The costs to rebuild Montgomery Dam and maintain it over the next 50 years are estimated at $1.3 million. It would cost the same amount to remove the dam and open up fish passage by recreating a natural river channel through lower Harbor Park. Adding and maintaining fish passage to the Montgomery and upriver dams costs at least an additional million per dam. Grant funding is expected to lower lifetime costs for removal of Montgomery, Knox Mill and Knowlton Street dams and some fish passage options.
The wheel of history took a turn one evening in November 2017, when Select Board members expressed interest in alternatives to approving a bid to repair Montgomery Dam.
Illustration by Dan Kirchoff
Illustration by Dan Kirchoff
Four years later, Town Manager Audra Caler, with encouragement from board members, has brought in $190,000 from federal and state grants. These grants are intended to help towns prepare for impacts of climate change, such as increased rainfall and flooding in the Northeastern United States.
The grants were issued by the National Oceanic and Atmospheric Administration and other government agencies to support measures such as reducing flood risks, removing dams, encouraging fish passage and restoring rivers to a more natural state so they can handle rain events bringing more water.
Over the past four years, the majority of board members, including those newly elected, maintained interest in alternatives to repairing dams. The board used the grants help pay for studies conducted by Inter-Fluve on Camden’s dams on the Megunticook River.
The first study released in May 2019 focused on the Montgomery Dam and recommended its removal. The dam was built in 1771 and is the oldest of six remaining dams on the river in Camden, between Megunticook Lake and the harbor.
The dam is the last in the line before the river empties into the sea, and has been prized for its beauty and historic value by many residents and visitors.
In July 2019, Caler announced officials were considering removal of the privately owned Knowlton and Knox Mill dams and the town-owned Montgomery Dam, while preserving and maintaining the East, West and Seabright Dams.
At that time, several Main Street business owners questioned removing Montgomery Dam. Camden Deli owner Tom Rothwell made it clear he wanted to preserve the dam he called one of the town’s most beautiful, and most photographed features. Afterwards, the first “Save the Dam Falls” banners appeared on the back deck of Marriner’s Restaurant on Main Street.
Ron Hawkins, who captains tug boats, likens Montgomery Dam to an aesthetically pleasing water feature that airports and other places around the world spend hundreds of thousands of dollars to create.
“We have level ponds where water cascades evenly all around the perimeter,” he said. How it is that the Montgomery Dam doesn’t qualify as a water feature, and is only associated with its industrial roots? he asks.
Other residents welcomed the study’s recommendations to remove the dam to prevent flooding, encourage fish passage and benefit the environment.
Brian Robinson values the waterfall over Camden Harbor for its natural qualities. He is a partner with Evergreen Home Improvement, has worked in outdoor recreation and volunteers with the Parks and Recreation Committee.
“We are the only river in Maine that has a precipitous drop into the ocean. Every other river has some sort of tidal flow at the end. That does make Camden absolutely unique,” Robinson said. He likes to fish at Camden Harbor, and for him, the waterfall is the water flowing over the rocks and into the river.
Robinson sees dam removal as an opportunity to reclaim more of the natural landscape, including “the historical waterfall that has been there since the ice sheets retreated, until now,” he said. He also supports restoration of a historical river channel Inter-Fluve’s engineers believe flowed through the bottom of Harbor Park.
Stephanie Smith thinks the best course of action is to follow recommendations by the experts who understand hydrology and weather patterns to achieve a healthy river that doesn’t adversely impact the safety of our town.
Smith lives across from the river and supports, “whatever is going to result in a healthy ecosystem for our watershed,” including restoring “nature’s waterfall at the harbor,” and a “river as natural as it’s meant to be.” To achieve this “each dam has to be looked at individually,” she said.
She attends meetings and asks questions about the issues Camden is facing, and keeps track of other river restoration projects in Maine. In 2018, she initiated a citizen referendum vote to ban single-use plastic bags, approved by the majority of residents, which the Select Board opposed at the time. She has also sat on the other side of the table, as a school board member, where she learned “representing the public is not always easy.”
Since 2019, town officials have proceeded step-by-step with a plan to eventually hold a public vote on removal or partial removal of Montgomery Dam.
This summer, they sought public opinion during three virtual sessions on what the area where the dam is built should look like after the dam is removed. Supporters of dam removal, residents with questions, and supporters of preserving Montgomery Dam joined these conversations on Zoom.
