Weston Mill Dam Removed from Millstone River

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Weston Mill Dam in August 2017 just days before its removal.

The Department of Environmental Protection – in cooperation with the U.S. Fish and Wildlife Service, National Oceanic and Atmospheric Administration, Stony Brook-Millstone Watershed Association and other partners – is removing the obsolete Weston Mill Dam on the Millstone River between Manville and Franklin Township.

The removal of the Weston Mill Dam, also known as the Weston Causeway Dam, is the latest in a series of dam-removal projects undertaken by state, federal, nonprofit, and private partners to make waterways in the Raritan River Basin free-flowing again.

The project opens a 4.5-mile stretch of the Millstone River upstream of the dam to species such as American shad and river herring that spend much of their lives in the ocean and estuaries but need to return to freshwater rivers and streams to spawn. American eel, which spawn in the ocean but spend much of their lives in rivers and streams, will also benefit.

Funding for the project was secured by the DEP’s Office of Natural Resource Restoration, the National Oceanic and Atmospheric Administration, and the U.S. Department of the Interior through a Natural Resource Damage Assessment settlement agreement. It is occurring in an area purchased by the DEP’s Green Acres Program as an addition to the Delaware & Raritan Canal State Park as well as for the purposes of removing the dam.

Structures such as the Weston Mill Dam, which is 5.5-feet high, are known as low-head dams. These small dams were built many decades and even centuries ago to power mills, generate electricity and create lake-like sections of impounded water.  However, they have long prevented migratory fish from accessing important spawning habitats. As early as the late 1700s, it was reported that construction of dams and overfishing were causing the shad population in the Millstone River to decline rapidly.

Low-head dams create stagnant stretches of rivers that can be low in dissolved oxygen that aquatic life needs, while exacerbating excessive algae growth that can diminish recreational and scenic enjoyment. In addition, kayakers and canoers who are not aware of the dams can find themselves trapped in a vortex of roiling water should they accidentally tumble over them.The original dam at Weston Mill was built around 1844. The current concrete dam at the same location was built in the mid-1930s.

After the 112-foot-wide dam is removed, the river channel will be restored. Studies are underway to assess benefits to fish and improvements in the river’s overall ecological health.

The Weston Dam project is being conducted by Wyeth Holdings LLC under the terms of a Natural Resource Damage settlement agreement with the DEP, the U.S. Department of Interior’s Fish and Wildlife Service, and the U.S. Department of Commerce’s National Oceanic and Atmospheric Administration.

This agreement calls for Wyeth to implement the project to compensate the public for natural resource injury resulting from past pollution to the Raritan River from the American Cyanamid Superfund site in Bridgewater Township. Wyeth inherited responsibility for the American Cyanamid site through corporate successorship.

Other partners in the Raritan Basin effort include American Rivers, Conservation Resources Inc., the Geraldine R. Dodge Foundation, the Horizon Foundation and the Raritan River Fish Passage Initiative.

For a copy of the NRD settlement and the complete Restoration Plan and Environmental Assessment, visit: https://casedocuments.darrp.noaa.gov/northeast/am_cyanamid/admin.html

Article excerpted from August 10 NJDEP News Release.  Click here to read the full article.

See video of historic dam at the site:  http://raritan.rutgers.edu/video-westonmill-historic-artifacts/