Initial Study Assessment Guidelines (ISAGs) –
Comprehensive Update
Project Background and Overview
The California Environmental Quality Act (CEQA) mandates that public agencies, including the County of Ventura, assess and disclose potential environmental impacts of projects and implement measures to mitigate those impacts before project approval. The County of Ventura adheres to CEQA through the Ventura County CEQA Implementation Manual and the Ventura County Initial Study Assessment Guidelines.
The Ventura County CEQA Implementation Manual and Initial Study Assessment Guidelines were last updated in 2011. A comprehensive update is needed to align these documents with current County policies, CEQA requirements, and other state and federal regulations. Updates to the Assessment Guidelines include clarifications and consolidation of environmental thresholds, methods for impact analysis, and the addition of a glossary and resources to support impact analysis.
The information and resources below highlight several key updates, existing resources, upcoming events, and contact information.
Key Updates
Upcoming Outreach Opportunities
The County is seeking feedback on the updated Assessment Guidelines. Comments can be submitted online, or by email, phone, or mail. Visit the project website at [URL] for more details.
The County will be hosting an Open House on May 8th where County staff will be available to discuss and answer questions about the updated thresholds and impact analysis methods for all environmental topics addressed in the Ventura County Initial Study Assessment Guidelines.
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New/Proposed Documents
Initial Study Assessment Guidelines (2025)
Ventura County Administrative Supplement to CEQA (2025)
ISAGs Summary Sheets
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Existing Resources
Public Resources
Initial Study Assessment Guidelines (2011)
Contact Us
Planning Division
plan.counter@ventura.org
(805) 654-2488