Soon after the virtual sessions, citizen’s formed the “Save the Dam Falls” Committee and launched a campaign to preserve the dam.
“Save the Dam Falls” banners were hung from numerous downtown businesses. The committee is collecting signatures from residents to hold a citizen referendum vote on preservation and maintenance of the dam. It has urged the Select Board to hold more public meetings to discuss the dams and issues raised in the Inter-Fluve reports.
Supporters and opponents of dam removal appreciate different features of the falls over Camden Harbor. Those who have read the Inter-Fluve reports also view that information from different perspectives.
Roger Akeley was Director of the Lakes Region Commission in New Hampshire and commissioner of planning in upstate New York. He thinks there was an understanding early on between the town and grantor agency of what the proposal should be and what kind of consultant they should get to do it. “It was all tied up in a bow before the public had a chance to try to figure out what the issues might be in a resiliency setting,” he said.
This led to a report he thinks is good in many respects, but does not justify removal of the Montgomery Dam. He thinks more transparency and public involvement at the beginning, before Inter-Fluve was hired, could have led to a different set of alternatives.
“The Montgomery Dam is such a minor part of a huge project they are proposing and somehow that’s become the face of this project. It shouldn’t be,” Akeley said.
FLOODING IMPACTS
A central issue studied in both the 2019 and 2021 Inter-Fluve reports is the impact of Camden’s dams on flooding.
The Montgomery Dam is located between buildings on the east side of Main Street and the harbor. The river flows under numerous buildings on both sides of the Main Street bridge, then enters the impoundment pool behind the dam.
The impoundment, or pond, behind Montgomery Dam. Photo by Susan Mustapich
Where the water is high enough to fill the impoundment, it spills over the dam’s crest, which is two-feet thick and 100-feet across. Then it tumbles onto ledge and rock, where it splashes, sprays and churns into foam on its way to the harbor. The drop from dam crest to harbor is approximately 17 feet at high tide, according to the Inter-Fluve report.
The dam is built at an elevation of 24.5 feet when measured from high tide. Partial removal of the dam would lower its height to 20 feet above high tide. With full dam removal the riverbed elevation would be 13.4 feet, according to the report.
The 100-foot long stretch of the Montgomery Dam impoundment is drained, revealing deterioration of the crest of the dam. Voters had approved funds for repairs in 2017. Photo by Susan Mustapich
The report models impacts of the Montgomery Dam on water elevations within 10 feet upstream of the dam and 40 feet upstream of the Main Street bridge, during two types of high-water events, and on an ordinary summer day in June.
The models show water levels are highest within 10 feet of the existing dam, and predicts how much lower the water would be if the dam was removed or partially removed. However, the report does not provide information about water levels in the area of the buildings located behind the impoundment.
Within 10 feet upstream of the existing dam, models show water elevations, as measured from the high tide line in Camden Harbor, rising as follows: to 26.3 feet during a minor high-water event, 28.2 feet during a major high-water event, and 24.8 feet on an average day in June.
With partial dam removal, water elevations are estimated to measure 22.8 feet during the minor event, 25 feet in a major event and 20.6 feet in June.
With full dam removal, elevations are estimated to measure 17.5 feet during a minor event, 19.9 in a major event and 15.2 feet in June.
The Megunticook River flows under the Main Street bridge before reaching Montgomery Dam and Camden Harbor. Both the dam and the bridge have some impact on water levels 40 feet upstream of the bridge, according to the Inter-Fluve report. Photo by Susan Mustapich
Models show the Montgomery Dam also has an impact on water elevation 40 feet upstream of the Main Street bridge. At that location, the riverbed is between 19 and 20 feet above the high tide line in Camden Harbor, according to Inter-Fluve. During a major high water event, water elevation could measure 29 feet above high tide, 40 feet upstream of the bridge.
While the report does not provide information on water elevations more than 40 feet from the bridge, it does state the Montgomery Dam has no impact downstream of the Washington Street Bridge, and has negligible impact in the vicinity of the Brewster building.
The Montgomery and Knox Mill dams have no impact on water levels at the Brewster Building, which spans Mechanic Street to Tannery Lane. The building houses two businesses and is constructed over the Megunticook River. Photo by Susan Mustapich
Hawkins sees regulation of water level in Megunticook Lake as more significant to water elevations downstream than the downtown dams.
