The removal of aging infrastructure through silted-in dams has sparked a new way of thinking for the dams that may take their place
By Rich Svindland
Prudent investing in infrastructure also means removing obsolete assets. I had the privilege of working on the removal of the San Clemente Dam on the Carmel River near Monterey, Calif. This was a unique public-private partnership between my company and the State and Federal government, which resulted in the removal of a silted in, seismically unsafe dam. It restored Steelhead fish passage and ultimately included the donation of over 900 acres to the public. Many see this project as a model for dealing with aging infrastructure.
There are other dam removals expected to occur in the west. Plans are underway to remove the Matilija Dam in Ventura County, Calif., which, like San Clemente, has silted up and poses a risk to Steelhead. Four hydroelectric dams along the Klamath River in Oregon are also slotted for removal, making it the largest dam removal project in U.S. history once completed. Its deconstruction is expected to be complete in 2020.
We now must consider both a dam’s beginning and end along a much wider set of considerations that include a greater emphasis on sustainability and restoration.
These cases and others represent a shift in how the U.S. sees aging infrastructure. No longer are major infrastructure projects like dams, bridges, and railways seen solely through the lens of their utility. The environmental impacts of these structures, along with other externalities, are now considered as primary factors in their development and removal.
Many dams throughout California play important roles for water storage and flood control that can’t be realistically replaced with an alternative. In addition, the expected rise in global temperature will likely adversely impact the state’s Sierra snowpack – a key source of water. Alternatives will have to be developed to make up for the anticipated loss of storage and those will almost certainly include dams.
Yet, all dams have a life cycle. Every dam begins to fill with sediment over time and will eventually lose its storage capacity. In this new paradigm, we now must consider both a dam’s beginning and end along a much wider set of considerations that include a greater emphasis on sustainability and restoration.
In many ways, the San Clemente Dam presents a perfect case study of these changing attitudes and considerations. Built in 1921, the dam slowly filled with sediment over time, reducing its storage capacity to just 10 percent by the 1990s, when it was found to be seismically unsafe. As the dam’s owner, we at California America Water, weighed its options. The initial plan was to simply address the seismic and overtopping concerns by buttressing the dam. However, this solution would still leave a dam in place that served little purpose while still posing as a major impediment to the listed threatened steelhead, whose numbers had declined dramatically during the dam’s operation.
A number of federal and state agencies, including the National Marines Fisheries Service and the California State Coastal Conservancy, began to explore options on removing the dam altogether. The main sticking point was how to address all the sediment left over from the dam’s removal. Eventually, it was California American Water’s longtime dam keeper who floated the idea of leaving most of the sediment on site and rerouting the river around the sediment through an adjoining watershed. This plan was eventually adopted. In 2015, after three years of intense work, the dam came down and the river was rerouted.
The old way of thinking may have been to simply buttress the dam and leave it in place. But for this project, we and our government partners had to think beyond our individual obligations. This involved thinking about and planning for the project’s long-term environmental, social, and recreational benefits. The real beauty of this project is that 15 years from now, a hiker will come by the site, and see no indication a dam was ever there.
All major infrastructure has a lifespan. This project highlights how a public-private partnership worked to replace an aging asset and hopefully provides a model for other agencies to follow as they consider retiring infrastructure that has reached the end of its useful life.
Rich Svindland is Director of Operations for American Water. He may be reached at firstname.lastname@example.org.