As dams come down in different parts of the world, exciting opportunities are opened to restore lost habitats and cultural sites sacred to indigenous peoples.
This post is part of a special National Geographic news series on global water issues.
By Mark Angelo
As a river advocate and paddler for several decades, I’ve seen many of my favorite rivers lost to the building of large dams.
In my youth, I saw the completion of the Glen Canyon Dam in Arizona that flooded one of the most impressive gorges in the United States. In later years, I participated in perhaps the very last raft trip down part of the Bio Bio River in Chile before the completion of the controversial Pangue Dam.
And today, new dams threaten fabled stretches of the Coruh River in Turkey and the “great bend” of the Yangtze in China, both of which I’ve thoroughly enjoyed as a rafter and kayaker.
Horseshoe bend of the Colorado River just below the Glen Canyon Dam.
Photo by Mark Angelo
But while the specter of new dams continues to haunt many rivers, the decommissioning or dismantling of older dams that have outlived their usefulness, or provide only marginal benefit, is creating some exciting habitat restoration opportunities.
A good case in point can be found along the Clark Fork River near Missoula, Montana, where the Milltown Dam was removed in recent years. This represented one of the most extensive river restoration initiatives ever undertaken and, from a personal perspective, to see this unfold was especially heartening.
Mark Angelo in front of Milltown Dam prior to dismantling.
Photo by Danny Catt.
The beginning of the removal of the Milltown Dam.
Photo by Mark Angelo
I came to know the Milltown Dam well in the late 1960s while I was a student (and budding fly fishing enthusiast) at the University of Montana.
During my years there, I spent many wonderful days fishing and exploring nearby streams. But I quickly learned that the stretch of the Clark Fork above the dam was lifeless, decimated by the accumulation of mine tailings containing arsenic, cadmium, copper, and lead, among other metals.
All of these contaminants originated from more than a century of mining and smelting in the towns of Butte and Anaconda, located more than a hundred miles upstream.
Large Accumulation of Arsenic
In 1981, as a result of these pollutants settling behind the dam, nearby residents were informed that large quantities of arsenic had accumulated in the groundwater they drew from local wells.
In 1996 a large ice jam came close to breaking the dam. This necessitated an emergency release of both water and toxic sediments, resulting in a significant fish kill downstream.
To many locals, this was the straw that broke the camel’s back and a major community movement was launched to decommission the dam and clean up the river.
After a lengthy struggle, work to dismantle the dam and remove more than six million cubic yards of toxic mud commenced in 2005. Today, the river runs free for the first time in more than a hundred years. Fish can once again migrate freely and efforts are underway to restore cutthroat and bull trout populations.
Ultimate in River Restoration
Projects like this represent the ultimate in river restoration, and I’m encouraged by the growing list of similar examples found elsewhere.
For instance, in my own province of British Columbia, Canada, BC Hydro decommissioned the Coursier Dam several years ago near the town of Revolstoke. This was done primarily for safety reasons, but the dam’s removal enabled both the outlet and upper reaches of Cranberry Creek to be restored.
This proved to be a great success and the stream is now heavily used by native rainbow trout.
And in eastern Canada in the province of New Brunswick, the opening of the gates of the Eel River Dam this past summer was greeted with great fanfare and excitement.
This dam has stood at the mouth of the river for 47 years and local First Nations have long viewed its construction as an assault on their community and the environment.
The dam will now be completely removed in 2011, setting the stage for renewed fish passage.
In addition, plans call for the re-establishment of salt marsh wetlands and the restoration of habitat for soft-shelled clams and other shellfish.
And not too far to the south from where I live, one of the world’s most exciting dam-removal initiatives is set to unfold on the Elwha River located in Washington state’s Olympic Peninsula.
Photo of Elwha Dam by Mark Angelo
In the early 1900s the Elwha was renowned for its fishery and, in particular, its massive chinook salmon, which were affectionately known as “June Hogs”. Weighing as much as 90 pounds (40 kilograms), these massive fish could be taller than most adults when stood on end. A century ago they numbered close to 400,000 fish; runs were so huge, the river became “a wiggling mass from bank to bank.”
But after the first Elwha dam was built in 1913 (followed by a second dam in 1927), salmon stocks plummeted. Today only a remnant run remains, totaling 2,000-3,000 fish, and yet river advocates are optimistic that salmon stocks will rebound once the dams come down.
Having visited the area several times, I agree that the chances of success are high. Most of the river habitat remains in good shape, much of it being in Olympic National Park.
Plans also call for the dams to be removed gradually over a three-year period, enabling much of the accumulated silt to be gradually flushed downstream. Total cost of the project is expected to be close to U.S.$300 million, including both dam-removal and the restoration of the salmon run.
While never seeing the “June Hogs” that the Elwha was so famous for, I’ve spent a lot of time on BC’s Harrison River, which is also renowned for a run of exceptionally large chinook reaching 30 kilograms (66 pounds) and more. I have long been amazed by these fish–so the even larger size of the Elwha chinook must have been an astounding thing to see.
Mark Angelo (foreground) and BCIT colleague with midsize Harrison chinook (spring) salmon. Elwha fish were historically bigger.
Photo by Danny Catt
But while the removal of the dams on the Elwha presents a great opportunity to rebuild the fishery and restore an aquatic ecosystem, there will be other benefits.
For example, there will be numerous cultural spin-offs in that the building of these dams flooded the only inland village of the Elwha-Klallam First Nation. According to tribal legend, this is where the Elwha-Klallam were created–so needless to say, the removal of the dams has garnered great support from indigenous communities.
Looking elsewhere, there have been many other exciting dam-decommissioning projects that have unfolded, ranging from the Loire River in France to the removal of the Marmot and Savage Rapids dams in Oregon. There is also an active movement, led by the Glen Canyon Institute, that is making an effective case for the removal of the Glen Canyon Dam in Arizona.
Having witnessed the completion of this dam as a boy (and having often departed from its downstream side when setting off to paddle through the Grand Canyon), I find it exciting to think I may possibly see this dam removed within my lifetime.
And finally, coming back to the site of the old Milltown Dam, I clearly remember wondering as a young man what this part of the Clark Fork River might have been like to paddle and fish before the dam was built. I now look forward to returning and finding out!
Photo courtesy of Mark Angelo
Mark Angelo (above) is the chair of the Rivers Institute at the British Columbia Institute of Technology and an internationally acclaimed river conservationist. He has received the Order of Canada, his country’s highest honor, in recognition of his river conservation efforts both at home and abroad. He received the United Nations International Year of Fresh Water Science, Education and Conservation Award, the Order of British Columbia, the National River Conservation Award, and an honorary doctorate from Simon Fraser University. He is a Fellow International of the Explorers Club. Angelo is the chair and founder of World Rivers Day, an event celebrated across dozens of countries on the last Sunday of each September. He has traveled on and along close to 1,000 rivers around the world over the past 5 decades. He has authored numerous articles and papers about rivers and his expeditions, including the Riverworld presentation launched in concert with National Geographic Online in 2003 and shown to audiences across North America.
The views expressed in this article are those of Mark Angelo and not necessarily those of the National Geographic Society. Read more blog posts by Mark Angelo.
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