Community Blog

The Invisibilized Costs of Hydroelectricity

The pristine river systems of the world have been dammed for various purposes like irrigation, hydroelectricity, and storing water in reservoirs for drinking purposes. Hydroelectricity is generated by the energy in a flowing river. The hydroelectric dams convert the potential energy stored in the water reservoirs into kinetic energy as the water flows through the dam rotating the turbines. The amount of energy generated depends on the flow of the water, so a lot of the hydropower stations require extensive construction to maximize the ability to control the water levels and flow rates.

In the process, a lot of the decision making depends on economic goals rather than environmental or social implications. This means there are numerous construction works required which also means flooding the nearby lands to get the construction started. The environmental costs of constructing a hydroelectric dam are often overlooked. The hydroelectric companies use “clean”, “green” and “sustainable” as a marketing tool to promote hydroelectricity as environmentally sustainable. However, that is simply greenwashing.

Greenwashing is used by organizations to fit a public image that deems them environmentally friendly. Since rivers are renewable resources, we might think that hydroelectricity is one of the cleanest energies that could be produced. But is hydroelectricity as clean as it claims to be?


What are hydroelectric dams hiding?

Now, let’s talk about some of the implications of using hydroelectricity. Often, the land nearby is flooded which means it has social and environmental costs. The aquatic life is affected, the biodiversity declines both on land and in the water and often large-scale projects displace communities.

In Canada, for instance, Chemawawin Cree Nation was forced to relocate when Manitoba Hydro began damming the Saskatchewan River to start developing the Grand Rapids generating station in the late 1950s year (Loney, 1987). This relocation was the direct outcome of the construction of the dam, which altered the water levels of the river, causing a giant reservoir of approximately 3500 km2 to form in Cedar Lake. This development flooded approximately 856 km2 of delta land. Before the Grand Rapids Hydro Development, Manitoba contained “one of the last four extensive delta areas of wetland wildlife habitat, remaining in the relatively unspoiled condition in North America (Loney, 1987, p.58).

As a result, Cedar Lake is now filled with debris caused by flooding, and this has thus impacted the fishing opportunities in the communities. The abundance of moose, deer, and waterfowl in the area before the hydro development also means that hunting and trapping was another economic activity of Chemawawin Cree Nation (Loney, 1987). The hydro development led to declines in the biodiversity and thus affected sustenance for the people resulting in forced relocation. They had to relocate because their primary economic activity, i.e., fishing was impacted. They were relocated to the shores of the Cedar Lake which is filled with the debris caused by the flooding for the hydro dams (Loney, 1987, p.58)

When we talk about hydro dams, an issue often overlooked is the release of mercury into water and soils. There is not a lot of research surrounding this issue, however, this is something we cannot neglect. In addition to changing river dynamics, the flooding can lead to the transient contamination of food webs by mercury (Hg) and methylmercury (MeHg) contamination.


How do dams relate to mercury?

Mercury is an element that occurs naturally in the environment. Natural processes such as volcanic eruptions, the weathering of the rocks and sea vents can release mercury into the atmosphere and biosphere. Mercury has some toxic characteristics as it bioaccumulates and biomagnifies in the environment. This means it concentrates in the fatty tissues and we can find higher levels of mercury in the higher trophic levels in a food chain due to its biomagnifying characteristics.

For humans, most of the exposure comes from consuming the fish and other animal species exposed to mercury. Methylmercury is readily available in other parts via the bloodstream. Methylmercury is created when the “inorganic mercury circulating in the general environment is dissolved in the freshwater or seawater” (Hong et al., 2012).

Going back to our example on Cedar Lake, hunting and trapping opportunities have declined dramatically over the recent decades. And, in 1970-73, the lake was closed for fishing because of mercury contamination which can be directly linked to the construction of hydroelectric dams (Loney, 1987). There were 6 reported deaths among the fishing communities caused by the mercury contamination in the waters because of the hydroelectric project (Loney, 1987).

Another hydroelectric development, based in Northern Quebec, called the James Bay Project, received public concern, especially around the preparations for the Great Whale phase in the late 1980s. Concerns were already emerging from the first phase of the project that was development in the 1970s (Linton, 1991). This included the methylmercury contamination of waters in the reservoirs and mercury accumulation in the fishes in the river (Linton, 1991). When the James Bay Project was announced, the Bourassa government did not inform the Inuit and Cree people living in the affected region (Linton, 1991). Fish normally contain certain levels of mercury but after the construction of reservoirs, levels of organic mercury in fishes rose for several years as per Hydro Quebec’s research.  As the communities were dependent on fish for their survival and sustenance, mercury poisoning caused harmful disruption in their traditional way of life.

