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Removing barriers and returning life to a New England stream

Removing Barriers & Returning Life to a New England Stream







Partner agencies collaborate to restore aquatic connectivity through Central Maine project

By Thomas Kielbasa
Public Affairs Specialist
Natural Resource Conservation Service-Maine

VASSALBORO, Maine (Dec. 10, 2020) – In the distant past the small winding stream in Central Maine would have been noticeably alive.

A solitary duck swims along the channel of the China Lake Outlet Stream in Vassalboro, Maine. The project to remove or circumvent barriers along the seven-mile waterway will help improve the stream's health for many species, including fish and waterfowl. Photo by Thomas Kielbasa, NRCS-MaineIndigenous people would have camped along its leaf-strewn banks and fished its depths, while fauna crept and glided through the babbling shallows in search of slower prey. Seasons and weather would guide life along this aquatic passage that helped drain water away from a medium-sized lake into a major river – a roughly seven-mile course of life that snaked like an eel through the Kennebec River Basin.

Its waters would ultimately pour into the Gulf of Maine, serving as part of a primeval superhighway for aquatic life from Maine’s inland forests to the northern Atlantic and beyond.

Any glimpse into that deep past is a guess at best, but what we do know is that by the mid-18th and 19th centuries dams and mills had sprung up along the banks of this stream. This industrial age in northern New England placed artificial barriers along the China Lake Outlet Stream and for nearly three centuries disrupted natural movement of species including eels and alewives.

Today a balance between the natural environment, legacy land use, and the current needs of the Outlet Stream is being struck.

The Project

A group of partners and agencies led by “Maine Rivers” has been working with the community of Vassalboro on solutions to fish passage along the China Lake Outlet Stream. The hoped-for outcome of the “China Lake Alewife Restoration Initiative” will be to reconnect the nearly 4,000-acre China Lake in Vassalboro to the Sebasticook and Kennebec Rivers, which flow into the Atlantic in Southern Maine.

Fish passage at the Lombard Dam on the China Lake Outlet Stream was hindered in 2015 (left) but the stream was flowing smoothly in 2020 after the dam was removed. Photos by Thomas Kielbasa, NRCS-MaineAccording to Alewife Restoration Initiative Project Manager for Maine Rivers Matt Streeter, the $3.25 million project focuses on either removing or by-passing six aging dams on the Outlet Stream. The project partners have already invested significant financial and technical expertise over the past decade to completely remove two dams, construct “fishways” alongside two more, and are planning for construction at the last two sites.

Streeter estimated that the entire project should be completed by late 2022.

“In the case of the three dam removals that are part of the project, there will be a restoration of stream-habitat to long-impounded reaches of the Outlet Stream,” Streeter explained. “The first two miles of Outlet Stream below the lake will be free flowing, where it was previously more or less completely impounded. This improves oxygen levels, lowers stream temperature, improves sediment and woody material transport, and reduces habitat for invasive fish and plant species.”

As the barriers are removed, the stream banks and adjoining riparian buffers are restored with a variety of native plants; this helps improve the number and diversity of insects, amphibians, reptiles, birds, and small mammals living in those buffer areas.

This ambitious project is also seen as a valuable opportunity to help resolve water quality problems in China Lake itself: once juvenile alewives are present in the lake they can ingest phosphorus (that has come into the lake as runoff) and take it with them when they migrate unobstructed out to the Atlantic in late summer. This decrease in phosphorus levels will in turn help decrease algae and cyanobacteria in the lake, which can spread throughout the lake if left unchecked.

The Partners

In addition to Maine Rivers, this project has impressive representation from several local groups, and state and federal agencies. They include: Sebasticook Regional Land Trust; China Region Lakes Alliance; China Lake Association; Maine Department of Marine Resources; The Nature Conservancy in Maine; the U.S. Fish and Wildlife Service; and the USDA’s Natural Resources Conservation Service (NRCS).NRCS-Maine State Conservationist Matt Walker (left) receives a briefing on the status of an Aquatic Organism Passage project in Vassalboro, Maine, from Agricultural Engineer Heidi Bunn, on Oct. 27, 2020. Photo by Thomas Kielbasa, NRCS-Maine.

While each group has different methods to improving conservation and ecological balance in Central Maine, a large project like the “China Lake Alewife Restoration Initiative” requires a broad collaborative effort with many experts and funding streams.

“These projects would not be possible without bringing together partners that are representing all of the important ecological, economic, and recreational benefits,” The Nature Conservancy Watershed Restoration Specialist Eileen Bader Hall said. “The Nature Conservancy is primarily thinking about ecological outcomes, but that has to be aligned with fitting into the needs of the local communities.”

