Addressing Aging Infrastructure

The Carmel River Reroute and San Clemente Dam Removal project highlights how a public-private partnership worked to solve an aging infrastructure problem

By Sergio Flores

Public scandals have highlighted our aging infrastructure and the dire need to either update or completely replace them, but how to fund them remains a problem. Because infrastructure is an investment that pays for itself in the long-run, more and more private organizations are partnering with government to provide a means to fix our nation’s crumbling infrastructure. Not all infrastructure can be easily updated, though. As our nation moves towards the future and builds infrastructure meant to last decades, much of our nation’s infrastructure assets are past their life-cycles and need to be removed completely.

A paragon example of how to deal with aging infrastructure is California American Water’s removal of the San Clemente Dam on the Carmel River near Monterey, Calif. California American Water partnered with the State and Federal government to address the aged dam. The project’s environmental endeavors have garnered the attention of our readers, voting this project as American Infrastructure magazine’s Green Project of the Year for 2016.

Built in 1921, the San Clemente Dam featured a 106-foot-tall concrete arch dam. Over time, though, the dam began to slowly fill with sediment, and by the 1990s many problems faced the dam: sediment reduced the dam’s storage capacity to just 10 percent by the 1990s; after it was noted that the dam was subject to overtopping in a historically significant rain event to occur in the watershed, the dam was also deemed to be seismically unsafe; and when the south-central coast steelhead became listed as a threatened species, environmental issues were of the utmost concern. But what was the dam’s solution? Upgrade? Modernize? Or completely remove?

“As the dam’s owner, we at California America Water weighed its options,” said Rich Svindland, Caliofornia American Water’s Director of Operations. He continued, “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 posing a major impediment to a listed species, whose numbers had declined dramatically during the dam’s operation.”

Removal became the obvious solution. Removing the silted in, seismically unsafe dam restored steelhead passage, opened up 25 miles of additional steelhead spawning areas, and included the donation of more than 900 acres of land to the federal government—and eventually the land will be open to the public.

Svindland notes, “This project illustrates how new approaches can solve complex infrastructure problems while providing environmentally beneficial outcomes.”

A number of federal and state agencies, including the National Marines Fisheries Service and the California State Coastal Conservancy began to plan for removing the dam altogether. The main issue that needed to be addressed was what to do with all the sediment behind the dam – where would it go?  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.

 

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