Yolo County Subvention Map 10/11

This data depicts the land enrolled in Williamson Act and/or Farmland Security Zone Contracts and does not necessarily provide information as to the location of Agricultural Preserves within each county. Please note this data is submitted to the state by participating counties and as such reflects the counties’ data. Although we are working to have all participating counties provide updated information, only some of the data is up to date as of the current year as some counties have not submitted data for several years or they have submitted paper maps that have not yet been digitized. The most current and up to date site specific data can be obtained from the individual participating counties as the status of enrolled lands may change throughout the year. Therefore, you are encouraged to verify specific data with the individual county or counties before proceeding with any specific projects or relying on this data for in depth analysis.

Subvention Act GIS Map

Every year the Assessor’s Office is required to submit a report about the lands involved in the Williamson Act. A required part of this report is a physical map and GIS layer that depicts the boundaries and some characteristics about the properties involved in the Williamson Act. The deadline for the submission of the report and map is October 31.

Methodology for the GIS portion

The Assessor’s Office will provide a digital list of the APNs and Williamson Act status of the properties currently involved.

GIS will take that list and join it to the current parcel layer ensuring that there is a complete match.

Once matched a layer of the Williamson Act parcels is created and that will be the geographic basis for the GIS portion of this exercise.

The Williamson Act Parcels will be unioned with the USDA Soils layer and the DOC FMMP layer.

Once the union happens several queries of the data will occur.

• The first is to determine which parcel portions are designated Prime and Non-Prime from the Assessor’s designations.

  • These will be assigned the value of Prime Active and Non-Prime Active

• Next from the portions that are designated Both in the Assessor’s designations the following will occur

  • Query the attributes of the Soils and FMMP that were unioned with the parcels (the query criteria for Prime has already been created)

  • Those that qualify as Prime are assigned the value of Prime Active

  • Those that remain with the Both designation will be assigned the value of Non-Prime Active

• Then the portions that are designated Non-Renewal from the Assessor’s designations need to be queried to determine prime and non-prime and assigned the corresponding value

• Finally parcels that have a Base Year designation will be identified with a column signifying yes for Base Year values.