The California Land Conservation Act was enacted in 1965 and named for its author, Assemblyman John Williamson of Bakersfield. Its purpose was to assure sufficient food supplies, discourage the unnecessary conversion of agricultural lands, discourage urban sprawl, and preserve open space; its impact on rural California can hardly be overstated. According to this 2005 article celebrating its 40th anniversary, "one in three farmers and ranchers enrolled in the Williamson Act would have left agriculture without it."
The Williamson Act is a voluntary program that charges local governments with implementation. Landowners enter into agreements with participating cities and counties to restrict use of their land in return for lower tax assessments. There are currently 16.6 million acres under Williamson Act contract, or nearly one-third of all of the privately held land in the state. The state has until recently compensated local governments for reduced tax revenue, thereby subsidizing Williamson Act contracts. However, Governor Schwarzenegger essentially eliminated funding for the Williamson Act program in July 2009. Whether the program will receive funding moving forward and at what level is still being contested in the state legislature.
Between 2002 and 2007, we lost 16.2 million acres of agricultural land to development nationwide, and this trend shows no signs of abatement. On balance, people are simply willing to pay more for land on which they intend to build McMansions than for land on which to grow food. The amount of funding allocated to the Williamson Act program has a direct correlation to the amount of farmland protected in California. No farms, no food (as the bumper stickers say). And once that land is gone, it's truly gone for good. Unfortunately, this is yet one more case in which the easiest, most expedient thing to cut from the budget may be long-term sustainability.