Water in storage, October 2026
At the end of October 2026, San Luis Reservoir, which holds the imported water Santa Clara County draws through the Pacheco tunnel held 1.36 million acre-feet, up 27.4% on a year earlier.
An acre-foot is enough water to cover an acre a foot deep, about what two or three households use in a year. Storage is what came in less what went out: rain and snowmelt fill the reservoirs in winter and spring, and releases for farms, cities and rivers draw them down through summer and fall. So the line moves with operating decisions and water transfers as well as with the weather, and a low reading in autumn is the cycle, not a crisis.
The heavier line is the 12-month average, 1.46 million acre-feet, which takes out the yearly cycle; compare a month with the same month in other years rather than with the month before. A month where any of the reservoirs has no reading is left blank rather than summed short.
Source: California Department of Water Resources, California Data Exchange Center, monthly reservoir storage. Auto-generated each build.