The Dam Truth - Waterkeeper

The Dam Truth

By: Gary Wockner


From Oroville to Hoover Dam – Seven Reasons Why Climate Change Will Undermine Dams and Reservoirs as a Source of Water and Electricity

Ten years ago I was pictured on the front page of the Fort Collins Coloradoan newspaper giving a presentation titled, “The Dam Truth.” The movie, “The Inconvenient Truth,” had just come out and I thought “The Dam Truth” was a plucky spinoff that would grab the public and media’s attention, which it did. Our local Waterkeeper in Fort Collins – Save The Poudre: Poudre Waterkeeper – has been fighting, and continues to fight, a massive dam project on the Cache la Poudre River that inspired this presentation and much more.

Image: April 8, 2008, Fort Collins Coloradoan.

As I write this on Sunday, February 18th, 2017, the investment company, The Motley Fool, just posted a blog titled: “Why Wind and Solar May Have to Fill In for America’s Crumbling Hydro Infrastructure.” And yesterday, a team of advocates from Friends of the River in California posted a column in the San Francisco Chronicle titled, “To Avoid Catastrophe, Don’t Build More Dams.” Further, Grist borrowed my 2008 presentation title with a blog three days ago titled, “The Dam Truth: Climate Change Means More Lake Orovilles.”

These stories – and dozens more in the last week – were focused on and caused by the looming catastrophe in Oroville, California, where the U.S.’ tallest dam teeters on the brink of failing. The engineering flaws at the Oroville Dam have been exposed by the incessant rains in northern California.

But these engineering flaws are only the tip of the iceberg of why dams should be abandoned as a water and electricity source in a climate-changed world.

  1. Extreme Weather Variability: Extreme weather events are more common and variable in a climate-changed world – intense droughts have emptied reservoirs, followed by extreme rains and flooding that have overwhelmed dams and reservoirs. Scientist tell us to expect more of both as the climate warms. Many dams and reservoirs have been built to “100-year flood and drought” standards. If 500-year or 1,000-year floods and droughts become commonplace, Oroville-like disasters will too.
  2. Methane Emissions: The runoff of vegetation and organic matter into reservoirs decomposes and emits methane. Sometimes, hydroelectric dams emit more greenhouse gas emissions from methane than the equivalent CO2 emissions from a coal-fired powerplant. In fact, Hoover Dam on the Colorado River – which supplies electricity to much of Southern California – has been estimated to emit as much greenhouse gases as a coal-fired powerplant.
  3. Evaporation: Many reservoirs – especially in warmer and dryer climates – evaporate massive amounts of water that could otherwise be used for human consumption and ecological needs. On the Colorado River, for example, over 10% of the entire flow of the river evaporates in the giant reservoirs of Lakes Mead and Powell. Scientists predict that the Southwest U.S. will get hotter and dry out more, leading to even more evaporation and less water in the river and reservoirs. Worldwide, a recent report from the United Nations estimated that reservoirs evaporate more water than humans consume across the planet.
  4. Blocked Sediment: Sediment – sand, dirt, organic and inorganic material – gets trapped behind a dam, no longer flows to the ocean, and starves coastal wetlands, beaches, and reefs. The increasing lack of sediment and diminished beaches and wetlands increases the impacts of storm surges and sea level rise in coastal communities.
  5. Submerged Landscapes Block Carbon Sequestration: US reservoirs associated with the country’s two million dams have submerged millions of acres of previously carbon sequestering grasslands, forests, and farmlands further escalating the greenhouse gas problem. The International Panel on Climate Change has identified the loss of forests and other carbon sequestering habitats as a major contributor to climate change because dams and their reservoirs have submerged and destroyed millions of acres of forests, grasslands, and farmlands worldwide.
  6. Increased Flooding Risk: Dams and reservoirs that divert water out of rivers cause those rivers and streams to become choked with vegetation, sediment and more narrow over time. When the inevitable flooding conditions occur – which will be more frequent in a climate changed world – the flooding is worse because the river channel can no longer contain the high flood flows.
  7. Imperiled Water Quality: Reservoirs absorb heat and therefore fuel toxic algae blooms and lethal conditions in the reservoirs and rivers upstream and downstream. As one of many examples, endangered species like Columbia and Snake River salmon are further imperiled and are often put in trucks and barges to be driven around these stagnant “dead pools” in reservoirs and rivers.
An aerial view of the damaged Oroville spillway in Oroville, Calif. (Photo: California Department Of Water Resources via European Pressphoto Agency)

The Motley Fool article nails it when they highlighted alternative stock picks that focus on wind and solar instead of dams and reservoirs from hydropower. And the Friends of the River column further highlights alternatives for how water can be served to cities and farms without using ultra-expensive, environmentally damaging, and increasingly risky dams and reservoirs.

In a climate-changed world, countries across the planet – including the U.S. — need to heed these alternatives now, rather than further invest in hydropower. If we don’t, we will continue to learn expensive, life-threatening lessons like those teetering on the brink in Oroville, California.

And that’s The Dam Truth.

Gary Wockner, PhD, directs Save The Poudre: Poudre Waterkeeper, The Save The Colorado River Campaign, and advocates and writes about protecting free-flowing rivers across the planet. Contact: [email protected]