National Geographic Society Newsroom

Not-so-Clean Hydropower is Damming Us All

By Natalie Anderson While I was in Fort Smith, Northwest Territories (NT), Canada, this summer observing and measuring wood floating down the Slave River for my dissertation work on Mackenzie River driftwood, I attended a local town hall meeting facilitated by Alberta member of Parliament Linda Duncan about what the town of Fort Smith can...

Slave River in Canada, spot of a proposed hydropower plant
Kayakers enjoy the rapids at one of the proposed locations for the Slave River Hydropower project. This is truly one of my favorite spots in the world. Along with a nesting colony of white pelicans I migrate North to visit it year after year. (Photo by Leif Anderson)

By Natalie Anderson

While I was in Fort Smith, Northwest Territories (NT), Canada, this summer observing and measuring wood floating down the Slave River for my dissertation work on Mackenzie River driftwood, I attended a local town hall meeting facilitated by Alberta member of Parliament Linda Duncan about what the town of Fort Smith can do to ensure that they will have their voices heard at a national level regarding future hydro development of the Slave River corridor in the face of the river’s de-listing as a navigable waterway in 2012 (Northern Journal, Aug 6 2013, CBCnews, Oct 18, 2012).

The Canadian navigable waterway act  is one of the country’s oldest pieces of legislation, dating back to 1882, and provides federal oversight to any proposed project in a river, lake, or ocean that could float a canoe.  Prior to 2012, more than 2 million waterways were listed.  Now, fewer than 200 are.  Most proponents of the de-listing feel that it will eliminate redundant provincial-federal red tape, streamlining projects on small ditches and streams.  They maintain that large waterways are still protected.  The Slave River is big (~0.5 km wide with summer flows ~4,000 cms), has a rich history as a shipping/trading corridor, but is no longer protected even though waterways upstream and downstream are.

Most townspeople (NT residents) are making connections between this seemingly cherry-picked delisting of the Slave River and a large-scale >800 megawatt hydropower project (and 500 kw/500 km North-South transmission line) proposed by TransCanada and ATCO Power to be built in their backyard just a few kilometers upstream in Alberta (Calgary Herald, March 20, 2008).  If the Slave is not re-listed federally, the Government of Northwest Territories would have little say in a project that, built by Alberta, would provide power primarily for southerners and mining industries while the environmental impacts would be shouldered by northern communities (Northern Journal, Aug 13 2013).

In speaking to me about the hydropower project, François Paulette, elder and environmental leader for the Smith’s Landing First Nations Band–whose land would be flooded–said: “Why do they call it clean energy, where do they come up with this word, ‘clean’? It is not clean.”

This strong stance by Smith’s Landing is right now the main impediment to the project going forward (Northern News Services, Feb 18, 2013).

As a geologist who studies rivers (a fluvial geomorphologist), I couldn’t agree more with François and his intuitive understanding of the land. This year, the World Bank, after two decades of refusing to fund large hydropower projects, is back in with big hydro in order to combat world poverty due to climate change (Hydro World, May 30, 2013).  Dam building for hydropower, especially in developing countries, is occurring at alarming rates (The Atlantic, May 20, 2013).  As a scientist and concerned global citizen, I will use the proposed Slave River project to help me make my case against big hydropower as a source of clean, renewable energy.

People deserve better reasons to oppose this than, “it will degrade the environment,” “it will flood a pretty place,” or “we will lose such and such animal or plant.”  How about this: large dams are societal hazards, pollutants, non-renewable, and economically unsound.

Large Dams are Societal Hazards

When large dams are built they often require relocation of people from lands that are to be flooded.  The number of people displaced by upstream flooding can be relatively small, as in the case of  the Slave River project, or can be huge, as in the case of the 1.2 million people displaced from the construction of the Three Gorges Dam in China (Biello, 2009).  In either case, the strife encountered by displaced people is very real and long-lasting, no matter the compensation offered.

It is estimated that globally, between 40-80 million people (mostly the poor and indigenous) have been displaced, usually involuntarily (Namy, 2007).  The displaced suffer economic and cultural declines as well as high rates of mental and physical illness (see Namy, 2007 for further explanation).  Political conflict can also occur because dams are built upstream by one group of people or nation, depriving the downstream group or nation of its water.

Many reservoirs themselves are recognized health hazards; they can be breeding grounds for waterborne illnesses spreading infectious disease , they promote the growth of toxic algal blooms impacting drinking water, and they accumulate contaminants delivered from up basin in the reservoir sediment (Wildi et al., 2004). Heavy metals (often mercury) and other toxins cascade up from the benthic zone through the food web, becoming concentrated in fish, birds, mammals and humans.