The USDA’s NRCS – which is focused on addressing natural resources concerns in the watershed through its Regional Conservation Partnership Program (RCPP) – has provided a mix of financial and technical assistance towards completion of the project, including $450,000 in financial assistance alone at two of the sites.Maine Department of Marine Resources Biologist Nate Gray (left) and Nature Conservancy Watershed Restoration Specialist Eileen Bader Hall inspect the construction of site of the fish passage at the Box Mill Dam in Vassalboro, Maine, in late October 2020. Photo by Thomas Kielbasa, NRCS-Maine

“Even though we might not be involved financially in every dam removal or bypass, we are at the table providing technical assistance to address all of the issues,” NRCS District Conservationist Peter Abello noted during a late October visit to one of the project sites in North Vassalboro.

He pointed out that NRCS biologists and engineers have been active in the design process at each of the sites on the Outlet stream, and the current state of the project is a testament to “how beneficial these multi-agency partnerships” can be for preserving the delicate ecology of Maine’s lakes and streams.

“One of the priorities of NRCS is to conserve Maine’s precious natural resources for future generations,” Abello explained. “That means making sure our water and soil quality, as well as wildlife health, is preserved. By adding our technical talents and fiscal resources to projects like this on the China Lake Outlet Stream, we meet those goals. But it is really the partnership component of projects like this that make our efforts successful.

“When this project is completed in a few years, and the alewives and other fish are moving freely upstream into China Lake, the success will be due to the many talented and committed partners that helped make this a reality,” Abello added.

The Alewives

According to Maine Department of Marine Resources Biologist Nate Gray, this restoration effort could significantly increase the river herring population, which includes the alewife fish, in what is already “one of the largest populations of river herring in the world.”

“When we started working with these fish species in the greater Kennebec Basin, we were lucky to be able to scratch together 100,000 fish in a season,” Gray explained. “Now we are looking at population estimates somewhere between three and five million just on the Sebasticook River alone. At its culmination, this project should produce somewhere in the order of 750,000 to 1.25 million additional river herring annually.” Alewives swim in a Central Maine stream during the Spring spawning season in this frame captured from a GoPro video. This recent Alewife Restoration Initiative hopes to reintroduce free fish passage to nearly seven miles of the China Lake Outlet Stream. NRCS file image

Alewives are anadromous species – meaning they migrate up the rivers from the ocean to spawn – and when they reach their spawning grounds they feed on plankton and in turn help control rampant algae in Maine’s lakes. With passage upstream blocked by dams, the fish cannot reach those spawning grounds easily.

Gray noted that the stream restoration and alewife return will bring immeasurable ecological benefits for other species like the American eel, other migratory fish, minks, otters, and even seals and bald eagles.

“It has amazing depth and breadth of impact to the local ecosystem and surrounding areas,” he explained of the project.  “(The Kennebec River Basin) is home to one of the largest naturally occurring aggregations of eagles east of the Mississippi. We see up to 85-95 bald eagles all in the same area feeding on the same resources.”

But eagles and alewives aside, the project also has positive impacts for the community of more than 8,000 human residents in the towns of Vassalboro and China. 

The Community

Two of the most visible portions of the project lie nearly three miles downstream from China Lake, inside the village of North Vassalboro. The two picturesque dams – the Box Mill and the Ladd Dam – were left in place at property owner Raymond Breton’s request, and fishways were constructed alongside the stream to provide upstream passage for the fish.

A newly constructed artificial channel at the Ladd Dam in Vassalboro, Maine, is one of the “China Lake Alewife Restoration Initiative” projects designed to facilitate the passage of alewife fish during spawning season. Photo by Thomas Kielbasa, NRCS-Maine“This is beautiful….It was a lot of work and it blends in with everything around it,” Breton said during a site inspection of the Box Mill dam site with project partners in late October. As Breton walked the streambank, he pointed to the new artificial channel running alongside the waterfall left at the remains of the dilapidated dam; removable barriers, called baffles, were constructed in the fishway to help control the water and give fish a place to rest as they fight the current on their way to spawn in the Spring.

The stream at the Box Mill site runs alongside an imposing brick building – a former textile mill from the 1850s – which Breton currently rents out for businesses, warehouse space, and special events like weddings. Breton asked that the new fishway’s design include a new sidewalk, railings and viewing spots so that visitors could enjoy the spot and watch the fish move upstream.

Breton noted that a lot of people have already visited the site to view the stream modifications, and have already seen a variety of fish, eagles, and even a mink who swims in the pool above the cascades.

“You have the old original dam with the stonework from 1850, and when you go down to the end and look at it all it blends in,” Breton said. “This is the new meeting the old. It is a beautiful piece of work…I’d say I was the luckiest guy in this town to have a piece of property that is this beautiful.”

Biologist Nate Gray noted that the projects at both the Box Mill and nearby Ladd Dam are unique in that they will be very visible to the general public. And although the term “pretty” doesn’t usually come to mind when describing a fish passage, Gray said the project was something that “that Martha Stewart would be proud of.”

“Making a fishway publicly accessible isn’t the norm,” Gray explained. “A lot of work went into this project at what is a post-industrial age site. A lot of people are going to come here, and they will get a much better idea of the impact of these restorations. They will see be able to see the fish pass through this site on their way to their spawning grounds on China Lake.”

Updates on the project can be found at and