Friday, April 2, 2010
Benfield to Bisbee Land trail linkage explored
The Conservation Commission (ConsCom) has voiced its enthusiastic support for a boardwalk and trails that would link the Benfield and Bisbee Conservation Lands. Steve Hinton of the non-profit Carlisle Conservation Foundation (CCF) and Steve Tobin from the town’s Trails Committee presented the concept at the March 18 ConsCom meeting. They have been investigating the feasibility of the project, which is part of a larger vision for connecting conservation parcels in the western part of Carlisle and adjacent towns.
The boardwalk would begin at the southeast corner of the Benfield Conservation Land off South Street, cross Spencer Brook and extensive wetlands, enter the Bisbee Conservation Land and link to a trail at the end of Hartwell Road off Concord Street (see map). The boardwalk would be just under 500 feet long and include a 25-foot raised section or bridge across Spencer Brook.
Hinton reported that the technology being explored to support the wooden boardwalk is a series of galvanized steel helical piers. If the boardwalk were to be commercially constructed, Solid Earth Technologies of Amherst, New Hampshire estimates a cost of about $30,000 for the piers – including installation. These would extend about three feet into the substrate – through the organic soil to the clay beneath. According to the firm’s website, helical piers have one to four plates, which resemble one pitch of a screw thread, and act like an auger, driving or turning the pier into the ground. The plates are welded onto a shaft, in this case a two-inch diameter pipe.
CCF’s vision, described by Hinton subsequent to the meeting, is to connect much of the west corridor of Carlisle with the Estabrook Woods, 400 acres of Acton Conservation land near the Spencer Brook Reservation, and the Bruce Freeman Rail Trail, which passes through Carlisle near the intersection of Routes 27 and 225. The Trails Committee and other groups helped develop the idea. These linkages would take coordinated effort from all of these conservation groups, as well as the Land Stewardship Committee.
As a first step to creating this extended trail system, CCF recommends that the town establish a trail from the parking area for the Benfield Conservation Land to a wildlife-viewing platform that would overlook Spencer Brook. This trail would connect with others proposed on the Benfield parcel. (See map. Note that exact locations of proposed trails will be determined after the location of the well for the affordable housing on the front portion of the Benfield parcel is finalized.)
CCF envisions simultaneously extending the trail that runs from the Bisbee Land to the Hartwell Road trail easement out to a wildlife-viewing platform, which will look across Spencer Brook to Benfield Conservation Land. The connecting boardwalk could be constructed at the same time if funding allows.
Land Stewardship Committee member Warren Lyman strongly supported the project, pointing out that the trails and boardwalk would meet a goal of the Town’s Open Space and Recreation Plan – to create linkages between public parcels. ∆
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