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Letting the Rivers Run: An Interview With Sandra Postel

Last month, the U.S. Secretary of the Interior joined the governors of Oregon and California, the CEO of electric utility PacificCorp, and the chairmen of the Klamath, Yurok, and Karuk tribes to announce agreements that pave the way for removal of four large dams on the Klamath River by 2020.

If ultimately enacted, the plans would open a 300-plus-mile migratory route to spawning grounds for endangered Pacific salmon. The agreements also cover the distribution of Klamath Basin water between farmers and ecosystems that support both fish and the fishermen who catch them. Dispute over the fate of the Klamath’s water dates back a century.

(See the December 2008 National Geographic magazine article “Klamath River” for background on the conflict.)

Global Water Policy Institute director and National Geographic Fellow Sandra Postel joined me to discuss the costs and benefits of taking down dams.

Why did some want to remove dams from the Klamath, and what makes the decision so consequential?

First, it’s important to acknowledge that many dams serve important purposes for the country that surrounds them, for the economy. They provide hydroelectric power, flood control, a drinking water supply, irrigation water, and places for recreation. So they’ve been built for a reason, to provide these benefits.

At the time most dams were built, concern about river ecosystems wasn’t high on the radar screen. Now that we understand more about how dams can affect ecosystems–the life within rivers–we understand that they have a serious downside.

In the case of the Klamath, it’s a great example of how various uses for the river came into conflict: Native American interests, fisheries’ interests, farmers’ interests, the desire for hydroelectric power. And then there were the beautiful salmon runs. The four dams slated to come down under these agreements brought all the conflicts over water’s uses to a head.

What’s planned for the Klamath is perhaps the biggest river restoration project in the U.S. to date, so it’s historic. It’s also remarkable so many disparate groups came together and reached an agreement that seems like it’s got a lot of win-wins attached to it.

One of the wins: It will open up more than 300 miles of habitat for salmon, and that has significant ecological value, since salmon on the Pacific have become so endangered.

Does the Klamath decision reflect a trend?

I would say it does. The story is similar across the U.S.: We hadn’t fully considered the ecosystem consequences when dams were built. We’ve seen about 430 dams removed over the last ten years–most of them smaller than 15 feet.

They’re coming down for two reasons. One is safety: They’re old, as with the 19th-century dams for textile mills in New England. If they’re not maintained, they can cause problems downstream with flooding. One of the historic moments on this sort of dam was in 1999, when the Edwards Dam came down on the Kennebec River in Maine.

The Kennebec is a large and beautiful river system that drains much of Maine. A private hydropower dam on the river blocked American shad, alewife, a bunch of different Atlantic species–four or five in all. A federal commission took a look at it when it came up for renewal. It produced a small bit of hydropower for Augusta, Maine, but it wasn’t worth the dam’s ecosystem downsides and effects on fisheries. It wasn’t serving enough of a useful purpose.

It was a big deal when the Kennebec dam came down. Bruce Babbitt (then U.S. Secretary of the Interior) said this was a new day for dams. Today, companies and agencies responsible for dams have to demonstrate that they serve a useful social purpose when they come up for permit renewal.

There’s one other issue with dams that I think is potentially more important: Big dams cause changes in the flow patterns of rivers, when they run high and low.

We’re not going to take a lot of the largest dams down, but you can incorporate ecosystem concerns and knowledge into how these dams are managed. You can time the release of water so that fish have cues to come upstream and spawn, so you get both fisheries benefits and flood plain protection.

How many dams does the federal government manage in the U.S.?

There are 1,932 federal dams that taxpayers continue to pay for. The Army Corps of Engineers is responsible for some, the Bureau of Reclamation, the Tennessee Valley Authority in the southeast, Bonneville Power in the northwest.

Photo of Glen Canyon Dam, Arizona, by Walter Meayers Edwards


Are there specific dams in the U.S. that pose ecosystem concerns?