“We have one measure we can take to prevent a flooding event,” he said. “If we can just agree that Megunticook Lake is the only storage facility we have in a heavy rainfall event, then we have to focus on what level we’re going to keep the lake at in order to prepare for this event.”
After the summer recreation season, a decision needs to be made on what the lake level needs to be, he said.
He also has personal connection to dams. He once owned a dam and his father Havilah owned a small turbine that operated for a few years beneath what is now the “Once A Tree” store on Main Street. He believes knowledge of monitoring lake levels has been lost in the passing of Joe Sawyer [who rebuilt Seabright Dam], Ken Bailey and his father.
“There was no continuity in passing the baton to another generation, from those who clearly understood this watershed,” he said.
Hawkins also would like to see dramatic rainfall events redefined, not as 100-year-storms, a statistical figure based on prior rainfall, but “as the amount of rainfall we have in a four or six-hour period. Let’s look at these events, see how often they are happening and if we can identify a trend.”
Knox Mill and Knowlton Street dams
The Megunticook River Feasibility Report (May 2021) shows that each of the three downtown dams increase water levels directly upstream in major and minor high-water events. However, no dam has any effect on water levels downstream of another one of the dams.
None of the dams have any impact on flood water elevations around Washington Street, whether they remain or are removed, according to the report.
Removing the Knox Mill Dam would lower water levels behind the dam between 9 and 10 feet in 100-year, 10-year and 1-year high water events.
Removing the Knowlton Street dam would lower water levels behind the dam about 4 feet, and from 2 to 3 feet 125 feet upstream of the dam, in all three water level scenarios.
Dam removal and lowering flood water elevations in the vicinity of each dam, would produce “gains in flood buffering and storage in riparian or riverside areas, or by reducing water levels in nearby tributary drainages,” according to the May 2021 report. The location of the pump station at Rawson Avenue, west of the Knowlton Street dam, is one example of a tributary drainage area.
Removing the dams would increase “the space available for floodwaters within the river corridor” and maximize “ability to accommodate the uncertainty in changing climate,” according to the report.
However, dam removal is “unlikely to prevent all flood damage to buildings present along the river in downtown Camden. Buildings within the floodplain could adopt strategies to reduce the impact of severe or nuisance flooding in subsequent phases, such as floodproofing structures or elevating or relocating utilities.”
FISH PASSAGE
Based on consultation with Maine Department of Marine Resources, Inter-Fluve reports on the types of sea run fish that might reoccupy the Megunticook watershed following dam removal and/or fish passage construction. These fish include blueback herring (alewives), American eel, Atlantic salmon and rainbow smelt.
In 2018, Marine Resources suggested the potential for an alewife population of at least 300,000 fish based on the acreage of potential habitat in the watershed.
Simply removing the Montgomery Dam would not provide fish passage due to the limited ability of fish to swim up grades steeper than 3% to 5% for a sustained period of time, according to the report. Recommendations cover a wide range of fish passage options, and designs.
Montgomery Dam
For the three options of dam reconstruction, partial and full removal, a Denil fishway set within the existing falls area, alongside the sluiceway and Harbor Park wall can be used. The Denil is considered technical fish passage, and the least attractive and natural. It may require large pools for the fish to rest after swimming uphill, or a switchback arrangement to reduce the grade.
With partial dam removal, construction of a pool-and-weir fish passage structure is feasible both within the existing ledge area below falls or along an alternate alignment through Harbor Park, according to the report.
With full removal, a nature-like fishway may be possible along a route along the lower level of Harbor Park, that would follow what Inter-Fluve believes is the original path of the Megunticook River.
Robinson supports the recommendation to encourage fish passage along the restored river channel through the park.
“We can enhance the experience for ourselves as a community, as well as for tourists,” he said. Thinking about being on the grounds of the library, on the public landing or out on a dock, he imagines “the draw of a half million fish fighting their way up stream would be incredible.”
Inter-Fluve calculates the 50-year lifespan costs for various fish passage options, which includes annual operation and maintenance, and a 3% rate of inflation. Costs of numerous Montgomery Dam fish passage options range from $2.1 million for Denil fishways with full dam reconstruction to $1.3 million with dam removal and fish passage along a natural route through the park. The 50-year cost of full dam reconstruction with no fish passage is also estimated at $1.3 million.
