall. Approximately eight acres were enhanced by seeding and planting the wetland to make it more desirable for various species of wildlife.

Emergent Wetland (Wet Marsh): Five acres were enhanced by seeding and planting the wetland to make it more desirable for various species of wildlife.

Riparian Forest (Corridor Forest): This is a forest that borders a river, in this case the Raritan River. Approximately 25 acres of Riparian Forest was restored by seeding and planting.  In addition, the Riparian Buffer, or the strip of woody vegetation along the river’s banks, was increased to 100-300 feet to create a habitat for wildlife that thrives in this type of environment including species of birds, mammals, reptiles, and amphibians. In addition, the increased buffer sustains shade cover for fish habitat’s, within the river.  In this buffer area, various shrubs and trees were planted including shrubs such as elderberry, spicebush and black haw viburnum and trees such as hickory and silver maple.  These trees were selected because of their shaggy bark at maturity that could provide a suitable roosting habitat for bats during the summertime.

Stream Restoration: An unnamed 800-foot stream, referred to as the “Finderne Brook,” runs through portions of the site. The stream was eroding and the Corps took steps to create a more natural water flow and restore its habitat. To improve the water flow, the floodplain, or area bordering the stream, was widened to prevent the stream’s banks from eroding and an undersized pipe culvert, that was constricting flow, was replaced with a natural bottom arched culvert bridge. To improve the stream habitat and stabilize the banks, the stream was graded, seeded with floodplain grass, planted with wetland plant cuttings, such as willow species, and covered with a degradable coir matting, made of coconut fiber, to stabilize riverbank soils until vegetation takes hold. In addition, to prevent soil erosion, supplemental riverbed stone material was placed in the stream. Also, the stones create a series of pools and riffles for fish and invertebrate habitats, such as crayfish and pickerel frogs that have already been sighted in the stream.

Grassland by Van Veghten House:

Thirty-nine acres of enhanced grassland has transformed the property around the Van Veghten House that overlooks the Raritan River. The grassland provides house visitors an unobstructed view of the vista across the floodplain towards the Raritan River. The floodplain was seeded with warm season grasses, including Indian grass and bluestem and wildflowers, such as ox-eye daisy, asters, and coreopsis that will support a population of pollinating birds and insects, and the meadow will be a foraging area for the resident fox and red-tailed hawk, as well as other birds and small mammals.

Wetland Creation:

Forested Wetland:

Twenty-one acres of pastureland was turned into forested wetland. The land was graded then the area was seeded with a seed mix of wetland plants and floodplain grasses, and planted with bare root and container plant material. Trees planted included oaks, ash and sycamore and shrubs planted included summersweet, silky dogwood and high bush blueberry.  In some areas the land was graded to create vernal pools, ephemeral spring ponding areas, used by salamanders, invertebrates, and frogs for breeding.  

Grubb provides these suggestions for others planning a mitigation project:

Contact plant nurseries early.  Do this to find out what species are available and to see if you can get the quantity and plant size you need for your project. 

Plan ahead when using native plants: If you plan on growing native species in your project, using seeds and cuttings collected directly from the area, it’s recommended that propagation activities be initiated at least two years in advance of project construction.

Consider practical storing of plant material on the site. Have a plan in mind for storing large quantities of plant material, especially bare root trees and shrubs on the site. The Corps’ construction contractor utilized an on-site refrigerator truck for storing.  Having the truck, which mimics a greenhouse by maintaining temperature and humidity levels similar to a nursery, allows you to store large quantities of plants and it extends the window of time cuttings can be stored on site for planting. Without the truck, the storing and planting of bare root material would have been limited to just 1-2 days for each delivery of plants.  The truck also preserved live stake material in its dormant state for a period extending beyond nursery availability.

Have project designers make repeated site visits.  Project designers should visit the project site several times during the design process because site conditions can change. Incorporating any necessary design changes prior to the construction helps to minimize construction time delays and costly modifications. They should also be involved team members during the construction process.

Collaborate with property stakeholders.  For example, the Corps reached an agreement with the State Historic Preservation Office to plant grassland rather then trees near the Van Veghten House in order to maintain the historic view from the house to the Raritan River. The Corps also reached an agreement with a local utility to plant unobtrusive vegetation in areas of the site to provide them continued access to overhead power lines on the site. 

Grubb said that the success of this mitigation project has encouraged her to seek out other sites in the area to perform similar work. “We are already observing wildlife on the site, including red tail hawks, great blue herons, painted turtles, northern water snakes, freshwater clams and a resident red fox.”

For more information about the Veghten House, please call the Somerset County Historical Society at 908-218-1281.

Dr. JoAnne Castagna is a technical writer for the U.S. Army Corps of Engineers, New York District.  She can be reached at joanne.castagna@usace.army.mil