Hydropower and Climate Change

Our nation is at a crossroads. We desperately need to reduce our dependence on fossil-fuels and decrease the amount of carbon in the atmosphere. That means that we need to use less energy, and we need to get more of our energy from renewable sources.

It is equally imperative that we do not destroy the environment we are trying to save by rushing to develop low-emissions energy sources that will result in serious environmental harm, as well as high economic and societal costs. We can have – and must demand – energy that avoids carbon emissions, does not consume finite natural resources, and does not irreparably harm the environment.

Hydropower dams will continue to play a role in our nation’s energy portfolio. But we cannot responsibly meet our nation’s 21st century energy needs by damming new rivers or by weakening environmental protections designed to protect rivers from harmful dam operations.

Hydropower solutions for the 21st century

American Rivers supports the continued operation of most hydropower projects. We have a long history of working with dam owners to improve the operations of projects, achieving successes for ratepayers, the economy, and the environment. We also advocate for the removal of outdated or unsafe dams whose costs outweigh their benefits.

The focus on hydropower in the coming years must not be on building new dams, but instead on maximizing efficiency, responsible operation, and environmental performance.

  • Increase efficiency at existing hydropower dams:Most of our nation’s hydropower dams were built 50, 75, even more than 100 years ago. Many of these dams use antiquated, inefficient generating equipment. Dam owners should be required to bring their plants up to modern standards in order to ensure that they are generating the maximum amount of power from every drop of water that they use.
  • Consider adding hydropower capacity to existing dams:There are more than 90,000 dams in the United States, and only a fraction of those dams have hydropower capacity. Adding hydropower to dams in good repair that are still serving another useful purpose is appropriate if it can be done without further degrading the local environment that is already compromised by the existence of the dam
  • Uphold environmental safeguards:If a hydropower dam can’t be operated economically while meeting modern environmental standards, then either its operations should be improved, or the dam should be removed. New hydropower added to existing dams must be able to comply with all existing environmental laws and regulations; if it cannot, then it should not be developed. There are plenty of other sources of renewable energy that can be operated at a profit without harming the environment.
  • Hold hydropower developers responsible for dam safety:The majority of our nation’s dams are in need of significant repairs. Would-be developers of hydropower on existing dams must take these costs into consideration and must be responsible for ensuring that these dams are safe and secure.
  • Recognize that dams have finite lifespans:  For a structure to be truly “green,” it must be built with its full life cycle in mind.  New or retrofitted dams must have a decommissioning strategy, including a set aside fund dedicated to restoring the river when the dam becomes obsolete. 
  • Judge dams on their impacts, not on their size:  Low-power dams (many of which are physically quite large, despite insistence by developers that they are “small”) harm streams in the same ways as dams that produce more power. Multiple low-power dams scattered on multiple streams add up to major environmental impacts that can be greater than that of a single large dam. The power provided by smaller-scale hydro is a drop in the bucket compared to our overall energy needs. Low-power hydro projects currently account for 40 percent of all hydropower dams, but generate less than 1 percent of the power.

Why new dams don’t make sense

  • All the good locations are already developed:The available number of potential hydropower dam sites is limited by geography, and in the United States, the most viable sites have already been developed or are off limits. The few sites that remain would provide only marginal power benefits, often at great environmental cost.
  • Healthy rivers are our “natural defense” against global warming impacts:We need healthy rivers and the clean water and natural flood protection benefits they provide, in order to be resilient against the droughts, floods, and waterborne diseases that will increase with global warming. Likewise, fish and wildlife will need healthy, free-flowing rivers more than ever if they are to survive in a warming world. Building dams destroys the natural defense system that healthy rivers give our communities.
  • Hydropower dams can contribute to global warming pollution:When a forest is cut down to make way for a dam and reservoir, those trees are no longer available to absorb the carbon dioxide added by fossil fuels. Further, decaying vegetation beneath the reservoirs can generate emissions, which can contribute to global warming.
  • Dams damage rivers: Dams disrupt flows, degrade water quality, block the movement of a river’s vital nutrients and sediment, destroy fish and wildlife habitat, impede migration of fish and other aquatic species, and eliminate recreational opportunities. Reservoirs slow and broaden rivers, making them warmer. The environmental, economic, and societal footprint of a dam and reservoir may extend well beyond the immediate area, impacting drinking water, recreation, fisheries, wildlife, and wastewater disposal.

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