The valley is rapidly evolving from a predominantly agricultural area to an industrial and urban center. Accordingly, more of the county's water consumption shifts from agricultural to domestic and industrial use.
The South Santa Clara Valley Water Conservation District builds the Chesbro and Uvas dams to increase storage and recharge efforts. The Central Santa Clara Valley Water Conservation District is annexed to the Santa Clara Valley Water Conservation District. Water conservation education efforts begin in earnest.
In 1952 the county board of supervisors forms the Santa Clara County Flood Control and Water Conservation District. Its goals are to protect the county from flooding and supplement local water supply with water imported from outside the valley. The "Christmas Week" floods of 1955 leave thousands homeless. The Guadalupe River alone floods 8,300 acres, the worst flood on that river in recorded history.
The county's population swells to 642,000 by 1960.
President John F. Kennedy and Gov. Edmund G. "Pat" Brown join in a dedication ceremony in 1962 for the San Luis Dam and Reservoir west of Los Baños. The dam takes five years to build, and by 1987 is the source for imported federal Central Valley Project water to Santa Clara Valley through the Pacheco tunnel.
In 1965 the state of California begins delivering water to Santa Clara County via the 72-inch South Bay Aqueduct, which brings water about 40 miles from the Sacramento-San Joaquin River Delta to the county.
The valley's first treatment facility, the Rinconada Water Treatment Plant, begins operation in Los Gatos.
In 1968 the Santa Clara Valley Water Conservation District and the Santa Clara County Flood Control and Water Conservation District merge, forming one agency to manage the water supply and flood programs for most of the county.
By 1969 the addition of imported water to the local recharge efforts halts more than 40 years of land subsidence.