Golden Mussels and the Mokelumne: What the Invasion Means for Lodi

The golden mussel invasion that Ag Alert reports is plaguing California farms and water districts is not a distant Delta problem for Lodi. It arrived through the county's front door and is moving toward the county's most important local waterway. San Joaquin County recorded the first golden mussel detection in North America, at the Port of Stockton in October 2024, and in April 2026 became the first California county to declare a state of emergency over the mussel. The threat now runs along the lower Mokelumne River — the river that flows through Lodi, forms Lodi Lake, and irrigates roughly 13,000 acres of Woodbridge Irrigation District farmland. This report traces the risk down three connected pathways: the river and Lodi Lake, the irrigation district that waters local vineyards and orchards, and the EBMUD reservoirs upstream that control everything downstream.