Case Study

Damariscotta Fish Ladder

Challenges

The original fish ladder was a series of small pools connected by short passages that raised over 42 feet from the bay to the impoundment. The fish ladder worked well for about 180 years but its stonework and the underlying concrete deteriorated as ice dislodged stones and blocked the path for the fish. By the 1990s, the fish ladder was in very poor condition, and fish count plummeted to less than 200,000.

Solutions

With strong community organizing, and fundraising, the reconstruction of the fish ladder began in 2007. The redesign and reconstruction of the fish ladder is similar to that of the original, consisting of a series of 69 ascending pools connected by weirs, or short waterfall passageways that each rise 8-10 inches. The reconstruction took over 10 years and could only take place from November - April to avoid spawning season. In April every year, the construction team had to stop so the ladder could be used for the spring migration. The renovated ladder winds 1,500 feet up the hill and was reconstructed using the original stones and designed to weave around mature trees that shade the pools.

The lower pools are publicly accessible and include a boardwalk and signage. The upper portions snake through residential backyards before reaching the lake.

At the lower end of the pools, a set of “dippers” and troughs, allow for the towns to harvest alewife. The harvested alewives are used primarily as lobster bait however a few bushels are smoked and sold for human consumption. All funds received for harvested alewives are spent to maintain and restore the fish ladder and harvesting area.

Successes

Following the restoration, more than one million alewives pass up the fish ladder to spawn each spring making the Damariscotta river one of Maine’s oldest and most productive alewife fisheries.
Community support has been key to the restoration of the fish ladders. An annual Herring festival took place from 2007 until the pandemic and helped raise funds and support for the restoration. Currently the community group is raising funds to replace the boardwalk and foot bridges . Volunteers are present at the Fish Ladder on May weekends to welcome visitors, and sell tee shirts caps and other Fish Ladder. In addition, fundraising takes place at community events such as a silent auctions, an annual “Alewife run” and concerts.

Plans of the fish ladder before and after restoration.

References and Additional Resources

https://damariscottamills.org/

https://www.atlasobscura.com/articles/fish-ladder-maine-lobster-industry

Location
Nobleboro, Maine
River
Damariscotta River
Year
Originally constructed in 1807 and then restored and rebuilt and restored between 2007-2017
Type
Pool and Weir Fishway
Cost
Restoration cost over $1,000,000
Project Partners
Towns of Nobleboro and Newcastle, the Nobleboro Historical Society, US Fish and Wildlife Service, Maine Department of Marine Resources, and the involvement of many community members

The Dam Atlas is a guide for communities to understand, evaluate, and make decisions about historic dams.

New England is home to more than 14,000 dams, many of which are small, “legacy” structures built over a century ago. Most no longer serve their original industrial purposes and are reaching the end of their useful lives, raising concerns about safety, maintenance, and ecological impacts. These aging dams can threaten downstream communities, especially as climate change brings more frequent and intense storms. While dam removal is often advocated for ecological, economic, and safety reasons—such as restoring fish passage, water quality, and sediment flow—many communities feel a strong attachment to their local dams. Dams and their impoundments have become part of the landscape, local history, and sense of place, sometimes even serving as town landmarks or symbols of cultural identity.

The goal of this website is to share this work and support communities who are making decisions about the future of a dam. Decisions about dams are inherently complex and require the consideration of ecological, social, safety, and economic trade-offs. While there are many great resources and publications for proponents of dam removal, this website aims to provide an unbiased source of information on the ecological and social considerations associated with dam decisions. Rather than advocating solely for removal, the goal of this approach is to bring a community into an open conversation to think creatively about the future of a dam. While this may seem counterintuitive if your role is to advocate for dam removal, engaging communities in an open but structured discussion about the future of a dam has the potential to lead to better environmental outcomes and a community that has more ownership, connection, and sense of stewardship over their river. In addition, this approach has the potential to address what are often perceived as unequal power dynamics between dam removal proponents and the local community, which has led to projects stalling or failing in the past.

This website consists of four main sections: The first chapter, “Understanding Dams,” introduces key ecological, social, infrastructural, and economic factors that are important to consider for the management of dams at the individual and watershed scale. The second part, “Scenarios & Case Studies,” looks at various alternatives for the future of a dam and presents a series of case studies of projects throughout the region. The third chapter, “Making Decisions,” shares methods, ideas, and tools for how to engage in conversations about the future of a dam. The last section, the Interactive Dam Atlas, was developed in collaboration with faculty from the University of Rhode Island and helps to visualize and build a geographic understanding of dams in the Narragansett Bay and Rhode Island coastal watersheds.

While this Dam Atlas is focused on dams in the Narragansett Bay and coastal watersheds of Rhode Island, the metrics calculated in the GIS analysis can be applied to other watersheds, and the decision-making tools are not region-specific. By sharing our methods and the open-source decision support toolkit, the aim is to help support practitioners and communities that are looking for ideas, methods, and techniques for having discussions about the future of a dam. We encourage others to use, test, modify, evolve, and share these methods. Ultimately, the goal is for this work to contribute to a “library of approaches” that are openly shared to build knowledge and techniques to support collaborative environmental decision-making around dams.