Yolo County Streamlines Parcel Mapping with a Modern GIS Foundation

Yolo County, California, delivers a wide range of public services—from property assessment and election administration to agricultural oversight and infrastructure management. Parcel data underpins many of these services, supporting everything from assessment records to jurisdictional boundaries and geographic information system (GIS) applications.

To support operational excellence and long-term innovation, the county partnered with Esri partner Sidwell to implement ArcGIS Parcel Fabric within ArcGIS Enterprise, modernizing parcel management and establishing a unified system for managing parcel data.

Historically, parcel mapping in the Assessor’s Office relied on a CAD-based workflow that operated independently from the county’s GIS environment. While Yolo County had already invested in GIS, parcel data remained isolated within CAD assessor maps. Maintaining alignment between systems became increasingly difficult, particularly as staff turnover and competing priorities limited consistent system maintenance.

“Our assessor maps were drawn in CAD and then essentially redrawn again in GIS,” said assessor Jesse Salinas. “We knew there had to be a way to streamline that process.”

This duplication created inefficiencies and increased the risk of inconsistencies, underscoring the need for a more sustainable approach. In response, the county set out to establish a complete parcel fabric, eliminate redundant workflows, improve parcel accuracy, and create a centralized dataset that could support multiple departments.

To achieve these goals, Yolo County partnered with Esri business partner Sidwell, a firm specializing in land records and GIS solutions. Together, they designed a phased migration strategy to transition from the legacy CAD system to a modern GIS environment built on ArcGIS Parcel Fabric within ArcGIS Enterprise.

The project began by converting legacy CAD data into a structured geodatabase using the Local Government Information Model. This step ensured that parcel geometry and associated attributes would be preserved and standardized within the GIS environment.

More than 1,600 assessor map files were systematically converted and integrated into the new system. During this process, county staff continued to update parcels in parallel, ensuring that daily operations remained uninterrupted while the migration progressed.

Once the parcel fabric environment was fully established, Yolo County completed the transition away from CAD-based mapping. Parcel data is now maintained entirely within ArcGIS Enterprise, providing an authoritative source of truth across the organization and eliminating the need for duplicate workflows.

A key element of the implementation was ensuring that county staff could confidently adopt and sustain the new system. To accomplish this, county staff leveraged in-person training sessions provided by Sidwell that were designed around Yolo County’s real-world workflows and data challenges.

Rather than focusing solely on theory, the training emphasized practical application. Staff learned how to manage parcel fabric, maintain assessor maps, and incorporate new validation tools into their daily routines.

This hands-on approach enabled a smooth transition, equipping the team not only to operate within the new environment but also to build long-term expertise. The investment in knowledge transfer proved critical in establishing a strong foundation for continued success.

The transition to ArcGIS Parcel Fabric produced measurable benefits across Yolo County’s operations by eliminating long-standing duplicate workflows.

As GIS manager Mary Ellen Rosebrough-Gay explained, maintaining parcel data across separate systems created unnecessary complexity and inefficiency: “The geometry and attributes used to be duplicated between CAD and GIS,” said Rosebrough-Gay. “With Parcel Fabric, we were able to eliminate that duplication and streamline the entire process.”

As a result, parcel maintenance has become more efficient, with updates now being performed within a single system. Built-in topology rules and validation tools help staff identify and resolve errors during editing, ensuring spatial accuracy and reducing the need for rework.

This streamlined approach simplifies daily workflows, allowing staff to focus on maintaining high-quality parcel data and processing updates more quickly. The county has reduced its backlog and improved service delivery to internal and external requests.

In creating a centralized parcel dataset, Yolo County has established a strong foundation for expanding GIS across the organization. Today, GIS supports a growing number of initiatives, including election management and voter services, agricultural monitoring programs, county facility asset management, homeless point-in-time surveys, and public safety efforts such as district attorney investigations. Within the Assessor’s Office, GIS-driven tools provide appraisers with deeper insight into comparable sales and rental data, supporting more accurate and efficient property assessments.

With a modern GIS foundation in place, Yolo County has moved from disparate parcel mapping processes to a unified environment for managing parcel data across departments. This foundation supports expanded use of ArcGIS technologies for analysis and decision-making, positioning the county to adapt and continue driving innovation.