Congressman David Valadao joined Reps. Vince Fong, Jim Costa, and Josh Harder on June 2 to urge U.S. Fish and Wildlife Service Director Brian Nesvik to provide immediate emergency federal funding to address the spread of invasive golden mussels in California waterways.
The lawmakers sent a letter warning that without prompt federal support, escalating costs will fall on California water agencies, farmers, and communities as the species continues to spread. The letter states, “Golden mussels pose a unique threat given they reproduce at exponential rates, clog water delivery systems, and damage water infrastructure.” It continues: “Golden mussels spawn several times throughout the year, producing microscopic larvae in numbers reaching up to one million eggs annually per female. This has led to the unrestrained spread of larvae throughout California and has made eradication efforts nearly impossible.”
The letter further explains that colonies infiltrate critical infrastructure such as pipelines and pumps by attaching to surfaces: “These impacts have reduced water conveyance capacity, damaged equipment, and driven up maintenance costs for water agencies and ratepayers alike.” After being detected in the Sacramento-San Joaquin Delta in late 2025, golden mussels have rapidly expanded their range into major systems like the State Water Project and Central Valley Project. These projects supply millions of Californians with water and irrigate more than 4,000 acres of farmland.
Kern and San Joaquin Counties recently declared local states of emergency due to active infestations within critical infrastructure. The declaration cited “immediate operational risks” affecting drinking water supplies, agriculture, energy production, and regional economic stability.
The lawmakers’ letter urges USFWS to expedite emergency funding through existing authorities; prioritize California for grant assistance; increase allocations for early detection efforts; coordinate with other federal agencies including the Bureau of Reclamation; expedite listing golden mussels under the Lacey Act; and develop a national control plan for prevention and eradication.
