Mill Creek Dam

Calling back the salmon

About the Project

Mill Creek, nestled in the coastal redwoods north of Santa Cruz, provides salmon with critical cool water flows in the summer months as it joins San Vicente Creek and then meets the ocean. These favorable conditions spurred state and federal agencies to identify the San Vicente Creek watershed as a high priority for coho salmon recovery in the Santa Cruz Mountains.

Two dams located on the San Vicente Redwoods Preserve, co-owned by Sempervirens Fund and Peninsula Open Space Trust, along Mill Creek impede fish passage in the watershed. The lower dam is a defunct 12-foot-tall, 25-foot-wide concrete structure built more than 100 years ago to service past mining and logging activities. Removal of the dam will release gravel and sediment that is trapped behind the dam and is essential for salmon spawning habitat. Upstream sits a slightly larger dam, built in the mid-1900s; additional planning and assessment work is envisioned to determine the feasibility of removing that dam in the future.

The region surrounding the dam holds cultural significance to the descendants of the Mutsun and Awaswas speaking peoples who have occupied the region for generations. The Amah Mutsun Land Trust, a nonprofit Tribal land trust created by the Amah Mutsun Tribal Band, is partnering on the project to conduct cultural resource surveys, remove invasive species, and plant native species. Following removal in the fall of 2021, Tribal members will gather for their ceremony, “Calling Back the Salmon,” for the first time since colonization.

The 2020 CZU Lightning Complex burned the entire 8,500 acre San Vicente Redwoods Preserve, melting a water line owned by Cemex, Inc. on Mill Creek and increasing concerns with the structural integrity of the dam to be removed.

FACTS AT A GLANCE
Owner: Sempervirens Fund and Peninsula Open Space Trust
Size: 12 feet high and 25 feet wide
Project Cost: $775,500
ORF Investment: Feasibility study, dam removal (permitting, design, project management, dam deconstruction), communications, cultural resources survey, research and outreach, Calling Back the Salmon Tribal ceremony
Miles Opened: .25 miles
Fish: Central California Coast coho salmon and steelhead
Status: Removal scheduled 2021


RESOURCES
OUTCOMES
  • Restore .25 miles of ideal cold water habitat for Central California Coast coho salmon and steelhead
  • Renew the cultural ceremony, “Calling Back the Salmon,” by the Mutsun and Awaswas speaking peoples
  • Improve spawning habitat by releasing coarse substrate trapped behind the lower dam
  • Reduce risk of uncontrolled breach of the lower diversion dam, located upstream from Davenport
  • Revegetate the project area with native plant species

Project Partners

Sempervirens Fund

Peninsula Open Space Trust

Save the Redwoods League

Amah Mutsun Land Trust

California Department of Fish and Wildlife

State Coastal Conservancy

Resources Conservation District of Santa Cruz County

Cemex, Inc.

Waterways Consulting, Inc.