Effort Ramps Up to Keep Golden Mussels Out of Millerton Lake

Agriculture

By SJV Water

Published 1 hour ago on

May 13, 2026

Fast-spreading invasive golden mussels coat this boat motor propeller. (California Department of Fish and Wildlife)

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Friant Water Authority is planning an “aggressive” outreach campaign before Memorial Day weekend in an effort to keep golden mussels out of several eastside reservoirs, including Millerton Lake.

Portrait of SJV Water Reporter Lisa McEwen

By Lisa McEwen

SJV Water

The campaign includes social media and handouts urging boaters “Clean, Drain and Dry” all watercraft and trailers. This is especially important for boaters who have visited the Sacramento-San Joaquin Delta, ground zero for the golden mussel infestation.

Friant is working with California State Parks and the Bureau of Reclamation to remind boaters to check and clean watercraft before launching into Millerton Lake, or any water body, said Katie Duncan, water resources engineer at Friant Water Authority’s April 30 board meeting.

Friant is also working on similar messaging with the U.S. Army Corps of Engineers, which manages dam infrastructure at Pine Flat, Kaweah Lake, Lake Success, Lake Isabella though Duncan said nothing is confirmed yet.

Kaweah Lake park ranger Hayden Doyel said signs with photos of golden mussels are posted at docks and on bulletin boards around the lake to warn boaters of the risk of transporting any invasive mussel, including quagga and zebra.

“We are monitoring for all mussels but we haven’t found anything yet,” he said.

A flyer from the state of California on how to prevent the spread of golden mussels by cleaning, draining, and drying your boat

The golden mussel, a prolific bi-valve mollusk, hitchhiked across the ocean into the Delta at least two years ago. It is native to Southeast Asia. Since then, it has spread throughout the state, clogging infrastructure in the state’s vast water delivery network, including the southern portion of the Friant Kern Canal near Arvin where Arvin-Edison Water Storage District has already spent $2.8 million fighting the mussels.

The Kern County board of supervisors will consider declaring a state of emergency May 12. To the north, San Joaquin County already has declared a local emergency.

The outreach campaign is part of a larger control plan enacted by Friant in April, when the board approved spending $408,000 for monitoring and research with consulting firm Dudek.

Duncan said Friant is optimistic that Millerton’s lower temperatures and calcium concentrations may limit the mussel’s ability to take up residence. That doesn’t mean the golden mussel veligers, or larvae, can’t be transported to local tributaries or canals where warmer temperatures are more conducive to infestation.

Other Mussel News

• Eighteen Friant member districts filled out surveys in April as part of a system vulnerability analysis. Dudek will provide specific recommendations to districts based on their water supply and infrastructure.

• The board of Lindmore Irrigation District in Tulare County approved a $30,000 contract in February with Dudek to develop a monitoring and mitigation plan tailored to the district’s operational needs.

• Golden mussels were spotted April 11 in the Pleasant Valley pipeline in Fresno County, forcing farmers to go without surface water for five days while the pipeline was cleaned.

Sarah Woolf, consultant with Water Wise, is also working as Pleasant Valley Water District’s general manager. She said landowners were surprised how quickly mussels arrived.

“I think it was definitely a surprise how detrimental it is to facilities. It was quite shocking,” she said.

Lindmore’s Assistant General Manager Chris Hunter added that local agencies still need a rapid, coordinated statewide response.

“This issue extends well beyond agriculture,” he said.

Legislative Response

Three golden mussels bills have been introduced. However, Friant lobbyist Mike Villines said, “None of them do what they should, and that is bring money to fight golden mussels.”

Senate Bill 1772 proposes creating a statewide database to voluntarily track the movement of vessels, equipment, and other vectors among California waterbodies, providing waterbody managers with information on the prior contamination status of these vessels.
Assembly Bill 2032 would require the California Department of Fish and Wildlife’s Invasive Species Program to develop, by April 1, 2027 voluntary guidance for public and private agencies that operate water supply systems to develop control plans.
Assembly Bill 1894 would prevent a public agency from prohibiting imported water deliveries for groundwater replenishment due to invasive mussels unless there is substantial, documented evidence of a proven health and safety risk as a result of the invasive mussels.

About the Reporter

SJV Water Reporter Lisa McEwen grew up in Tulare County. She has reported on agriculture and other issues for a wide variety of publications, including, Ag Alert, Visalia Times-Delta, the Fresno Bee and the Tulare and Kings counties farm bureau publications.

About SJV Water

SJV Water is an independent, nonprofit news site covering water in the San Joaquin Valley, www.sjvwater.org. Email us at sjvwater@sjvwater.org