Protect Cache Creek from Gravel Mining
One of the world’s largest climate polluters – CEMEX – has applied to Yolo County for a permit to extend its mining operations along Cache Creek for another 20 years until 2047.
CEMEX, an $18 billion company, wants to mine an additional 32 million tons of sand, gravel and rock from lower Cache Creek to use in major construction projects such as dams, highways and urban sprawl.
CEMEX plans to restore this site to a combination of farmland, habitat and “lake features” to be part of a planned 14-mile parkway of other mining sites by 2052. But promises to protect nature from mercury poisoning in the open impoundment pits have already been broken and farmland restoration is falling short.
Over 90% of the Sacramento Valley’s carbon rich, life-enhancing wetlands have been destroyed by unsustainable development. A livable future hangs in the balance.
Cache Creek has some of the greatest potential to support the recovery of nature in Yolo County.
Learn more about what’s at stake and what we can do to reverse the adverse effects of decades of off-channel mining and restore the life cycle to our local watershed.
Loss of Nature
Cache Creek has the potential to again become the environmental backbone of Yolo County. Originating from Clear Lake, the creek flows from the inner coastal mountains through Capay Valley after which its waters once fanned out across the valley floor and joined with the mighty Sacramento River.
Less than 200 years ago, the watershed sustained vast wildlife populations and natural abundance. It was known by the late Wintun elder Bertha Nye Norton as kaltipookapai schlombeck, or “gathering wealth creek.” Rich plant and animal life supported Native Californian lifeways for thousands of years.
Salmon, sturgeon, lamprey, elk, deer, pronghorn, California grizzly bear, beaver, river otter, ring-tailed cats, mountain lions, bobcats, turtles, raptors, and myriad invertebrates all made their home in the riparian forest that spanned for a mile along either side of Cache Creek.
After nearly 200 years of human exploitation, the creek is gradually making an environmental comeback.
Hundreds of people are working day in and day out to administer CPR—Conservation, Preservation, Restoration—to restore nature to Cache Creek.
Climate Impacts
The CEMEX mine uses massive diesel fueled earth-moving equipment to dig up the sand and gravel on site and then generates over 50,000 truck trips a year to deliver the material to its sometimes distant customers. These trips produce more than 3,000,000 vehicle miles traveled (VMT) to the county’s carbon footprint.
A majority of these materials are used in large construction projects outside the county.
Yolo County declared a climate emergency in 2022 calling for a just transition to a carbon neutral county by 2030. Hundreds of Yolo County residents, community-based organizations, the Resource Conservation District, local farmers, Yocha Dehe Tribe, UC Davis and many others collaborated on a new Climate Action and Adaptation plan that was released in Nov. 2024. This award-winning plan outlines 180 detailed actions to curtail climate change and build resilient communities.
Instead of aligning their project with Yolo County’s climate goals, the CEMEX environmental report provides ZERO mitigation measures. Instead, CEMEX promises to create a “GHG Emissions Reduction Plan” AFTER their permit has been secured.
Methyl Mercury Toxicity
CEMEX and other companies along Cache Creek are mining way below the groundwater table. As the 70+ foot deep pits fill with groundwater, methyl mercury, an extremely potent neurotoxin, is being generated by bacteria that thrive in anaerobic conditions.
Mercury is bioaccumulating to toxic levels in fish and can potentially cause serious health problems if the fish are ingested by wildlife or humans.
Over five years ago, the county’s mercury consultant – Darryl Slotton – recommended that “lake management plans” be developed to address the problem. These plans haven’t yet been created, let alone implemented.
The Sierra Club has called out the county’s noncompliance with its own mercury regulations and is demanding these violations be addressed before any new permits are granted. See:
Loss of Prime Farmland
The CEMEX project proposes to fill in two of the wet pits along Cache Creek and return them to agriculture.
Previous mining projects have shown that the so-called “reclaimed” farmland has never been brought back to pre-mining productive standards in terms of crop yields expected from prime farmland. At best the “reclaimed” farmland has resulted in smaller yields of lower-quality crops.
Some organic farmers have had to stop farming organically and resort to conventional, chemical-intensive measures to boost yields.
Local Cache Creek residents are calling for the mined-out area along the creek to be incorporated into an expanded floodplain rather than returned to agriculture with dubious results.
This alternative was not evaluated in the recent EIR despite the significant environmental benefits it would bring.
Groundwater Sustainability
The Yolo Subbasin Groundwater Sustainability plan calls for the protection of groundwater-dependent ecosystems along Cache Creek.
Protections are needed to ensure the availability of groundwater for local domestic and farming needs.
Many farmers experienced their wells dry up during the last drought. The wetland at the Cache Creek Nature Preserve also went dry.
As Yolo County Supervisor Gary Sandy stated during the recent approval of the Teichert-Shiffler mine, it is “reckless” to approve a thirsty mining project that will permanently impact the aquifer.