Mendocino County CA data center moratorium (Sept 2026)
Mendocino County, CA — Board of Supervisors Urgency Ordinance: 45-Day Moratorium on New Data Centers (September 2026)
Mendocino County, CA · Mendocino County Board of Supervisors urgency ordinance adopting temporary data center moratorium, September 2026; Mendocino Voice; Press Democrat
- Status
- In effect
- Expires
- August 21, 2028
- Applies to
- Mendocino County planning staff (cannot accept/process/approve new data center applications); data center applicants seeking new development in unincorporated county
- Enforced by
- Mendocino County Community Development Services; Board of Supervisors
The Mendocino County Board of Supervisors voted 5-0 to adopt an urgency ordinance placing a 45-day moratorium on all new data center proposals in unincorporated Mendocino County, effective immediately (~September 2, 2026) and running through approximately October 16, 2026. The county code did not previously define or regulate data centers, meaning a facility could be approved through a routine building permit with no public process. The moratorium buys time for the county to develop a proper permanent ordinance. A renewal hearing is expected at the October 6 board meeting, with supervisors expected to extend the pause for one to two years. Community concerns include air pollution, noise from diesel generators and cooling systems, and the potential to undo local progress on carbon-emission reductions.
Who is protected: Mendocino County residents and ratepayers; rural communities threatened by noise, air quality, and carbon-emission impacts of data center development
Legal detail
Mendocino County Board of Supervisors urgency ordinance (September 2026): 45-day moratorium on acceptance, processing, and approval of applications for new data center development in unincorporated county. Urgency ordinance takes effect immediately without waiting for normal posting period. Prior county code had no data center definition, creating a regulatory gap allowing bypass via routine building permit. Board directed staff to develop a permanent data center ordinance. Deputy County Counsel anticipated return to board October 6, 2026 for a renewal ordinance hearing to extend the moratorium 1-2 years during permanent-ordinance development. Vote: 5-0 (unanimous).
Key facts
| Jurisdiction | Mendocino County, CA |
|---|---|
| Level | County |
| Strength | Moderate |
| Enacted | September 2, 2026 |
| Citation | Mendocino County Board of Supervisors urgency ordinance adopting temporary data center moratorium, September 2026; Mendocino Voice; Press Democrat |
| Private right of action | No, agency enforcement only |
| Penalties | Applications not accepted during moratorium period |
| Topics | data-center siting and energy · government use of AI |
| News report | Mendocino County supes ban data centers — for the moment, at least (Mendocino Voice) |
Related data-center siting and energy rules elsewhere
- Superior WI Data Center Moratorium (1-year) · In effect
- Dane County WI Hyperscale Data Center Moratorium · In effect
- Madison WI Data Center Moratorium (1-year) · In effect
- Manitowoc County WI Data Center Moratorium · In effect
- WA SB 5982 (Data Center / Clean Energy) · In effect
- Dayton OH data center moratorium (180-day, Apr 2026) · In effect
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