ACUSHNET RIVER FISH PASSAGE
National Oceanic and Atmospheric Administration
The Acushnet River is a perennial stream located in southeastern Massachusetts. The Acushnet River has its headwaters in the Town of Freetown, and flows generally southward through the Towns of Acushnet, New Bedford, and Fairhaven, Massachusetts to discharge into New Bedford Harbor. The river drains a watershed of approximately 15 mi2. Land use within the watershed is predominantly urban and suburban land. Historically, the Acushnet River was used as an industrial waterway during the 18th and early 19th centuries. Dams were constructed along the river to provide hydropower for numerous mills. These dams impaired the function of the Acushnet River to serve as habitat for resident aquatic life and as a conduit for a variety of seasonally-transient aquatic life, including anadromous fish such as river herring.
At present, the lowest 4.4 mi of the 8.2-mi Acushnet River system is tidally influenced estuarine and riverine habitat with no significant impediments to anadromous fish passage. The first obstruction along the river is the Sawmill Dam, an earth-fill dam with a 118-ft wide concrete and stone spillway approximately 4.6 ft high. The Hamlin Street Dam, located 0.9 mi north of the Sawmill Dam, is a public roadway over a former mill dam which passes the Acushnet River through three granite block culverts. At the head of the Acushnet River system, the New Bedford Reservoir provides 220 acres of underutilized spawning habitat. An 11-ft high dam at the reservoir outlet formerly posed a third obstruction to fish passage along the river; however, in 2002, a state-of-the-art Denil fishway was installed at the outlet from the New Bedford Reservoir.
The Acushnet River fish passage restoration project has re-established river continuity by improving fish passage from Sawmill Dam up to the New Bedford Reservoir. Fish passage has been restored by a combination of channel alterations, bank reconstruction/stabilization, and modification of the Sawmill and Hamlin Street dams. Engineering design was completed and engineering plans were prepared along with required state and federal permit applications and filings. Upon receipt of applicable state and federal permits, final engineering plans and construction specifications were prepared. National Oceanic and Atmospheric Administration solicited construction bids in March 2007, and the contract for construction was in place by June 2007. Construction of the planned improvements was initiated in July 2007 with acceptance of final project completion in September 2008.