Renewable Energy Resources: Hydropower

Hydropower is one of the oldest forms of renewable energy in the province. In fact, in the 1950s, nearly 50% of the province’s power came from hydropower.[1] Although today the proportion of hydro is lower, this is in large part due to increased electricity needs of a growing population and the ready exploitation of fossil fuels. Today, most of the province’s future hydropower potential is located in the Athabasca, Peace and Slave River basins located in Northern Alberta, with only a small percentage coming from the Red Deer River basin and the North and South Saskatchewan River basins.[2]

Hydropower is generated when a power source (in this case moving or falling water) is used to turn a propeller-like piece called a turbine, which then turns a motor that produces electricity.[3] In order to build a hydropower station, large rivers are dammed up, allowing enough water to collect to generate the necessary electricity.[4]

Sounds too good to be true…

Unfortunately, it is. Hydropower is considered to be a renewable resource and is not itself directly polluting but it does come with many environmental pitfalls. For example, dams that create a reservoir or that divert water (called a run of river hydropower plant) may obstruct fish migration, change the natural water temperature, water chemistry, river flow characteristics, and silt loads.[5]

These large-scale changes can have dramatic effects on the plants and animals that live in the river and on its shores. For dams that create a reservoir, this flooded area may also release a significant amount of methane due to decomposing plants. In turn, this methane contributes to climate change.[6]

The problems with hydropower seem to be consistent regardless of the size of any particular site; and site selection, rather than size, is often seen as the best way to reduce the environmental impacts of hydropower.[7] Proper site selection requires a close look at both the downstream effects of a particular project (for example – is it located near a prominent fishery or town that depends on clean drinking water?) and cumulative effects (how many other hydropower stations already exist in this river system and how do they affect one another?)[8]

You can read about other examples of the environmental and health problems that can occur when cumulative effects are not well regulated in our Toxins & Waste section here.

One way to potentially deal with the changes to a river’s landscape is to incorporate a mitigation hierarchy similar to the one currently in place for wetlands in Alberta.

Click here to read our wetlands section to get more background on this policy.

The idea behind this hierarchy is that if you cannot avoid the displacement of a river’s natural habitat, you will attempt to mitigate damage such as through proper site selection, and if that cannot be done, then you will compensate by creating a reclamation site focused on replicating the natural habitat as much as possible.[9] A successful mitigation hierarchy will require strong regulation ensuring that the hierarchy is adhered to and that there are options for enforcement in the event that it is not.

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[1] Alberta Culture & Tourism, “Hydroelectricity in Alberta Today” online:

[2] Alberta Culture & Tourism, “Hydroelectricity in Alberta Today”.

[3] Canadian Hydropower Association, “Five things you need to know about Hydropower” online:

[4] The USGS Water Science School, “Hydroelectric power: How it works” (2 December 2016) US Department of the Interior & US Geological Survey online:

[5] Peter H. Gleick, “Environmental Consequences of Hydroelectric Development: The Role of Facility Size and Type” (1992) 17:8 Energy 735 at 738-745.

[6] United States Environmental Protection Agency, “Understanding Global Warming Potentials” (14 February 2017) online:

[7] Peter H. Gleick, “Environmental Consequences of Hydroelectric Development: The Role of Facility Size and Type” at 735.

[8] Dr. Ute Collier, “Hydropower and the Environment: Towards better decision-making” (Paper submitted to the United Nations Symposium on Hydropower and Sustainable Development, to be held in Beijing, 27-29 October 2004) [unpublished].

[9] Dr. Ute Collier, “Hydropower and the Environment: Towards better decision-making”.




Energy Law

Lesson Plan: Fundamentals of Environmental Law
Lesson Plan: Canadian Charter of Rights and Freedoms
Lesson Plan: Tragedy of the Commons
Lesson Plan: Climate Litigation

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