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Category Archives: Dam Removals

Teeterville Dam Class Environmental Assessment – Final Report

Teeterville Dam, Big Creek

ORA’s June 2025 letter raised five specific concerns regarding the AET matrix: the misclassification of climate change criteria within the Technical/Engineering category; the underweighting of Natural Environment (25%) relative to Social/Cultural (40%); the exclusion of methane emissions from reservoir sediments as a scored criterion; the failure to credit the carbon sequestration potential of riparian habitat restoration; and the heavy weighting of upfront construction costs (70% within the Economic category) over long-term lifecycle maintenance costs (30%).

The Final Report acknowledges the scientific foundation of several of these concerns in narrative text, including that shallow reservoirs emit methane from anoxic bottom sediments, and that dam removal would convert the reservoir from a greenhouse gas (GHG) source to a carbon sink through vegetation establishment. However, none of these recognized ecological and climate realities were incorporated into the scoring framework. Acknowledgement in narrative text, without corresponding weight in the evaluation matrix, has no bearing on the comparative scores or the preferred alternative selection. The Final Report does not explain why these science-based concerns were excluded from scoring.

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Section 16 Order Request: Allan’s Dam, Spillway and Sluiceway, City of Guelph, Speed River

Infrasture stacked on top of and surrounding Allans Dam and Spillway.

The handling and outcome of the Macdonell and Allan’s Structures MCEA constitute a serious procedural failure that infringes on the constitutionally protected Aboriginal and treaty rights of the Six Nations of the Grand River, the Mississaugas of the Credit First Nation, and the Haudenosaunee Confederacy. Throughout the five-year MCEA process, the City withheld essential information—including the dam’s true age (155 years), the absence of any structural or subsurface assessment, the deteriorated condition of the spillway, and the 2018 OSIM recommendation for a LRIA-compliant Dam Safety Review. None of this was disclosed to Indigenous rights holders, despite the project’s direct implications for the Speed River, its fish, habitat, water quality, and flood risk.

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One Project, One Review: Co-operation Agreements for the Assessment of Major Projects

Vermilion River – Our grandchildren’s future with water!

ORA’s recommendations call for enforceable public-participation standards, clear cumulative-effects gatekeeping, transparent reasons for any federal withdrawal, Indigenous-led consultation processes, and a national commitment to freshwater conservation and resilience. While ORA’s work spans mining (including Ring of Fire), hydropower, wastewater-treatment facilities, and dam-safety issues, these examples illustrate, rather than shift, the focus to the urgent need for fair, transparent, science-based federal oversight.

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Speed River: Macdonell and Allan’s Structures Municipal Class Environmental Assessment

Allan’s Dam & Allan’s Dam Bridge, Guelph, Speed River.

Our own research revealed that Allan’s Dam is a legacy mill dam, originally constructed in the 1830s to power Allan’s Mill—one of Guelph’s founding industrial sites. Sometime later, the structure was adapted for hydroelectric generation, likely in the early to mid-20th century. It is our understanding that this facility has not generated electricity for several decades and now functions only as an aging dam, concrete spillway and sluiceway, impounding a shallow headpond on the Speed River. It appears that this infrastructure no longer serves any useful purpose while continuing to fragment habitat, degrade water quality, and emit copious amounts of carbon, methane, and nitrous oxide into the atmosphere.

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Springbank Dam Decommissioning, Thames River, London

January 2016

The Springbank Dam on the Thames River is in phase II of decommissioning.   The 4 gates and concrete deck will be removed throughout this summer and fall.  The upright columns will remain in the river.

ORA, the Thames River Anglers Association, and several other supporting organizations made a formal request to the City of London in January of 2016 to remove the dam, which was expected to be repaired upon receipt of a long-awaited lawsuit settlement.  ORA and partners made two compelling submissions laying out the many benefits of dam removal, and in 2019 London City Council made a unanimous decision to decommission the dam.


Teeterville Dam Class Environmental Assessment

Teeterville Dam, Big Creek

The Ontario Provincial Climate Change Impact Assessment (2023) utilized historical and projected future climate data as fundamental components to assess the risks and consequences of extreme weather events, as well as projections of future climate risks. It reports that “changes in Ontario’s climate are expected to continue at unprecedented rates… and it will pose indirect threats to things like water availability and water quality.” [i] The report further indicates that southern Ontario will see upwards of 55-60 extreme heat days annually by the 2080s—a fourfold increase from the current annual average of 16 days. These changes threaten stream temperature regimes, species survival, wetland retention, and seasonal flows. Failing to categorize and weight these risks appropriately jeopardizes the matrix’s integrity and relevance to present-day climate conditions.