The four dams on the lower Snake River have been controversial for a long time. They’re extremely damaging to salmon runs. The issue of what to do with them is still very much under debate.

And outside the U.S.?

Yes, particularly in countries where dams are just getting built on rivers. China has about half the world’s large dams, and they’re building more at a gangbuster rate. Their economy’s growing at 10 to 20 percent per year, and they need a lot of energy. They’re burning coal for much of it, but they’re still building a lot of dams.

Right now, they’re building dams in the headwaters of the Mekong, which will affect the whole flow downstream. That in turn affects perhaps the most abundant fishery in the world. The flow regime there supports an incredible amount of biodiversity and fisheries production.

China is also one of the few countries that hasn’t subscribed to the idea that you need to share transboundary waters in some equitable way. It has declined to sign an international accord on this, as have Turkey and Burundi.

China and Turkey are both upstream countries, home to the headwaters of major rivers. In effect, they’re saying this is our water to do with what we want to do. There are all kinds of ramifications to that stance. Meanwhile, Turkey’s trying to develop a very poor region agriculturally and economically with Euphrates waters that historically flowed downstream to Syria.

They’re doing what we did here in the U.S. After we built Hoover dam (the first of the large dams on the Colorado River, creating Lake Mead) and changed the historic possibilities with rivers, we exported dam technology abroad.

Given what we know today, how do you think we should be managing our rivers?

The challenge used to be how to control rivers. Rather than work against the natural regime, if people work with it–go with the flow–both people and ecosystems are better off.

When you think about the relationship of rivers to floodplains, you get natural water recharge, replenished soil. We go out and build levies, build water purification plants. All of that stuff takes energy, replacing natural services powered by free solar energy. And the value of natural ecosystem services keeps going up as the replacement cost goes up.

There are good examples of communities that are starting to get this, and doing something about it. One is the Napa River. It’s flooded some 19 times in the last couple decades. Finally, they decided we’re not going to push the flooding away any more. They removed a few businesses and homes and are beginning to let the river use its floodplain again, rather than take the “straighten it and levy it” approach.

It looks as if this is going to be a very beneficial change for Napa. They’ve got lovely new foot trails, and it’s reconnected the community to the river. The riverside cafés have a beautiful river to enjoy, instead of levies. Homeowners’ and businesses’ flood insurance rates have gone down. Now people from outside the country are coming to see what’s been done at Napa.


Sandra Postel is a contributor to the new National Geographic book Written in Water: Messages of Hope for Earth’s Most Precious Resource, a collection of firsthand accounts of efforts to bring clean water to all. Learn more about freshwater resources, habitats, and challenges from National Geographic.

Ford Cochran directs Mission Programs online for National Geographic. He has written for National Geographic magazine and NG Books, and edits BlogWild–a digest of Society exploration, research, and events–and the Ocean Now blog. Ford studied English literature at the College of William and Mary and biogeochemistry at Harvard and Yale, with a focus on volcanoes, forests, and long-term controls on atmospheric CO2. He was an assistant professor of geology and environmental science at the University of Kentucky before joining the National Geographic staff.

More posts by Ford Cochran

[This post has been reformatted for Water Currents.]


  1. endangered farmer
    April 10, 2010, 12:10 am

    It will forever amaze me that all the historical proof concerning the Klamath River gets ignored by those who desire to “restore” the river. The Klamath River has always been plagued with extremely poor water quality beginning with the the earliest explorers way before farmers, dams or any settlements of any kind, except the native americans. The water was so bad, the first explorers would not camp near the smelly, bug infested water. The livestock could not even drink the water. You see, the real science in our basin proves that the volcanic soils add natural occuring phosphorus to the water in the shallow Klamath Lake that is naturally warm, which produces the algae, which in turn produces nitrogen. So if you want to critize the water quality, you have to be critical of MOTHER NATURE, not farmers, cities or dams. The so called massive fish runs were only sporadic at best. In fact the largest fish runs on the Klamath River actually occured after the dams were in place. Go figure!!