The California State Water Project was approved by the legislature in 1959 and bonds for its construction were narrowly approved by California voters in November 1960 (Proposition 1). The California Department of Water Resources maintains this profile for the State Water Project:
The Department of Water Resources claims the overall “Table A amounts” of the State Water Project contractors total 4.23 million acre-feet of water per year, but the project has never delivered that much water at any time in its history; in fact, during the peak years of 2005 and 2006, it delivered no more than about 3.7 million acre-feet. Deliveries dropped dramatically in subsequent – and drier — years. In 2007 the SWP delivered about 2.98 million acre-feet, and it delivered 1.96 million acre-feet in 2008.
Read more about the State Water Project: Project Operations And Financial Performance (2009)
During the drought of 1991, the SWP was able to deliver only .5 million acre feet of the 4.2 million acre feet of water under state contract. Controversy over the project’s capacity during droughts led to adoption of the secretly negotiated “Monterey Agreement” in 1994 and project contract amendments in 1995.