Construction crews have begun work removing the San Clemente Dam in Carmel Valley, California, the largest removal project in the state to date.


Construction crews have begun work removing the San Clemente Dam in Carmel Valley, California, the largest removal project in the state to date.

Elected Officials, conservation groups and community leaders from across the state gathered to celebrate the groundbreaking last week in an event hosted by California American Water in partnership with the California State Coastal Conservancy, NOAA Fisheries and The Nature Conservancy.

"This project will be the largest dam removal in state history," said Rep. Sam Farr, D-California. "It marks the beginning of a new era for this river, its inhabitance and the community it benefits. The project itself also marks a new way forward in terms of public-private partnerships and working together to accomplish major infrastructure endeavors like this one. This model could be applied to other dams in the state that have exceeded their useful life."

"After years of hard work, it is an honor to join the project team and other dignitaries to celebrate the removal of the antiquated San Clemente Dam and restoration of the Carmel River Watershed," said state Sen. Bill Monning, D-Carmel

Since it was built in 1921, the San Clemente Dam has impacted people and nature along the Carmel River. As a result, once vibrant steelhead runs have dramatically decreased and lives and property below the dam are threatened with the possible collapse of the seismically unsafe structure.

The antiquated dam does not provide significant water storage for the community and given the state’s requirement the dam to be seismically safe, is more of a risk than a benefit. The reservoir is over 95% filled with more than 2.5 million cubic yards of sediment and a remaining water storage capacity of only about 70 acre-feet.

Bringing the dam removal project to fruition was made possible by a strong partnership between California American Water, the owners and operators of the dam, and the California State Coastal Conservancy and NOAA’s National Marine Fisheries Service. Additional federal, state and local agencies and elected officials at all levels played key roles in the project’s design, approval, and funding.

The estimated project construction cost is $83M. Of this, US$49M will be provided by California American Water and $34M will come from the State Coastal Conservancy and NOAA Fisheries. The conservancy will raise its portion of the funding from various public and private sources, including a $1M contribution from The Nature Conservancy.

The removal project includes an innovative engineering approach of rerouting the river around accumulated sediment.

"Our approach eliminates the cost and environmental impact of transporting the sediment to a different location, while also avoiding increased flood risk for downstream property owners," said California American Water President and Chief Operating Officer Walter Lynch.

Granite Construction was selected through a competitive procurement process to design and build the three-year construction project. Granite will also perform five years of post-construction monitoring and maintenance activities to ensure that the project objectives are met and the restoration project is successful.

Removing the San Clemente Dam and restoring the Carmel’s nature flow will have many benefits including:
– Permanently removes the public safety risk posed by the potential collapse of the outdated San Clemente Dam, which now threatens 1,500 homes and other public buildings in the event of a large flood or earthquake.

• Aides in the recovery of threatened South-Central California Coast steelhead by providing unimpaired access to over 25 miles of essential spawning and rearing habitat.
• Expands public recreation by preserving over 900 acres of coastal watershed lands, resulting in over 5,400 acres of contiguous regional park land for low impact recreation.
• Restores the river’s natural sediment flow, helping replenish sand on Carmel Beach and improve habitat downstream of the dam for steelhead.
• Reduces beach erosion that now contributes to destabilization of homes, roads, and infrastructure.
• Re-establishes a healthy connection between the lower Carmel River and the watershed above San Clemente Dam.
Improves habitat for threatened California red-legged frogs.

"The Carmel River and San Clemente Dam project is the first of its kind, paving the way for similar projects here in California and throughout the country," said Secretary for Natural Resources John Laird. "Thanks to public-private cooperation, this project will help restore 25 miles of sensitive steelhead spawning habitat and create open space for all Californians to enjoy".