The Contra Costa County Board of Supervisors has initiated work on a 2026 ballot measure to renew the County’s Urban Limit Line.
The Urban Limit Line, established by Measure C in 1990, prevents sprawl and preserves open space by establishing a boundary beyond which no urban land uses can be designated. It ensures that urban development occurs within established communities where infrastructure and services already exist or are planned.
Proposed adjustments to the Urban Limit Line are detailed in a report County staff presented to the Board of Supervisors on February 25th, 2025. We welcome your comments on the proposed adjustments. You can view the report and the accompanying maps below or on the Envision Contra Costa website. Please send questions and comments to Will Nelson at [email protected]. Comments received by 5:00 PM on June 2nd will be addressed in a follow-up report to the Board of Supervisors anticipated for June or July.
- Urban Limit Line Renewal Materials Staff report for the 2/25/2025 Board of Supervisors meeting
- Presentation for the 2/25/2025 Board of Supervisors meeting
- Urban Limit Line renewal map series
View the proposed Urban Limit Line adjustments on CCMAP by turning on the layer titled “2-25-25 Draft County Urban Limit Line”
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Purpose of the Urban Limit Line (ULL)
- Protects open space and agricultural land
- Prevents sprawl and inefficient use of land that creates traffic, GHG emissions, and pollution
- Focuses development where infrastructure and services already exist or are planned
- Integral to maintaining the 65/35 Land Preservation Standard, which limits urban land use designations to no more than 35% of the county
Proposed Schedule and Next Steps
- March-May 2025: Staff seeks feedback from the public, cities, MACs, and CPC
- June/July 2025: Staff presents above feedback and draft ballot measure to Board of Supervisors and receives direction
- February 2026 (sooner, if possible): Board of Supervisors hearing to consider placing ULL renewal measure on ballot for June 2, 2026, Primary Election
There is no action for Tuesday, other than to receive and file a report. Staff is asking the Board of Supervisors to direct staff to take the steps necessary to place a ULL renewal measure on the June 2026 Primary Election ballot.
- Maps (50-pages) – click here
- Presentation — click here
BACKGROUND:
Brief History of the Urban Limit Line
On November 6, 1990, Contra Costa County voters approved Measure C, the 65/35 Contra Costa County Land Preservation Plan (the “65/35 Plan”), which established various mechanisms aimed at containing urban sprawl and protecting resources like agricultural land and scenic ridges. The most significant and impactful of these mechanisms are the 65/35 Land Preservation Standard (the “65/35 Standard”) and ULL. Pursuant to the 65/35 Standard, no more than 35 percent of the land in the county may be designated for urban uses (residential, commercial, industrial, etc.) in the General Plans of the County and 19 cities, and at least 65 percent must be designated for agriculture, open space, parks, and other non-urban uses. Meanwhile, the ULL establishes a boundary beyond which no urban land uses may be designated. Working together, the 65/35 Standard and ULL limit the geographic extent of urban development in the county.
Measure C was set to expire on December 31, 2010. On November 7, 2006, county voters approved Measure L, which carried forward most of the elements of Measure C while adding provisions for periodic ULL review and establishing different processes for expanding the ULL by 30 acres or fewer and more than 30 acres. Measure L is in effect through December 31, 2026.
