Tidmarsh Farms Wetland Restoration

The Tidmarsh Farms Wetland Restoration (2010-2016) was the second ecological wetland restoration of cranberry farmland, and the largest freshwater wetland and river restoration ever undertaken in Massachusetts. It was followed in 2020 by the restoration of Foothills Preserve and Manomet Brook, both former portions of the Tidmarsh Farms property. In all, the land protection vision initiated by Tidmarsh Farms beginning in 2008 resulted in the conservation of 610 acres of former cranberry farmland in Plymouth, MA. In 2017, following the wetland restoration of the eastern farm, Tidmarsh Farms sold the 485 acres east of Beaver Dam Road to Mass Audubon to create the Tidmarsh Wildlife Sanctuary, and the 128 acres west of Beaver Dam Road to the Town of Plymouth who renamed this property Foothills Preserve.

Tidmarsh Farms was incorporated by Evan Schulman in 1982 during the purchase of a cranberry farm west of Beaver Dam Road, from Gary Richmond (85 Beaver Dam Road.) Several smaller farms across Beaver Dam Road were also acquired at this time. In 1984, Tidmarsh Farms purchased the large cranberry farm east of Beaver Dam Road from Cumberland Farms. Subsequently, Tidmarsh Farms acquired a narrow strip of land that abutted the western farm and ran up to the top of Pine Hills. All told, prior to 2017, Tidmarsh Farms encompassed over 50% of Beaver Dam Brook and over 15% of the Beaver Dam Brook Watershed. In 1989, following extensive farm renovation, the Farms delivered 32,000 barrels of cranberries, or over 1% of Ocean Spray’s crop.

In 2008, due to a confluence of circumstance, the owners of Tidmarsh Farms decided to try to conserve and protect this farmland and, following the example of Eel River, to restore the cranberry growing areas to wetlands. In 2010, the farms signed a conservation and restoration easement with the USDA Natural Resources Conservation Service (NRCS.) These former bogs receive ground and surface water from Fresh Pond, the Arm, cranberry farm runoff and groundwater from Little Island Pond, and the headwaters stream that once supplied the Beaver Dam Pond, the 35 acre principal reservoir for the cranberry operation. With the USDA NRCS easement in place, Beaver Dam Pond was drawn down to the consternation of some of its abutters.

Restored wetland. Photo by Eric J. Heller.

The 225 acre ecological wetland restoration of Tidmarsh Farms became a priority project with the Division of Ecological Restoration in 2011. The project attracted the support of many partners including Living Observatory (LO.)

During active restoration (2015-6), eight dams and water control structures were removed. At the northern extent of the growing area, where the cranberry bog transitions to a red maple swamp, a double culvert was removed and the stream was redirected into the original stream channel, that meanders through the Red Maple Swamp. A bridge was installed at this location to provide east-west passage of pedestrians, as well as maintenance vehicles. An undersized culvert at the Arm was replaced with a larger culvert.

One of the most difficult challenges project designers and engineers face in trying to transition a cranberry farm back to natural wetlands, is how to overcome the agricultural legacy of regular sand applications, which over time, separate the growing platform from the water table. At Tidmarsh, as on other cranberry farms, this sand layer was approximately 2 feet deep and interspersed with relatively impermeable layers of leaf drop. Restoration actions included adding riffles in the stream channel to raise the water table, and the production of microtopography using excavators, or pit and mounding of the sand, to break up the dense cranberry mat and expose some of the underlying peat across approximately 100 acres of the cranberry growing surface.

In addition to these actions, over 3,000 pieces of woody debris were introduced to the stream channel and the growing surface. Two flow-through ponds and several off-channel depressions were also constructed, and over 20,000 native plant species were planted, including over 7,000 Atlantic White Cedars.

Prior to these research actions, many LO research projects were initiated by academic and agency researchers. These studies, based on initial hunches, serve to quantify some of the presumed benefits of these wetland restorations on ecological variables such as: water quality, soil formation, microtopography, and the increased diversity and abundance of plant and wildlife species. The installation of an experimental sensor network that includes dense arrays of environmental sensors as well as cameras and microphones has created a unique record of change over time.

Date Completed: 2016

Owned by: Tidmarsh Farms until 2017. Currently owned by Mass Audubon

Restoration Area: ~ 225 acres

Highlights:

Largest freshwater restoration in Massachusetts to date
With Foothills Preserve occupies 15% of Beaver Dam Brook watershed and 50% of the stream channel
8 dams removed
7000+ Atlantic white cedar planted
Living Observatory collaborative initiates studies of water quality, soil formation, increase in diversity and quantity of plant and wildlife species.
Living Observatory collaborator at the MIT Media Lab develops a state of the art experimental sensor network to capture a visual, audio and environmental record of change over time
E-bird hot spot

In 2017, following active restoration, the portion of the Tidmarsh Farms site east of Beaver Dam Road was sold to MassAudubon, who established the Tidmarsh Wildlife Sanctuary. In 2020, Mass Audubon removed the final dams on the Sanctuary property and restored Manomet Brook (see Foothills Preserve) in 2020.

Partners: Tidmarsh Farms (Landowner); MA Fish and Game; Division of Ecological Restoration (Manager); USDA Natural Resource Conservation Service (NRCS); Wetlands Reserve Program; US Fish and Wildlife Service (USFWS); National Oceanic and Atmospheric Administration (NOAA); Massachusetts Environmental Trust; American Rivers; Gulf of Maine Council on the Marine Environment; Massachusetts Bays Programs; Town of Plymouth; InterFluve Inc. (project engineer;) SumCo Ecological Services (construction contractor); Mass Audubon; Manomet Center for Conservation Science; North and South Watershed Association; MIT Media Lab; MIT Sea Grant; Mount Holyoke College Restoration Ecology Program; University of Massachusetts - Boston; University of Massachusetts - Amherst; Bridgewater State University; Salicicola.com; Acoustic Footprint; Intel Corporation; & local volunteers.

Awards: Gulf of Maine Visionary Award; American Council of Engineering Companies Silver Award, Society of Ecological Restoration