The impacts of hydro dams in the communities can be seen in terms of forced relocation, destruction of the traditional ways of lives for the Indigenous peoples and mercury contamination in the flooded rivers. These are only to name a few and there are wider implications beyond these. There is a need for more global awareness regarding the hidden costs of the hydro dams and a need for more political involvement in such mega projects. An environmental assessment could be a great tool to analyze the potential impacts of such projects. Now, we will move on to discuss some of the possible ways of challenging the status quo for dam development and how it correlates to the Paris Agreement.


What is the Paris Agreement and what does it mean for hydroelectricity?

The Paris Agreement is a legally binding international treaty on climate change. It was signed in December of 2015 and entered action in November of 2016. Its focus is to reduce greenhouse gas emissions to limit global warming to below 2 degrees Celsius, preferably 1.5 degrees Celsius. The Agreement focuses largely on the impacts of fossil fuels and how these need to be cut, while the impacts and emissions from hydroelectricity are often overlooked.

Since the impacts of climate change can be felt across the globe in terms of droughts, flooding, storm surges etc., it is vital to divert the reliance on fossil fuels and invest in other alternative energy that does not inflict impacts on communities. Since hydroelectricity has been used for centuries, it still accounts for over half of the renewable energy generated worldwide. But it is time that the public is made aware of the impacts of hydroelectricity and the injustices it brings in the affected communities.

Echoing the concerns raised about hydroelectricity being unsustainable, an alliance of over 340 organizations from 78 countries with diverse backgrounds and an array of people released a call of action to the parties of the UNFCCC Conference of the Parties (COP-26). They issued a joint statement rejecting “attempts by the hydropower industry to secure scare climate funds to finance a new wave of hydropower projects.”

The statement highlights the need for “just and sustainable solutions to the climate and biodiversity” which supports the role of the natural environment and promotes climate resiliency through involving the Indigenous peoples in the climate discourses.

The statement also portrays that the investment in the hydropower projects would mean that it would worsen the climate crisis by “exploding methane emissions and diverting scarce climate funds from meaningful energy and water solutions in a world that is already grappling with severe impacts of climate change”.

As hydroelectricity usage is expected to rise in the future to meet the global energy demands, there is an urgency to research more about the impacts of methylmercury contamination on humans, animals, and the environment. Although hydroelectricity is viewed as a “clean” energy, it is not as clean as it claims to be. So, more acknowledgement and inclusion of community knowledge is necessary to see the true implications of hydroelectricity on the flooded communities in terms of mercury poisoning and the many other impacts experienced.

So, the goal here is to listen to and work with communities throughout decision making processes to understand their hopes and solutions in achieving energy security. Achieving the goals of the Paris Agreement would need such community engagement and a huge investment in alternative sources of energy.


Reflection on Possible Solutions

As users of hydroelectricity, we have the power to demand a transparent report from our providers. Often, consumers do not have a say in choosing the source of electricity for our utilities because the governments invest in developing hydroelectric dams.  Here, in Manitoba, the utility company is a monopoly so the only choice for the consumers is hydroelectricity through Manitoba Hydro. However, we have seen people choosing to produce their own electricity by using solar for instance in their cabins.  But, powering the entire house or an institution with the alternate energy still requires changes in politics and policies.

Citizens have the power to vote for parties that support alternative energy. To do so though, consumers need to be aware of the implications of hydroelectricity. The dams are not located inside the cities, so we never think of where our electricity is coming from. I think the younger people must be made aware of the condition of generating power as future lies in their hands. And the best way to reach the younger audience would be the use of social media. The research about the hidden costs associated with the hydro dams is still stuck in the environmental field, so to reach out the wider audience, awareness through social media could be a great tool.  Our electricity should not be at the cost of the environment and the communities surrounding the hydroelectric dams.


Written by Eliza Maharjan, Environmental Student 



Hong, Kim, Y.-M., & Lee, K.-E. (2012). Methylmercury exposure and health effects. Journal of Preventive Medicine and Public Health, 45(6), 353–363.

Linton. (1991). Guest Editorial: The James Bay Hydroelectric Project — Issue of the Century. The Arctic, 44(3), iii-iv.

Loney. (1987). THE CONSTRUCTION OF DEPENDENCY: THE CASE OF THE GRAND RAPIDS HYDRO PROJECT. Canadian Journal of Native Studies, 7(1), 57–78.

Roburn, S. (2018). Power from the north: The energized trajectory of indigenous sovereignty movements. Canadian Journal of Communication, 43(1), 167-184.

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