For people in Fort Smith, this should be of special concern since the Athabasca oil sands are upstream (Northern Journal, July 8 2013).  Their sister community of Fort Chipewyan has already noticed the negative impact the oil sands have had on the environment and their health (Vancouver Observer, June 30, 2013).  A long-anticipated cancer study is about to begin (Fort McMurray Today, Feb 20, 2013).

After large dams are built large populations come to depend on them and thus they become a weak point in water, energy, flood, and food security.  A recent example is the threat that the Rim Fire has had on the quality of drinking water and supply of electricity from Hetch Hetchy Reservoir to 2.5 million people in San Francisco (CBS, Aug 28, 2013).  Communities which would not exist without the presence of the dam, such as Las Vegas, are especially at risk should the dam lose capacity or cease to operate.

While dams do provide flood control for average flooding events, they give people an erroneous sense of security resulting in extensive development on floodplains.  During big infrequent events, these communities are flooded and loss of property and life is the consequence (Prairie Fire, May 2009). The detrimental effect that dams have on downstream riverside ecosystems leads to decreases in food security by reduction of game, fish, and fertile farmlands–impacting 472 million river-dependent people worldwide (Richter et al., 2010).

Due to the USA’s dependence on dams for water and electricity and the threat to civilian lives if one should fail, it is no surprise that after September 11th security was heightened at most large dams in the U.S. to protect citizens against organized or individual terrorist acts (CSO, Oct 26, 2009).

Large dams are “natural” disasters waiting to happen. If a dam should fail for any reason (poor construction/maintenance, earthquake, attack, etc.), the catastrophic flooding is sure devastation for communities living downstream.  In addition, reservoirs can reactivate faults and trigger earthquakes because their weight places stress on major fault lines and lubricates existing fractures with water.  Research indicates that this may be what caused the Sichuan disaster in May 2009, leaving 80,000 dead (The Telegraph, Feb 2, 2009).

Although the proposed Slave River dam will not have a large reservoir behind it, it is likely that it would increase groundwater, probably exacerbating an already recognized problem with landslides.  In 1968 a large landslide that delivered a large portion of the town into the river is still vividly remembered by residents (Northern Journal, Aug 26, 2013).

Dams can be a hazard affecting people globally, not just those downstream.  For example, dams slightly change the tilt of the earth’s axis and gravitational field (NY Times, March 3, 1996) and can impact extreme precipitation patterns (Hossain and Jeyachandran, 2009) and global circulation patterns (Maser, Aug 23 2012).  Dams also increase coastal erosion by depriving deltas of sediment.  This, coupled with sea level rise, is a severe concern for shoreline communities since it increases their risk during large storm events (Stewart, 2005).

Large Dams are Polluters

It is estimated that global hydropower currently produces the energy equivalent of several thousand coal-fired power plants (Biello, 2009), and thus is viewed as an appealing clean alternative. However, large hydroelectric plants are very dirty polluters themselves.  Often hydopower projects are financially feasible because they have customers from high carbon-emitting industry partners.  ATCO Power has made it clear that they consider the presence of the Athabasca oil sands as a plus because the miners of that material would be guaranteed long-term purchasers of their energy. Financing the high cost for construction will be a safe bet for Alberta since ATCO won’t likely default on their loans (Northern Journal, Jan 15, 2013).  It is ironic then that a ‘clean’ energy source will mostly provide energy for the rapid growth and expansion of not-so-clean energy extraction.

One of the most pressing global pollution issues today is nitrogen pollution from extensive use of fertilizers to the world’s oceans, causing the spread of dead zones and the collapse of world fisheries (NPR, Aug 18, 2008).  Dams play a large role in the export of this nitrogen to the ocean by decreasing the frequency of inundation of water onto floodplains, thus decreasing a river’s ability to denitrify its waters before it gets to the ocean (Gargel et al, 2005).  After the completion of large dams on the Slave and Athabasca, it is likely that residents of the Great Slave Lake will start seeing algal blooms to the detriment of their fisheries, especially as the climate continues to warm.

Scientists have shown that hydropower contributes significantly to the greenhouse effect through the release of substantial amounts of methane gas to the atmosphere.  For example, it is estimated that in 1990 the Tucuruí Dam in Brazil released more greenhouse gases to the atmosphere then Sao Paulo (Scitizen, Jan 9, 2007).  In large bodies of water, methane gas is found in the colder waters near the lake bed.  In natural waters this methane gas is released as bubbles slowly rise to the surface (Bastviken et al, 2005).  However, hydropower facilities substantially increase methane release to the atmosphere by using the cold water, high in methane, from the bottom of the reservoir to run through their turbines.

Large Dams are Unsustainable

Hydropower is often touted as a renewable, sustainable form of energy because water is commonly seen as a renewable resource.  While small hydropower in the form of instream turbines probably is renewable, any hydro project that puts a dam across a river isn’t.  All dams have a useful working lifetime and for many dams this is shorter than you may think. The Hoover Dam has reduced power production by 23% since it came into operation, and in 2010 was at the lowest levels it has been since the 1930’s when it was filled (Circle of Blue, Sept 20, 2010).  Water levels in the lake will conceivably be low enough by 2025 to require operators to shut off power production that 29 million people depend on.

