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 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

Open Space Subvention payments totaled more than $863 million between 1972 and 2010.  Despite elimination of OSSA payments since the FY 09/10 budget, Williamson Act enrollment information provided by counties and cities is critical in order to document the level of participation in the program and the impact the loss of OSSA payments is having on local governments. Enrollment information was the basis for the biennial Land Conservation Act Status ​Report, which provided information to the Legislature and general public on the status of the Program among counties and cities.

The recent passage of Senate Bill 574 eliminated the biennial Williamson Act Status Report, and has simplified Williamson Act reporting requirements. Enrollment information will now be collected in Geographic Information System form, and will be made public on the Department's website biennially. ​More information and statistics are available on the Reports and Statistics page.

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