The Permit Sonoma GIS Parcel Base dataset represents unincorporated lands within the County of Sonoma, California AND was prepared per use in Mapping Study and Analysis for Onsite Wastewater Treatment Systems**.

The parcel layer was digitized from official Assessor Parcel (AP) Maps which were originally maintained on mylar sheets and/or maintained as individual Computer Aided Design (CAD) drawing files (e.g., DWG). The CRA office continues to maintain the official AP Maps in CAD drawings and Information Systems Department/Geographic Information Systems (ISD/GIS) staff apply updates from these maps to the seamless parcel base in the County’s Enterprise GIS.

The primary difference between Sonoma County Information Systems Department/Geographic Information Systems (ISD/GIS) maintained parcel base and Permit Sonoma GIS Parcel Base is as follows:

1. Not seamless - placeholders and incorporated (city) lands have been omitted (Note: there are 9 cities within the County of Sonoma)

2. Due to the sensitivity of land development dependent data (General Plan Land Use, Base Zoning, Combining Districts/Zones), parcel adjustments by County of Sonoma - Clerk Recorder Assessor (CRA) and represented in Information Systems Department/Geographic Information Systems (ISD/GIS) seamless parcel base are regularly reviewed. Parcel rectification is justifiable per lot line adjustments, mergers, splits & subdivisions. In the case of severe adjustments and/or errors, an entire area and/or single parcel will be swapped. The dataset's origin is based on fiscal year 2005/06 seamless parcel base.

** Mapping Study and Analysis for Onsite Wastewater Treatment SystemsWith various OWTS-related regulations, especially the Russian River pathogen TMDL, the Board of Supervisors of Sonoma County decided to fund an OWTS-focused, county-wide mapping study. In 2021, the Board allocated $250,000 for the development of a high-level mapping study and analysis to identify areas within Sonoma County with low, moderate and high densities of septic infrastructure, where that infrastructure is located in relation to new or foreseeable TMDLs imposed by the State Water Quality Control Board, and where if geographically, politically and economically feasible, existing or new special service district or wastewater management district boundaries could be created or modified to allow for the management and support of community wastewater needs, including but not limited to, sewer conveyance and treatment, individual and shared septic systems, and alternative wastewater treatment technologies.

The Permit Sonoma GIS Parcel Base dataset represents unincorporated lands within the County of Sonoma, California AND was prepared per use in Mapping Study and Analysis for Onsite Wastewater Treatment Systems**.

The parcel layer was digitized from official Assessor Parcel (AP) Maps which were originally maintained on mylar sheets and/or maintained as individual Computer Aided Design (CAD) drawing files (e.g., DWG). The CRA office continues to maintain the official AP Maps in CAD drawings and Information Systems Department/Geographic Information Systems (ISD/GIS) staff apply updates from these maps to the seamless parcel base in the County’s Enterprise GIS.

The primary difference between Sonoma County Information Systems Department/Geographic Information Systems (ISD/GIS) maintained parcel base and Permit Sonoma GIS Parcel Base is as follows:

1. Not seamless - placeholders and incorporated (city) lands have been omitted (Note: there are 9 cities within the County of Sonoma)

2. Due to the sensitivity of land development dependent data (General Plan Land Use, Base Zoning, Combining Districts/Zones), parcel adjustments by County of Sonoma - Clerk Recorder Assessor (CRA) and represented in Information Systems Department/Geographic Information Systems (ISD/GIS) seamless parcel base are regularly reviewed. Parcel rectification is justifiable per lot line adjustments, mergers, splits & subdivisions. In the case of severe adjustments and/or errors, an entire area and/or single parcel will be swapped. The dataset's origin is based on fiscal year 2005/06 seamless parcel base.

** Mapping Study and Analysis for Onsite Wastewater Treatment SystemsWith various OWTS-related regulations, especially the Russian River pathogen TMDL, the Board of Supervisors of Sonoma County decided to fund an OWTS-focused, county-wide mapping study. In 2021, the Board allocated $250,000 for the development of a high-level mapping study and analysis to identify areas within Sonoma County with low, moderate and high densities of septic infrastructure, where that infrastructure is located in relation to new or foreseeable TMDLs imposed by the State Water Quality Control Board, and where if geographically, politically and economically feasible, existing or new special service district or wastewater management district boundaries could be created or modified to allow for the management and support of community wastewater needs, including but not limited to, sewer conveyance and treatment, individual and shared septic systems, and alternative wastewater treatment technologies.