Current Events: Dam Removals

Since the earliest human civilizations dams have been used as means of energy generation, flood control, and irrigation. Dams are built on rivers so that the water in the river can be controlled. Nearly two out of three major rivers in the world have been stoppered at one place or time. In most cases, dam installation floods the valleys upstream of the dam, displacing populations of humans, and creating an artificial lake, known as a reservoir. Reservoirs have enabled civilizations to thrive in otherwise arid regions, giving humans control over the flow and distribution of the water.

However, these barriers also fragment water ecosystems, stopping the movement of species and exchange of nutrients as some organisms and sediment are trapped in the reservoir while others are stuck downstream. Salmon, in particular, are unable to migrate back upstream to their spawning waters without the installation of fish ladders and are in severe decline, as are the species that depend on them. Also, in times of drought, downstream flows released from dams are insufficient to maintain aquatic species since water temperatures rise, stressing fish and causing algae blooms.

As water becomes more scarce, competition between multiple users puts pressure on policy makers to balance all these interests. In the last twenty or so years, public pressure to remove dams and restore river flows has been gaining traction. Public pressure combined with expensive operating costs have invited discussions around the long term viability of creating and maintaining dams. While the 20th Century was an era of dam construction, global trends are now reversing. Dams are coming down. A confluence of factors have brought about this new trend. First, many areas are experiencing lower water flows as the climate warms, reducing the amount of electricity generated by each dam while other power sources are becoming more economical. Secondly, as dams age, the sedimentation behind them builds up and diminishes water storage capacity, requiring more attention and costly maintenance. Third, dams can fail, like the Oroville Dam in California, which required over a billion dollars to repair. In some cases, dam maintenance often proves more costly than removal. Finally, in many places, like the Pacific Northwest of the USA, native tribes are exercising legal treaty rights to restore river flows and fish populations throughout the region.

This week’s Current Events resources examines the history and impact of dams. The resources shared provide information and context around dams’ controversies, impacts, and the world’s largest dam removal and river restoration project happening on the Klamath River.

Essential Questions:

What were the unintended consequences of damming rivers?
What have the various interested parties in damming rivers, and their key priorities?
In regard to river management policies, what responsibilities and concerns overlap amongst various governments?
What are the roles of pre-existing treaties during the policy decision making process for governments?
What are the advantages and disadvantages of dam removals?
In your opinion, what, if any considerations should hold the most weight when governments determine water management policies?