Rothwell thinks many factors covered in the Inter-Fluve reports “can be addressed without the removal of Montgomery Dam, which town officials are currently focused on dismantling. We can have fish passage without removing the dam, which preserves local history and benefits the environment.”
Knox Mill, Knowlton Street, Seabright, East and West dams
The Knox Mill, a privately owned dam, is considered to be a major impediment to fish passage up the river if not removed, according to the report.
Fish passage without dam removal is difficult to achieve due to the dam’s steep incline and narrow width, according to the report. A Denil fish ladder could be placed in the vicinity of the dam’s spillway, but this is not recommended because it may increase flooding problems for adjacent buildings.
The 50-year life-span cost estimated for removing the Knox Mill dam, minus anticipated grant funding, totals $380,000. The cost of the Denil fishway considered less likely to receive grant funding is estimated to be $840,000.
The Knox Mill dam is considered to be an impediment to fish passage unless removed. Photo by Susan Mustapich
If the Knowlton Street dam is not removed, a pool-and-weir fishway is recommended. If the dam is removed, fish passage may be possible without constructing fishways, according to the report. The Knowlton dam is also privately owned.
Removal of the Knowlton dam includes restoration of the impoundment area, which extends 2,800 feet upstream. It involves excavation of accumulated sediment found to cover the bed of the impoundment at a thickness of 8-10 feet. This area has the potential for renaturalization that can contribute to improved water quality and wildlife habitat, according to the report. While increased floodplain storage and flood reduction is assumed, the extent has not yet been determined.
Removing the sediment behind the Knowlton Street dam increases dam removal construction costs to between $3.3 and $5 million, according to the report. Due to anticipated high potential for grant funding, the overall 50-year lifetime costs are estimated to be $380,000.
Nature-like and pool-and-weir fishways are recommended for Seabright Dam and for East and West dams.
Lifetime costs for a nature-like fishway at Seabright are around $580,000, due to higher likelihood of grant funding. Lifetime costs for pool-and-weir fishways, less likely to receive grant funding, are estimated to be $1.2 million for each of the three dams.
SEDIMENT
Residents raised concerns about contaminated sediment accumulated behind the dams after hearing dams were being considered for removal. The following amounts of sediment are estimated to be located behind each of the three downtown dams: Montgomery Dam, 250-300 cubic yards; Knox Mill, 200 cubic yards; Knowlton Street, 27,500 cubic yards.
The 2021 Inter-Fluve report contains detailed data on chemical analysis of sediment samples taken from behind each dam. Overall, the report concludes chemicals in sediment behind the dam, including semi-volatile organic compounds and concentrations of metals, are similar to what is found in sediment at the bottom of the harbor. Sediment would be removed prior to dam removal, according to Inter-Fluve.
THE FUTURE
Select Board vice-chair Alison McKellar initiated the discussion in December 2017 on environmental impacts of dams and removing dams to restore fish passage.
Looking forward, McKellar hopes “in 50-100 years people will look back and be proud of the way that Camden responded to this moment in the history of the Megunticook River Watershed. I hope a walk through downtown Camden will leave people informed and with a sense of the incredible engineering that went into harnessing the river’s power when it was needed by the first settlers, as well as the magic and beauty of the natural evolution that engineered the river’s channel over thousands of years before us.”
“It may take 100 years but someday I hope we can kayak from Norton Pond all the way to downtown Camden and that fish like brook trout and alewives can have a chance at fighting up the natural falls in downtown Camden going the other direction,” she said.
Akeley and others with “Save the Dam Falls” Committee believe Montgomery Dam can be preserved because of its lack of impact on flooding. Their vision focuses on repair of the dam to improve its appearance. The “aesthetics and beauty attract tourism, which is an economic benefit,” Rothwell said.
The dam is right where the fresh water meets the sea, in the center of downtown Camden, next to the beautiful park and library, Akeley said. “It’s also a historic wonder. It doesn’t get better than that.”
Robinson sees the community “at an inflection point, a fork in the road,” which is something that comes around “maybe once in a lifetime.” To him, this means looking 75 years into the future, and asking “what would we like to see?”
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