There are several reasons for the loss of power-generating capacity:  infilling of reservoirs with sediment, evaporation, and less water availability from melting snowpack due to climate change.  ATCO Power has stated that it wants to build a “run of the river” dam with minimal reservoir storage.  If there is a small reservoir then it also has the capacity to fill with sediment faster, especially since the Slave River has very high levels of suspended sediment, ranging from 3-5600 mg/L (AANDC, 2013).  After the dam is built, ATCO will probably have to build another dam upstream in order to capture the sediment to keep the hydro facility functioning at full capacity.

A river carries many things besides water, however.  A dam cannot be “run of the river” because it serves as an impoundment by which, not just water, but sediment, nutrients, and organisms cannot pass.  This blockage of the natural flux of materials up and downriver has devastating environmental effects; effectively contributing to species loss, decimating fisheries, and starving floodplain lands of much needed nutrients and water (Richter et al., 2010).  The  environmental impact that the W.A.C Bennett dam has had on the Athabasca delta upstream of the Slave River is well documented (Environment Canada, 2013) and strongly felt by residents of Fort Chipewyan (Northern Journal, Jan 22, 2013) .

Large Dams Are Economically Unsound

Although hydroelectricity is cheap to produce, dams are not cheap to build and costs to the average citizen are very high.  The Slave River project is estimated to cost ~$5-7 billion, taking at least ten years to get a return on the investment (Northern Journal, Jan 15, 2013).  Most large projects are backed by the government (you – the taxpayer) or, for developing countries, by the World Bank (Washington Post, May 8, 2013).   Most hydropower projects have overly optimistic benefit projections, since dams do not operate at full capacity due to declining availability of water, evaporation, environmental flow releases, sediment infilling, climate change and/or political situations.

Once you add in the cost of mitigating effects of the dam such as food scarcity, flooding, pollution, relocation, ecosystem rehabilitation, countering risks of natural disaster, and cleaning up disasters that do occur (paid for in suffering by those affected and monetarily by the taxpayers) the cost-benefit for the average citizen just doesn’t pan out.  China is now recognizing the real unplanned costs of building the $23 billion Three Gorges Dam lies in mitigating permanent social, ecological, and geological damage (Global Research, Feb 8, 2013).

The Future

I firmly believe that the way of the future and the solution to our energy woes lies in the next big thing in energy: decentralization (Roberts, Feb 26, 2013, Dolezal, Feb 6, 2012).  Decentralized, localized, diverse sourcing of energy avoids the waste of long transmission lines, is robust to failures of any one system, doesn’t damage the environment in irreparable ways, and will provide wider access to more people.  Large hydropower projects requiring big dams do not fit into this picture, but perhaps in-river turbines that don’t require a dam do (Eaton, Dec 23, 2008).

The argument doesn’t have to be about hydropower or no hydropower; it should rather be about what kind of hydropower.  The Slave River may be a perfect location to install a series of in-river turbines as a part of the renewable and clean energy plan for Canada.

In response to Chief Cheyeanne Paulette citing environmental reasons for not allowing feasibility studies to continue in 2010, one supporter of the Slave River Hydropower dam wrote [you] “live in the stone age, paulette [sic], you hypocrite!” (CBCnews, Oct 18, 2010). Big dams were originally built in ignorance of their widespread consequences.  They are a vestige of the Industrial Age.

It is time that we moved forward and start considering solutions to our problems fitting of the Information Age. We have the information, now let’s act responsibly.  If you clogged most of your arteries in your body, you would no longer be able to live.  Likewise, if we keep clogging the rivers of the Earth, don’t be so sure that this planet will be able to support life as we know it.  The current spurt of damming of large rivers in the name of obtaining renewable clean energy is a global crisis.  I plead for the sake of humanity: let’s stop staunching the flow of our rivers and choose to live.

Map of all large dams in the World from the GRanD database.

Natalie Anderson has received support for her work on Mackenzie River driftwood from the National Geographic Society. She is also a Sustainability Leadership Fellow with Colorado State University’s School of Global Environmental Sustainability (SoGES). View the program’s blog, HumanNature

Note: All views are those of the author, and not necessarily National Geographic.

About National Geographic Society

The National Geographic Society is a global nonprofit organization that uses the power of science, exploration, education and storytelling to illuminate and protect the wonder of our world. Since 1888, National Geographic has pushed the boundaries of exploration, investing in bold people and transformative ideas, providing more than 14,000 grants for work across all seven continents, reaching 3 million students each year through education offerings, and engaging audiences around the globe through signature experiences, stories and content. To learn more, visit or follow us on Instagram, Twitter and Facebook.