6/19: All SBPL locations will be closed on Wednesday, June 19 for Juneteenth.


5/21-7/14: Eastside Library will be closed due to construction work.


Water Treatment


William B. Cater Water Treatment Plant


From its perch midway up the Santa Ynez Mountains, The William B. Cater Water Treatment Plant treats visitors to a spectacular view of Santa Barbara and the ocean beyond. This City facility provides an important contribution to a vibrant community whose scenic blend of historic architecture, thriving arts, pristine coastline, and small-town charm makes it a renowned destination.

The William B. Cater Water Treatment Plant treats raw water received from Lakes Gibraltar and Cachuma to drinking water standards, producing more treated water than any other source within the South Coast water system. It provides the city of Santa Barbara with the majority of its drinking water while also supplying treated water to the districts of Montecito Water, Carpinteria Valley Water, Goleta Water, and La Cumbre Water.

The plant employs a conventional treatment process of coagulation, flocculation, sedimentation, and filtration to treat up to 37 million gallons of water per day (mgd). Constructed in 1964 with an original capacity of 10 mgd, it is the oldest treatment plant within the South Coast water system. In 1981, addition of five new filters increased water production to the plant's present capacity.

Over the past 40 years, drinking water regulations have become more stringent while various components within the plant have worn out or become obsolete. Though challenged by these circumstances, plant staff consistently produced a safe and reliable drinking water supply for the citizens they serve. Improvements completed in 2004 are one step in a series of upgrades that allow the William B. Cater Water Treatment Plant to continue to provide a reliable source of treated water that meets increasingly more stringent regulatory requirements for the foreseeable future.

In May 2017, the Charles E. Meyer Desalination Plant began treating water. Learn more about the Desalination Plant here.

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