TIDMARSH FARMS / BEAVER DAM BROOK RESTORATION PROJECT
Tidmarsh Farms and its partners seek to achieve a comprehensive ecological restoration of Beaver Dam Brook and approximately 250 acres of the surrounding wetland system. Encompassing a significant portion of the South Coastal Watershed, the project will restore over 3.5 miles of high-quality cold-water sinuous stream and wetland habitat including the length of Beaver Dam Brook from its spring-fed headwaters to the point at which the brook exits the property at Route 3A. Project goals include: unobstructed headwaters-to-ocean fish passage and habitat for diadromous and resident fish; improved water quality within the watershed; nurturing diverse wildlife habitat across the property; significant planting of Atlantic White Cedar; system-focused academic study related to target habitats; on-site and remote public access to ever changing wetland processes; a variety of educational initiatives that will build new skill sets in the community.
Anticipated schedule: Design/permitting: 2011-2012; Restoration 2013-2014
Benefits: The benefits of restoring such a large site – a significant portion of an entire coastal watershed – are numerous. The project is expected to reduce nutrient loading and improve downstream water quality for the entire watershed by lowering the overall temperature of the stream channel, increasing dissolved oxygen concentrations, and increasing hydrologic residence times contained in ground water. Further, the project will enable free fish passage upstream from White Horse Beach and Bartlett Pond to the headwaters area (true ocean to headwaters passage); give rise to diverse plant and animal communities over a landscape now dominated by cranberry cultivation; and, provide significant carbon sequestration via wetland restoration including likely over 50,000+ individual plantings. This site is designated as part of a “Critical Supporting Watershed” on NHESP “Living Waters”.
What has been accomplished so far (timeline in brief):
2010, The owners placed permanent conservation and restoration easement on 192 acres of former cranberry bog through the USDA NRCS Wetland Reserve Program. This easement required that the owners to retire these bogs from farming, and restore them to productive wetlands.
2010, the owners met with Alex Hackman of the Ma. DFG, Division of Ecological Restoration, and agreed with Hackman that a process-based restoration would provide the best possible approach to restoration of Beaver Dam Brook and the adjacent flood plain. Following that decision, two preliminary conceptual studies were completed. These studies were framed by the mission of restoring the natural watershed processes – specifically the natural movement and flux of water, sediment, organic matter, nutrients, and sunlight/temperature – that are critical to forming and maintaining cold-water habitat, sustaining connectivity, and encouraging the unimpeded exchange of energy and materials that ultimately produce ecological integrity. The first of these studies, commissioned by MA DFW Division of Ecological Restoration and completed by Interfluve, Inc., recommended a comprehensive approach to the river channel including: removal of two dams at the headwaters; re-construction of the stream channel and adjacent floodplain through the retired cranberry bogs; re-watering of the floodplain forest, and extensive planting of the riparian corridor in order to increase biological diversity and integrity of what is now essentially a monoculture (cranberry). The study builds on this firm’s experience in restoring the Eel River Headwaters Restoration. A second study by the Horsley Witten Group looked at issues of groundwater flow and possible alternative treatments for Beaver Dam Pond.
In the fall of 2010, shortly after signing the easement with NRCS, the owners of Tidmarsh Farms dewatered Beaver Dam Pond, a man-made reservoir that no longer served its historic agricultural function. Neither the dam, which was failing, nor the reservoir, were included in the NRCS easement. Continued maintenance of the Beaver Dam Pond represented a cost and a liability to the owners. Releasing the impounded water had an additional benefit of allowing headwater stream to seek its preferred channel and allowing the natural embankments to dry, thus potentially saving many $$ to the future restoration actions. In the late summer-fall of 2011, at the request of the Plymouth Conservation Commission, the owners submitted an NOI and were issued an order of conditions acknowledging this configuration of the headwaters.
2011: The project applied for and received funding from 3 programs for the engineering design/permitting phase of the restoration: GOMC-NOAA Habitat Restoration Grants Program, American Rivers-NOAA Community-Based Restoration Program, and Massachusetts Environmental Trust. Alex Hackman of Mass DFG Division of Ecological Resources took the lead on grant applications for the first two grants; Brian Graber of American Rivers took the lead on a grant to Massachusetts Environmental Trust.
Tidmarsh Farms/Beaver Dam Brook project became an approved Priority Project in the Department of Fish and Game’s (DFG) Division of Ecological Restoration (DER).
2011-2012: DER and American Rivers issued an RFP for the engineering design and permitting phase of the project. The contract was awarded to Interfluve, Inc., the consultant that developed the engineering designs and implemented the Eel River Restoration. Additional data from the site continues to be collected. Interfluve staff and project partners have been working iteratively to evolve the best possible restoration design. We anticipate presentations for public input and permitting submissions will take place in the winter of 2012-13.
Spring-Summer 2013: Project partners will seek funding for for project implementation.