[5] The project has drawn considerable opposition from several quarters due to its planned flooding of agricultural land, damage to the local environment, high construction cost, possible alternatives, and the uncertainty of future electricity prices and demand in the province.

[6][7] In addition, over 200 scholars, as well as the Royal Society of Canada, have expressed concerns to the federal Liberal government, citing weakness in the regulatory review process and the environmental assessment for the project.

The fourth proposed dam on the British Columbia segment of the Peace River, Site E, near the BC–Alberta border, was removed from the planning process during hearings in 1982.

[15] The commission was critical of BC Hydro's forecasting methods, declaring that it neither explicitly took energy prices into account nor relied on statistically significant past patterns of behaviour.

As of 2017 these annual purchases are about four times the capacity of Site C. Once the initial contracts with BC Hydro expire, these independent producers may be free to export their electricity.

To avoid duplication, the governments of Canada and British Columbia set up a cooperative federal-provincial environmental assessment, including a joint review panel (JRP) process.

[20] By March 2016, site clearing, attempts at bank stabilization and the search for bedrock took the majority of BC Hydro's focus - there were no "works" in the ground; the diversion tunnels had not yet been started.

BC Premier Christy Clark's stated intention was to get dam construction "to the point of no return" by the time of a scheduled general election in May 2017.

[21] The project has sparked controversy for several reasons: First Nations treaty rights are at issue,[22] the dam is thought by many to be economically unviable, and there are concerns about the loss of agriculturally productive land and the overall environmental impact.

[27] At the invitation of the British Columbia Utilities Commission, Deloitte published a report on the project, and noted that it's likely to miss a crucial river diversion deadline; this will bring the cost to just under $10 billion.

[19] On 2 August 2017, following a Provincial election, the NDP government requested that the BCUC evaluate the cost to BC Hydro ratepayers of continuing, suspending or terminating construction of the Site C dam.

[39] Following the release of the Final Report the BCUC responded to additional questions from the BC government which clarified that: The making of Williston Reservoir affected many parts of the neighbouring environment.

In “This Was Our Valley,” authors Shirlee Smith Matheson and pioneer poet Earl Pollon describe BC Hydro’s hopes for the reservoir, thinking it would bring new chances for forests, minerals, and easier fishing and hunting access.

Despite what was hoped, building the Williston Lake reservoir has made big changes to the environment, affecting the natural homes and systems in the area.

The Joint Review Panel accepted BC Hydro's assessment that "production from the Peace River bottom lands is small and is certainly not important in the context of B.C."

The Panel's assessment of earning potential in the next several decades led them to conclude: "The highest and best use of the Peace River valley would appear to be as a reservoir.

[44] According to David Suzuki, flooding valuable farmland to build the dam will undermine Canada's international commitments under the Paris Agreement.

"[45] In April 2015, the federal and provincial governments named a Joint Review Panel to hold a public hearing on Site C.[46] In addition to a long list of recommended changes, their assessment stated: "Despite high initial costs, and some uncertainty about when the power would be needed, the Project would provide a large and long-term increment of firm energy and capacity at a price that would benefit future generations.

"[47] In reference to the Paris climate accord, Site C is predicted to prevent approximately 30 to 70 million tonnes of carbon dioxide from being generated in the atmosphere.

Justin Trudeau commented "I think anything we can work together inter-provincially or nationally [to get] emissions down, emphasizing hydroelectricity, creating opportunities to get off coal, to get off natural gas, where possible, is good for the country.

[52] Beavers hold significant cultural importance for the Doig River Nation (DRFN), underscoring the essential relationship between the two entities.

This study aims to address the cultural significance of beavers to the DRFN community and protect Treaty Rights, emphasizing the potential cumulative adverse effects of various resource sectors, including hydroelectric dams, within Treaty 8 territory.”[52] In November of 2023, Doig River First Nation elders led a burial ceremony for ancestral remains exhumed from the Site C reservoir flooding zone.

And so, it’s totally different for us to move a grave, but we don’t want it [drowning] underwater.” Attachie's sentiments show how the ceremony's implications as a departure from cultural norms.

[14] The Peace River Valley falls within the bounds of Treaty 8, which recognizes First Nations’ right to hunt, trap,and fish throughout the region.

The WAC Bennett and Peace Canyon Dams and their reservoirs have altered the landscape in the region, imposing significant environmental impacts that have not been addressed to this day.

Therefore, Treaty 8’s position is that this project is unacceptable and that alternative solutions to meeting the province’s energy needs must be assessed in a meaningful way”.

[55] In order to mitigate impacts on wildlife, BC Hydro has proposed trapping, tranquilizing, and relocating the bears prior to the dam being filled.

[56][55] B.C Hydro’s proposal to leave 45 structures of construction debris on the bottom of the Peace River upon flooding has raised serious questions about the well-being of fish and their ecosystem within the community.

BC Hydro determined in the 2013 Integrated Resource Plan, DSM 5, that more than double the amount of power from Site C could be obtained from conservation at up to $45/MWh.

[61] British Columbia has committed to reducing greenhouse gases to 33 per cent below 2007 levels by 2020; however, the province is far short of that goal, only achieving a 6.5% reduction as of 2015.