Scope
Mendocino County Ordinance No. 4561, an urgency ordinance under Government Code Section 65858, provides that the County shall not approve any subdivision, use permit, variance, building permit, site development permit, grading permit or other entitlement, permit or approval for the establishment, expansion or intensification of any Data Center Use or similar high-intensity computing uses, and that no County official or body shall accept as complete, process, approve or issue such permits. Section 4 defines Data Center Use as a facility used primarily or substantially for housing or operating computer servers and related equipment for data processing, storage, cloud computing, artificial intelligence, blockchain or cryptocurrency mining or similar high-intensity computing, and excludes customary accessory server, IT or equipment rooms serving only on-site operations, ordinary office, retail, school, hospital or industrial computer equipment supporting on-site operations, public safety and emergency facilities, and essential telecommunications carrier and public utility facilities not principally used as a commercial data center. It applies to all property in the unincorporated county, with exemptions for fully approved projects, public safety and emergency facilities, essential telecommunications and utility facilities, and minor repairs that add no capacity.
- Geographic scope
- Unincorporated Mendocino County, California
- Jurisdiction
- Local
- Authority type
- Local government
- Issuing authority
- Mendocino County Board of Supervisors
Dates
- Adopted
- 1 September 2026
- Effective
- 1 September 2026
- Scheduled expiration
- See completion condition
- Ended
- Not recorded as ended
- Completion condition
- Section 9 set the ordinance to remain in effect for forty-five days from adoption to 16 October 2026 unless extended by the Board under Government Code Section 65858. On 6 October 2026 the Board adopted Ordinance No. 4562, which extends this moratorium by twenty-two months and fifteen days to 21 August 2028; because of that extension the 16 October 2026 date is not stored as an end date.
- Source document
- 1 September 2026
- Last checked
- 1 November 2026
Summary
On 1 September 2026 the Mendocino County Board of Supervisors adopted Ordinance No. 4561, an urgency ordinance imposing a temporary moratorium on approving and processing permits and entitlements for new, converted or expanded data center uses in the unincorporated county, with listed exclusions such as accessory server rooms serving on-site operations. The ordinance took effect on adoption and was set to run to 16 October 2026 unless extended. On 6 October 2026 the Board adopted Ordinance No. 4562, which extends this moratorium to 21 August 2028. The ordinance does not order existing facilities to close.
What this does not establish
- The roll call printed with the ordinance lists all five supervisors as ayes.
- Section 9 printed an end of 16 October 2026 unless extended; Ordinance No. 4562 extends the moratorium, so no end date is stored for this record and the extension is described in its own record.
- The ordinance applies only in unincorporated Mendocino County; cities in the county are outside it.
Unresolved questions
- Whether the Board ends the extended moratorium before 21 August 2028 after adopting regulations.
Relationships
Supersession means a later instrument replaces the earlier legal effect. Repeal links identify the repeal instrument and the measure it ends. A later implementation or related letter is not treated as a replacement unless the record says so.
- Related, not a replacement Mendocino County (unincorporated): extension of data center moratorium to 21 August 2028 (Ordinance No. 4562) (In effect)
Sources
Primary source: Mendocino County Board of Supervisors page on mendocinocounty.gov
- Mendocino County Code page, Pending and Recently Adopted Ordinances — Lists Ordinance 4561 as adopted 1 September 2026 and Ordinance 4562 as adopted 6 October 2026