The Open Space Subvention Act
The Open Space Subvention Act (OSSA) was enacted on January 1, 1972, to provide for the partial replacement of local property tax revenue foregone as a result of participation in the Land Conservation (Williamson) Act and other enforceable open space restriction programs (Government Code §16140 et seq.). Participating local governments have received annual payment on the basis of the number of eligible acres, quality (soil type and agricultural productivity), and, for Farmland Security Zone contracts, location (proximity to a city) of land enrolled under eligible enforceable open space restrictions.
Open Space Subvention payments totaled more than $863 million between 1972 and 2010. Statistics are available in Appendix B of the 2014 Williamson Act Status Report.
The Department of Conservation continues to work with assessors offices and planning departments to document participation in the Land Conservation Act. The FY 2015 Survey of Participation is now available on the Open Space Subvention Payments page.