Stockton declares water emergency over golden mussels

Stockton is treating golden mussels as a water-system emergency after city staff said the invasive species had clogged intake screens by about 30% to 40% and could interfere with summer demand at the city’s Delta intake station.

The City Council agenda for June 23 shows a resolution to ratify Stockton’s June 19 local emergency proclamation, suspend the normal monetary cap on the city manager’s contracting and purchasing authority, and allow emergency use of General Fund Contingency and ARPA Contingency money for response costs. Stocktonia reported the council unanimously backed the emergency declaration.

That matters because the issue is not just environmental. It is tied to whether Stockton can keep moving water through the intake system that serves the city. Travis Small, deputy director of water resources in Stockton’s Municipal Utilities Department, told the council the mussels pose an immediate threat to municipal water conveyance at the Delta intake station. The city said it was spending $209,000 to clean underwater screens and other equipment.

Why Stockton is sounding the alarm

The local emergency gives the city a faster way to respond, buy materials, and hire help as needed. San Joaquin County has already declared its own local emergency over golden mussels, and county officials said they are seeking coordination, funding, technical assistance, and infrastructure protection resources.

California’s Department of Water Resources says golden mussels can clog pipelines, screens, and filters, and notes that the first North American detection was at the Port of Stockton in October 2024. That makes Stockton both the place where the problem was first found and one of the places now feeling the pressure most directly.

What residents should watch

The key question now is whether the city can keep the intake system clear enough to meet demand as summer use rises. The reports point to risk, not a confirmed shortage. Residents should watch for more spending decisions, more cleanup work, and any signs the emergency response expands beyond today’s screening and maintenance effort.

Sources

• City of Stockton City Council agenda packet — golden mussel emergency ratification item
• San Joaquin County Board of Supervisors — local emergency proclamation for golden mussel
• California Department of Water Resources — invasive mussel mitigation page
• Stocktonia — Stockton water-supply threat from golden mussels
• CBS Sacramento — San Joaquin County golden mussel impacts and federal help