Case Study:  Gilbert Stewart Dam

Location: North Kingstown, RI
River: Gilbert Stuart Stream / Narrow River
Goal: Fish passage
Type: Alaskan steeppass fishway
Cost: unknown (fish ladder), $54,000 (picket weir)
Dam Owner:  Gilbert Stuart Birthplace & Museum
Year: 1960’s (fish ladder), 2021 (picket weir)

Primary Partners: Gilbert Stuart Birthplace & Museum, Rhode Island Division of Fish and Wildlife (1960’s fish ladder) The Nature Conservancy, the RI Department of Environmental Management (DEM), Horace and Ella Kimball Foundation, Narragansett Improvement and Preservation Foundation, Rhode Island Saltwater Anglers (picket weir).

Context: Gilbert Stuart Stream is the largest freshwater tributary to the Narrow River, which empties into the Narragansett Bay. For over a century, a small dam located at the historic home of artist Gilbert Stuart has impeded the passage of migratory river herring, who travel up the Narrow River via Gilbert Stuart Stream and into Carrs Pond to spawn. In the 1960’s, Rhode Island’s Division of Fish and Wildlife installed an Alaskan steeppass  fish ladder that allowed thousands of migrating river herring to pass to Carrs Pond.

Challenges: Although the 1960’s fish ladder allowed herring to pass to Carrs Pond above the dam, a junction that led to a mill race frequently attracted and confused the fish, forcing them to choose the wrong path. If the herring turned into the mill run instead of the fishway, they were prone to becoming trapped and ultimately dying.

Solutions: The Gilbert Stuart Museum was able to maintain the character of the historic dam by implementing a barrier that would allow water, but not fish, to pass through the mill run. The blocking structure, known as a picket weir, resembles a picket fence and is aesthetically consistent with the historic character of the surrounding property. This picket weir is a novel alternative to the Department of Environmental Management’s practice of using temporary plastic fencing, which can be visually distracting and prone to failure during high flow.

Successes: In recent years, between 30,000 and 100,000 herring may be seen migrating up the Gilbert Stuart fish ladder. The Gilbert Stuart Birthplace & Museum hosts an annual spring fair, where visitors are encouraged to watch the herring run from trails and bridges, as well as via an underwater camera stream. The Shady Lea Mill dam, situated above Carrs Pond on the Mattatuxet River, was designated as a “high hazard” and was removed in 2018. This subsequent project opened an additional ½ mile of river to the herring, eels, and trout.

Case Study: Oliver Mills (Muttock) Dam

Location: Middleborough, MA
River: Nemasket River
Goal: Migratory fish passage
Type: Pool and Weir Fishway
Owner: unknown
Cost: unknown
Year: 1982

Primary Partners: Massachusetts Division of Marine Fisheries. 

Context: The Nemasket River supports the largest and longest herring run in Massachusetts. The herring make the yearly 40-mile journey from Mount Hope Bay through the Taunton and Nemasket River to the  Assawompset Pond Complex to spawn. Members of the Wampanoag  Tribe built weirs to catch migrating herring each spring in a village at Muttock (now Oliver Mills area).  In 1734, the weirs were replaced by a dam, which was used to power iron works, grist, and saw mills serving the colony of Middleborough until it was abandoned in the 1870s. Throughout this period, the site remained an active fish run, with highly organized yearly efforts to catch and distribute the passing herring, which were cooked and distributed at the nearby community herring house. The Oliver Mills dam is the first of three dams on the Nemasket River between the undammed Wild and Scenic Taunton river and the valuable spawning grounds of the Assawompset Pond Complex.

Challenges: The mill and dam remained in a state of abandonment until the 1960’s, when Oliver Mill Park was opened surrounding the dam and historic industrial ruins. Herring populations in the Nemasket River declined dramatically during this time, with a mysterious die-off event in 1965. Low water levels and invasive plants exacerbated the issue and prompted proposals to reestablish fish passage on the river. 

Solutions: The fishways at Oliver Mill were initiated by an effort to restore the ecological and cultural heritage of the Nemasket River. During the 1960’s and 1970’s the site was partially restored for recreation, fish passage,  and to preserve the industrial archeological site. During this time, two stone fish ways were installed. In 1982, the Massachusetts Division of Marine Fisheries built a new stone and concrete notched weir-pool  fishway. In 1996 the Middleborough-Lakeville Herring Fishery Commission was created to administer and enforce herring harvest regulations, maintain and enhance herring habitat, and public education on the herring run. 

Successes + Lessons Learned: The Nemasket River is relatively short (11.2 miles) with only 3 dams between the ocean and the 1,721 acres of prime spawning grounds of the Assawompset Ponds. Taking a whole river approach, fishways have been constructed at all three dams, allowing fish passage into the ponds. In 2013, almost one million herring were able to pass through the fishway at Oliver Mill to spawn in Assawompset Pond! 

The communities of Middleborough and Lakeville have been shaped by the abundance of herring in the Nemasket River. In addition to the ecological value of the annual hearing run, it is also an important social and cultural event. Community support to preserve the yearly fish run helped to spur the restoration of the river and the fish migration. Since 2013, local and state Cultural Councils and the Middleborough Tourism Committee have hosted the Annual Herring Run festival to bring the community together to celebrate the fishrun. These celebrations help to reinforce the relationship between the community and the herring, ensuring the herring remain an important part of the local identity and helping to spur continued stewardship and involvement in preserving and improving the annual fish runs. 

This case study is also an example of how a fishway can be integrated into a public park to achieve multiple objectives. With the creation of the Oliver Mill Park, the project was able to achieve the shared goals of improving fish passage, providing recreation, and preserving history. The fishways are integrated into the design of the park allowing the fishruns to be highly visible. Oliver Mill park provides paths for visitors to see the historic stone mill ruins and bridges that cross the multiple river channels and allow visitors to see the herring run below.  In 2000, Oliver Mill Park was listed on the National Register of Historic Places as the Muttock Historic and Archeological District.