How California Utilized A P3 To Restore A River

In California, an intersector partnership began demolishing the 94-year-old San Clemente Dam in an effort to restore the Carmel River

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By Mary Velan

Gov1

What Happened?

In California, an intersector partnership began demolishing the 94-year-old San Clemente Dam in an effort to restore the Carmel River. The public-private partnership is made up of local, state and federal government agencies, environmental nonprofits and a water company.

Goal

The San Clemente Dam Removal Project is the largest dam removal project in California to date. The goal of the project is to remove the outdated dam and restore the Carmel River. The watershed restoration initiative is designed to:

  • Provide a long-term solution to the public safety risk posed by the potential collapse of the San Clemente Dam. Currently 1,500 homes and public buildings are in danger in the event of a large flood or earthquake
  • Provide unimpaired access to over 25 miles of essential spawning and rearing habitat to aid in the recovery of the threatened South-Central California Coast steelhead
  • Restore the river’s natural sediment flow, helping replenish the Carmel Beach ecosystem and improve habitat downstream
  • Reduce beach erosion that contributes to destabilization of homes, roads and infrastructure
  • Re-establish a healthy connection between the lower Carmel River and the watershed above the dam
  • Improve habitat for threatened California red-legged frogs

Not only will the dam removal and river restoration project increase access of several species to new habitat, but also create more green space for residents to enjoy. Roughly 928 acres surrounding the watershed will be managed by the Bureau of Land Management for the purpose of outdoor recreational activities.

Process

The San Clemente Dam has accumulated 2.5 million cubic yards of sediment over time, which can neither be trucked out or allowed to flow downstream due to the massive quantity. The P3 hopes to set a precedent in dam removal projects through its unique approach to the process. The project design involves an innovative engineering approach to re-route a half-mile portion of the Carmel River into San Clemente Creek. The abandoned reach will then be used as a sediment storage area. The design minimizes the amount of sediment that must be gathered and removed. This will reduce project costs and mitigate several environmental impacts.

The dam removal project is estimated to cost $84 million total. Funding for the project is coming from three sources: the California American Water Company, public and private sources such as federal and state funds and nonprofit donations. The California American Water Company owns the dam and will contribute $49 million to the removal project. The company will generate these funds by raising rates for water customers in Monterey County by an average of $2.55 a month over the next 20 years, KSBW reported.

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