Mullica River Wetland Mitigation Site

GreenVest, LLC and Princeton Hydro, LLC worked together to restore a 33.89 acre parcel of land located in the Mullica River Watershed in the Township of Evesham in Burlington County, New Jersey. For a century, the land was used as cranberry cultivation bogs and was intensively manipulated to facilitate cranberry production. This included a network of earthen berms surrounding the cranberry cultivating bogs, a series of ditches and water control structures were to manage water onsite, and other agricultural infrastructure.

Although the site was highly degraded, it was bordered mostly by Atlantic white cedar dominated swamp and still contained four state listed species, including the state-endangered Timber Rattlesnake and the Pine Barrens Tree Frog, making it a priority site for restoration. The presence of these species influenced the design as it included provisions to incorporate habitat elements for these species.

Through the implementation of restoration activities focused on removing the site’s agricultural infrastructure, Princeton Hydro and GreenVest were able to restore a natural wetland system on the site. In addition, the restoration project reconnected the site to its floodplain and re-established a natural stream channel. The expansive, flat and wide floodplain wetland complex of the Alquatka Branch of the Mullica River provides floodplain connectivity for relatively frequent storm events and allows for a sustainable floodplain wetland complex in the former cranberry bog cells.

Additionally, the project involved innovative restoration techniques that required building consensus among local watershed protection groups and state and regional regulators, including New Jersey Department of Environmental Protection and the New Jersey Pinelands Commission. The project also incorporated a balance of both ecological and human health and safety benefits.

The restoration of the site focused on the establishment of several wetland types including emergent and forested wetlands based on the restored site hydrology. Restoration planting at the site took place in four primary areas: 1.70 acres of Atlantic White Cedar Swamp, 5.60 acres of Emergent Wetland, 8.53 acres of Forested Scrub-shrub Wetland, and 3.75 acres of upland and wetland transition area enhancement.

Plantings in the emergent wetland included 12,197 plugs of the following:

• Swamp milkweed
• Northern Long’s sedge
• Swamp loosestrife
• Canela rush
• Cardinal flower
• Golden club
• Pickerel weed
• Duck potato
• Woolgrass

The forested scrub-shrub wetland included 1,965 containerized plantings consisting of the following species:

• Red maple
• Black gum
• Buttonbush
• Leatherleaf
• Virginia Sweetspire
• Highbush blueberry
• Sweet pepperbush
• Inkberry
• Winterberry
• Maleberry
• Chokeberry
• Possumhaw

For the Atlantic White Cedar restoration area, 1.70 acres were planted with 718 containerized plants. These included 20% of the plantings as Atlantic White Cedar. The Atlantic white cedar (Chamaecyparis thyoides) component of the restoration project was designed to convert an existing portion of a cranberry bog to its historical ecological community. Atlantic White Cedar wetlands provide invaluable habitat to a variety of threatened/endangered species in New Jersey, including Pine Barrens Treefrog (Hyla andersonii), Barred Owl (Strix varia), and Timber Rattlesnake (Crotalus horridus) while also providing an array of ecosystem functions associated with wetlands including water storage, water filtration, and biological productivity.

In the end, the project restored 34 acres of a highly functioning forested wetland/upland complex and reestablished 1,600+ linear feet of historic headwater stream channels. The project significantly uplifted threatened and endangered species habitat. The entire restored stream reach has fully formed and has been stable since the end of the 2015 growing season. And, the project won the Bowman’s Hill Wildflower Preserve’s “2018 Land Ethics Award of Merit.”