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Why We Need Dams — and a Sustainable Path Forward

This week Conservation International staff are converging in Sweden at World Water Week, one of the biggest international water conferences. We’re speaking, organizing sessions and workshops, and meeting with decision-makers from all over the world. Much of the discussion is focused on dams — or, more correctly, water infrastructure.

Why? The simple reason is that we cannot talk about conservation or sustainable development without also talking about where to locate, how to build and how to operate dams.

As part of my current internship with Conservation International and the Alliance for Global Water Adaptation, I have been spending many hours researching dams. It came as no surprise to find that the answers to the questions above are quite complex.

Traditionally, conservation groups simply said “no” to building dams due to their high environmental cost. Indeed, sedimentation, habitat loss and other side effects of dams have caused freshwater ecosystems and species to decline at a faster rate over the past century than any other category of ecosystem, including forests and oceans. In addition, dam construction has been responsible for the eviction of numerous indigenous and traditional communities from their homelands.

However, the strategy of fighting dam development hasn’t worked very well. With over 48,000 large dams exceeding 15 meters (over 49 feet) in operation worldwide, saying “no” to all dam construction is not a realistic solution.

Arguably, dams are one of the reasons that the United States and other developed nations have achieved so much economic success. Irrigation, farming, fishing, energy production, recreation and drinking water all depend on functioning dams. Meanwhile, large dams are being built at an incredible rate in developing countries, especially China and India; these countries also need regular water usage for cities, food and energy.

These numbers say it all:

  • The total number of dams globally is over 845,000 according to a Discover Magazine article.
  • The U.S. currently has 87,359 dams according to the U.S. Army Corps of Engineers National Inventory of Dams.
  • As of early 2013, China alone has more than 5,191 large dams over 15 meters high. Of those, over 117 massive dams greater than 60 meters (about 200 feet) have been completed or were under construction prior to 2006, according to Dr. Jia of the International Session of Hydropower.
  • The Mekong River in Southeast Asia is another area where pressure is increasing for additional, rapid dam development. On the Mekong there are several dozen dams newly in operation or under construction, and more than 85 new dams have been proposed. The massive Xayaburi Dam (the first of 12 dams proposed for the Lower Mekong) has served as a catalyst for more dam construction on the lower portion of the river. (Learn more about the status of dams on the Mekong.)

Rather than rejecting all dams outright, a better approach may be to ask, “When we need to build a dam, can we make it better for the environment?”

One study (PDF–3.92 MB) suggested that losses from droughts in countries such as Ethiopia reduced economic growth over more than a decade — effects we can mostly avoid or reduce in the U.S. by building dams in better locations or by more fairly distributing water. In fact, the construction of large dams has nearly stopped in the United States, reflecting new environmental regulations (such as the Endangered Species Act) and increased understanding about how much dams have affected our ecosystems.

Conservation International is working hard on multiple fronts to ensure that ecosystems and livelihoods are included in how governments, investors and companies think about dams and water management. Lina Barrera’s blog on managing shared water resources explains some of what Conservation International is doing in the policy realm; Leonardo Sáenz’s recent post examined the connection between healthy cloud forests and dam productivity.

So where does that leave us? Until recently I wasn’t sure how to depict the best path forward. I have learned a good deal about climate adaptation in the short time I’ve been interning with Conservation International and AGWA, but still couldn’t figure out how to sum up this piece.

Then I came across a presentation given by Casey Brown of the University of Massachusetts. He sums it up quite nicely by saying, “Decisions are deterministic, but water management is something that can be flexible and adaptable to our changing climate conditions. This involves monitoring (understanding the current state of a system), options (incorporating flexibility in the design), and decision support (using the appropriate information to respond to changes in a system).”

We need a process for decision-making in the face of climate uncertainty. Shifting weather patterns are predicted to greatly affect precipitation in many parts of the world. Some areas will become drier while others will see an increase in precipitation events. These changes will have untold consequences for the freshwater supply of the people living there. Decisions in water management planning must take this into account. After all, dams are built to last, but the times, they are a-changing.

For millennia, fresh water has connected species — including people — with their environment and each other. Examples are everywhere. On the African savanna, animals gather around water holes. Many major cities were built on the banks of rivers.

When it comes to development, water is also a connector, bringing together a vision of sustainable water management that includes species, livelihoods — even gender. Dams are just one piece of this puzzle, but they are a piece we can’t leave out.

Alex Mauroner is an intern in Conservation International’s Center for Environment and Peace. His internship is supported by the Trott Foundation.