Climate change will have severe negative effects on water quality, water quantity, aquatic life, habitat, riverine ecosystem sustainability, and communities that rely on these freshwater resources. Alternatives 1, 2 and 3 would leave a dam in place, diminish stream resilience, degrade water quality and quantity, and place the creek’s entire ecosystem at increasingly greater risk.

[i] Ontario Provincial Climate Change Impact Assessment, Technical Report, January 2023.  Online: https://www.ontario.ca/files/2023-11/mecp-ontario-provincial-climate-change-impact-assessment-en-2023-11-21.pdf

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Teeterville Dam Conservation Ontario Class Environmental Assessment, Big Creek

Teeterville Dam, Big Creek

Long Point Region Conservation Authority (LPRCA), through their consultant Montrose Environmental (Montrose) (formerly Matrix Solutions Inc.) is undertaking a Conservation Ontario Class Environmental Assessment (CO Class EA) for the Teeterville Dam, within the Hamlet of Teeterville.

While a dam and reservoir have existed at, or near, the current site since the 1830s, primarily functioning to power local grist and sawmills, the existing structure was constructed in 1915, after a flood destroyed the original wooden dam structure.

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Vittoria Dam – Chose Alternative 5

Chose Alternative 5

Excerpt from the Final Environmental Study Report:

In this alternative, the dam would be decommissioned through the removal of all available operational dam elements related to flow control including the stop logs and gains, as well as the low-level sluice gate bypass system. The decommissioning of the flow controls would be undertaken over an extended period of 2 to 3 years or more, to limit potential remobilization and offsite transport of accumulated sediments within the existing reservoir and to provide time for the sensitive flora and fauna of the area to acclimate to changing conditions. Continue reading


Hurray!! The Springbank Dam gates are finally being removed from Thames River

  • January 2016

In late October of this year the City of London began the work of removing the Springbank Dam gates on the Thames River.  The four 5.49-metre-high x 15.24-metre-wide gates and mechanical building that once operated them are in the process of being removed.

For the last 16 years these 4 gates have been lying on the bed of the river backing up sediment, blocking stream flow and impeding fish passage. In 2008 one of the four gates failed to function, and became the source of a lengthy litigation battle.

In 2015, after the City of London won the litigation, Council fully intended to repair the dam once the proceeds from their litigation were finally received. However, in January of 2016, the ORA, Thames River Anglers’ Association and 19 other partners, representing 200,000 members, sent a joint submission offering compelling reasons for why it would be in the best interests of the City and the health of the Thames River to decommission the dam.  Shortly after the City of London commenced a One River Master Plan, engaging the public and stakeholders, to help decide how far to go in decommissioning the dam.  On 9 January 2018 our coalition responded to the Environmental Report with another comprehensive submission.  On 14 January of 2018 London City Council made a unanimous decision to remove the gates and control building.  The BIG WHEEL turns slowly but the gates are coming off. 🎣🐟  The full extent of our advocacy work can be viewed here.


Howson Dam Removal Project – North Maitland River

  • Howson Dam - North Maitland River, Wingham, Ontario.

The Howson Dam Removal Project on the North Maitland River began in July of this year and is expected to be completed sometime this Fall.  ORA advocated strongly for the removal of the Howson Dam instead of repairing or reconstructing the dam that was so clearly having negative effects on water quality both upstream and downstream of the dam.  Stay tuned for more pics as the Project progresses.  Removal of the Howson Dam reconnects approximately 100 km of uninterrupted Chinook Salmon and Rainbow Trout habitat on the Maitland River system, from Wroxeter all the way to its outlet at Lake Huron in Goderich.

Check out ORA’s role in getting this done – click here and scroll down.

On 23 and 24 June 2017, during an extreme rain event, the Gorrie Dam washed out, and the Howson Dam was at capacity when all the stop logs could not be removed.  Both dams failed when 175 mm of rain fell over a 7-hour period, placing more than 150 property owners at risk.  This severe rain event and flood resulted in an estimated $11 million in damages in the Town of Harriston and broke previous records by approximately 40%.  It was the second-highest flow on the North Maitland in the 48 years of record.

All remnants of the Gorrie Dam were removed, and the river was reconstructed in 2021.  Another ORA advocacy success!