Figure 1: Hoover Dam at night in Black Canyon on the Colorado River between Nevada and Arizona
Among the throng of pressing matters our generation, and those to come, must address stands a daunting figure; the energy question hand-in-hand with its potentially divorceable question of climate change. In attempts to satisfy the former while dispelling the latter, nations have turned their eyes to the concept of renewable energy, renewable in reference to its ability to be reproduced indefinitely with proper management. As of 2015, renewable energy composed 20% of the global profile, with 80% of that energy captured from water resources through the construction of dams. That 80% of the current global renewable energy produced composes only roughly 22% of the total “technically feasible hydropower potential” of upwards of 15.6 million GWh per year (Zarfl et al., 2015). Under the Rio+20 targets for countries to meet energy needs through Kyoto-compliant energy resources, the large amount of potentially harvestable energy would excite any nation toward the construction of more dams to tap into the reserves. In accord, however, with the modern evolution of the engineering field, the question is not, “can we…?” but “should we…?” A little investigation into conventional hydropower production and its implications reveal staunch “inconveniences” to that effect…
Figure 2: the explosion of the Dam Boom currently in progress
Figure 3: Geospatial dispersion of future dams
Dams produce their power through channeling water into conduits leading to turbines which capture the energy and convert it to electricity. A viable gradient is created by blocking the flow, forming reservoirs of much greater height so that the channeling of water to the downstream portion would produce more energy.
Figure 4: Diagram of harnessing hydropower
Figure 5: Generators fed by turbines at the Hoover Dam
The construction of a dam, however, cripples the viability of a watershed and its streams to perform the role they have in supporting life through social, cultural, ecological, and economic wounds. Ecologically, dams disrupt the flow of water, leading not only to lower flows downstream, but lower temperatures and dissolved oxygen content as well. As for natural flow regimes, widely fluctuating patterns may be hampered by a more static flow regime from a dam while patterns that are typically steady may be suddenly changed by less static dam regimes. The formation of the reservoir not only displaces people from their homes, and territorial grounds for tribes or other ethnic minorities, but deprives them of the way of life and resources that were theirs in their territory. Those losses are normally not compensated, and the displacement process verges on violations of human rights. The Three Gorges Dam in China’s Yangtze River represents vividly the huge costs of big dam construction, yet its existence provided proof it could be done and has sadly encouraged China to spur on the coming forth of a Dam Boom throughout the world, despite the governments recent acknowledgement of all the problems the dam is now known to have caused.
Figure 6: Three Gorges Dam near Yichang, Hubei in China
In the United States, the problems of dams and other hydropower facilities are being addressed by Low Impact Hydropower Institute, which offers a Certificate Program to set apart facilities whose presence is low impact. They established 8 criteria to gauge a site;
- Ecological flow regimes that support healthy habitats
- Water quality supportive of fish and wildlife resources and human uses
- Safe, timely and effective upstream fish passage
- Safe, timely and effective downstream fish passage
- Protection, mitigation, and enhancement of the soils, vegetation, and ecosystem functions in the watershed
- Protection of threatened and endangered species
- Protection of impacts on cultural and historic resources
- Recreation access is provided without fee or charge
These criteria, once met, merit a certificate of approval for facilities under the authority of relevant state or federal resource agencies that protect the resources mentioned in each criterion. Each criterion has a specific goal statement, and alternative standards are created for each one to create a variety of ways various facilities, including dams, can be represented as low impact. This system allows sites to be recognized for their environmental mindfulness, and is often necessary for hydroelectric facilities to receive eligibility in state Renewable Portfolio Standards (RPS). The system, however, does not address the social or cultural/historical wounds inflicted by the construction of such facilities.
International Rivers, a watchdog of global freshwater corridors and the people groups who depend on them, keep close watch over the impacts of dams constructed and place the stories from remote corners onto the global stage. Their articles and stories raise the hard and fast questions of our approach to the vast reservoirs of hydroelectric potential on the planet. For example, the Brazilian government has been trying to push construction of dams in the Amazon River Basin for years. In 2008, they were held off from construction of such dams in the Xingu River by the protesting of hundreds of indigenous people groups from all corners of the Amazon Basin. Several tribes sent representatives donning ceremonial garb and paint, performing rituals not typically seen outside the village, and advocating for their peoples’ needs in light of the potential projects. For them, their protests were a success, but for others the same can not be said.
How can we address the Global Dam Boom displacing millions worldwide while also disrupting the natural systems in our watersheds? Is it right to sacrifice the good of some for the good of many? Are there other ways hydroelectric power can be produced?