Cold Brook

Bank Street Bogs Nature Preserve
Harwich, MA

The Harwich Conservation Trust (HCT) and Massachusetts Division of Ecological Restoration (DER) have partnered with the goal of implementing a comprehensive, process-based ecological restoration of the 66-acre Bank Street Bogs Nature Preserve, a former cranberry bog complex.  The project will focus on restoring the underlying ecological processes (i.e. natural movement and dynamics of water, sediment, nutrients, organic matter, light/heat and organisms) to transform the former bogs into a diverse, dynamic, and self-sustaining wetland and riverine habitat.  

This project became a DER Priority Project in 2011 and will benefit wildlife in areas designated by MA NHESP as BioMap Core Habitat and Critical Supporting Natural Landscape, provide enhanced ecological services, from floodwater storage and water purification to biodiversity maintenance and carbon sequestration, and create a vibrant landscape for public use and enjoyment.  

Cold Brook is located in an 822-acre watershed, originates in Paddocks Pond and is fed by Grass Pond. The lower portion of Cold Brook empties into Saquatucket Harbor.


On Wednesday March 5, DER along with an engineer with Stantec Consultants, members of the Town’s Engineering Department, and the Harwich Conservation Agent performed a site visit to the Carding Mill Dam on Cold Brook. The purpose of the meeting was to investigate opportunities to remove the dam to improve fish passage and river continuity as part of a larger restoration project being developed in the upstream watershed. However, upon inspection, it was quickly revealed that the dam’s collapse was imminent.

DER retained engineers at Stantec Consultants, Inc. to work with the town to develop designs and obtain approvals for an Emergency Certification for dam removal. Had the structure, a non-jurisdictional dam, been permitted to collapse in place, significant environmental damage and minor flooding would have resulted.  Working with the of Town of Harwich, DER provided assistance in securing permitting for dam removal and helped develop design plans and implement the removal.

Facing an approaching blizzard, the Harwich Department of Public Works worked quickly to remove the dam in a single day and ensured that the bank was stable to withstand storm flows. In the end, this dam removal project took only 20 days from initial site visit to removal. DER’s involvement facilitated the process and ensured the implementation of dam removal in an efficient and environmentally responsible manner.


Carding Mill Dam Before Removal      Carding Mill Dam After Removal  
Carding Mill Dam Before Removal After Removal of Carding Mill Dam