Abandoned Dams

During the summer of 2001, Riverkeeper obtained funding to hire a staff member (Charles LeGresley) to research and produce two detailed reports, a web site section and an educational poster dedicated to the issue of abandoned dams in the watershed. The first report entitled “Reclaiming Free Flow – An Information Guide on Removing Small Abandoned Dams” was an 80-page step-by-step guide aimed at assessing the decommissioning of abandoned dams in the Inner Bay of Fundy. The second report entitled “Assessment on Decommissioning the Abandoned Humphreys Brook Dam” was a 65-page report on the feasibility of removing this abandoned dam located in Moncton.

Public consultations were held on these findings and the recommendation made to proceed with a detailed assessment for this project. One thousand copies of the educational poster were printed and distributed to schools and community groups throughout the watershed. The project triggered the creation of the Humphreys dam removal project, which was ultimately implemented during the summer of 2013 and the Mill Creek fish passage restoration project (Riverview, still outstanding).

Abandoned Dams Educational Poster (lien à l’affiche)

Reclaiming Free Flow – An Information Guide on Removing Small Abandoned Dams (lien au rapport)
Assessment on Decommissioning Humphreys Brook Dam (lien au rapport)
Back Brook
Humphreys Brook
Mill Creek

 

Back Brook

Description

Dam-Back-brook

- Dimensions of structure: 3.2 metres high by 25.8 metres long- Drainage area: Approximately 5 km2.The Back Brook dam removal project was the first project of this type to be initiated in the Petitcodiac River/Shepody Bay Watershed. Dam removal was carried out in August 2002 by Public Works and Government Services Canada and funded by Correctional Services Canada. This small dam was located on Back Brook, a small tributary of the Memramcook River, in a rural area near the Village of Dorchester. Built in 1930, the dam’s purpose was to create a potable water reservoir for the Federal Penitentiary at Dorchester. However, massive sediment build-up over the years in the headpond rendered the reservoir useless. In fact, the volume of sediment was such that it completely infilled the pond in the area adjacent to the dam, reaching to the top of the structure.

The decision to have the dam removed came as a result of various elements. First, the structure had become obsolete with the reservoir not serving its purpose anymore. Second, the dam had no built-in fishway which meant that fish passage upstream of the structure was impossible. Although the dam could have been left in place as it was still in relatively good condition, building a fishway (the existing configuration of the dam, if not altered, would have been considered a contravention of the Fisheries Act) and future maintenance would have proved as expensive as removing the dam.

Finally, environmental concerns expressed by local environmental groups such as Fort Folly First Nation who had had been carrying-out restoration work on Back Brook for some time acted as a trigger for the decision to have this small dam removed.

Humphreys Brook

Description

humphrey-brook

Humphreys Brook, situated in eastern Moncton, is an approximately 38 km2 sub-watershed, which is part of the larger Petitcodiac River catchment basin (2071 km2). A 4.7 metre-high, 9.1 metre-long dam built at the turn of the past century to generate power for the Humphreys Mill, sat idle just above the head of tide for over half a century (underneath the old Mill Road Bridge in Moncton).The area is historically important to the Mi’gmaq; oral tradition speaks of a native camp situated at the head of tide on Humphreys Brook, which would suggest that the stream did at some point provide an important source of food fishery to the Mi’gmaq. The dam in question served no economic or social purpose since the early 1970s; the mill operation had long since been closed, and the headpond was filled with sediment and debris – no longer used for recreational skating as it was in the past century. Based on Mi’gmaq oral tradition and the fact that even smaller neighbouring tributaries of the Petitcodiac River watershed historically sustained Atlantic Salmon runs, Riverkeeper assumed at this stage that previous to the dam having been built over a century ago, that this tributary also sustained an Atlantic Salmon run.

Project Goals

- To develop a framework and a model to decommission an abandoned dam impeding fish passage in the Inner Bay of Fundy in order to assist in the recovery of the Atlantic Salmon, using similar models developed in Canada and the United States.

- To develop consensus and community support around an environmentally, socially and economically acceptable plan to decommission the abandoned Humphreys Brook dam.

- To draft the actual plans to decommission the Humphreys Brook abandoned dam, including an assessment of the feasibility of introducing or reseeding this tributary with Atlantic Salmon, should this be the recommendation of the IBoF Salmon Recovery Team.

Species at Risk

- Inner Bay of Fundy Atlantic Salmon.
- Other indigenous fish species from the Petitcodiac River system extirpated or in serious decline that support the overall ecosystem food chain.

This abandoned dam was successfully removed during the summer of 2013. Read about it here in our Success Stories.

Mill Creek

Mill Creek abandoned Navy Dam project

millcreek

In the fall of 2003, Riverkeeper obtained funding to research and direct a detailed assessment into either restoring fish passage or removing the abandoned Navy Dam in Riverview. The project included a topographical survey, a sediment management plan, a deconstruction plan and a fish survey. Riverkeeper carried out a public consultation during the study and approached the owner (Town of Riverview), the Department of National Defence and other prospective partners to fund a $300,000 project to decommission the abandoned dam. In 2004, the Town of Riverview subsequently voted a resolution to keep the abandoned dam in place and build a more expensive fishway to meet the requirements of the federal Fisheries Act (estimated at over $1 million). The abandoned dam continues to impede fish passage, in violation of the federal Fisheries Act.

Description

• Dimensions of structure: 55 metres long by 6 metres high• Area impounded: Approximately 12 acres• Area affected: Approximately 60 km2• Length of stream: Approximately 25 kilometres

Built around 1950, the dam on Mill Creek in Riverview was intended to be used as a reservoir in case of fire at the Naval Base on Ruddymeade Road, a facility which was closed down in 1970. In the following years, the Town of Riverview acquired title to the dam and the adjacent land from the Department of National Defense.

Plans are to develop the area as a nature/recreation park. Today, siltation prevents the pond from being used for aquatic activities and the dam no longer serves its intended purpose, aside from being designated as an emergency water supply should a significant forest fire occur in the near vicinity. Cracks have also been detected in the dam, showing signs that the structure is weakening.

Negative impacts of the abandoned Navy Base dam on Mill Creek:

  • Creates total obstruction to fish passage
  • Prevents nutrients from flowing downstream
  • Shows an accumulation of sediments in upper pond
  • Has a direct impact on the stream’s biodiversity
  • Poses a potential threat to public safety, and should this abandoned dam fail, poses a potential threat to the ecology of the Petitcodiac River system

The Mill Creek Watershed Group, a local environmental committee located in Riverview, was actively involved in the restoration of Mill Creek and its members were advocating for the removal of this abandoned dam, as well as the creation of a nature/ecological park in the drained headpond’s basin once the stream is restored.

Project Objectives

The objective of the project was to carry out a preliminary assessment to determine future options for the abandoned Navy Dam located on Mill Creek, a 60-km2 tributary of the Petitcodiac River watershed situated in East Riverview. Built in the early forties by the Canadian Navy, the dam was built in order to create an artificial reservoir to be used in case of forest fires. The Canadian Navy has long since abandoned the dam, now owned by the Town of Riverview, and neither the dam nor the reservoir have been used for some time now. Having outlived its intended use and beginning to show signs of structural weakness, the question of what to do with the dam remains to be decided. The Petitcodiac Riverkeeper and the Mill Creek Watershed Group in partnership with the Petitcodiac Watershed Monitoring Group (PWMG) and the Town of Riverview undertook a project in 2003/2004 aimed at examining options for the dam’s future in order to assist the various stakeholders in the community to better understand the choices available in order to improve the stream’s water quality and habitat.

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