Critical Areas Ordinance (CAO)
Join us for Ask an Expert
Learn more about the topics in the Critical Areas Ordinance:
- What’s behind local flooding—and how the update could help.
- Why wetlands are worth protecting (for people AND wildlife).
- How fish, plants, and habitat fit into the bigger picture.
All events at the Atrium (3000 Pacific Ave SE) before the Planning Commission.
Come for the questions, stay to engage in local policy decisions!
Ask a Flood Expert
- Wednesday, March 18, 5:30-6:15
- In person and online: https://us02web.zoom.us/j/84580250495
Ask a Wetland Biologist
- Wednesday, April 1, 5:30-6:15
- In person and online: https://us02web.zoom.us/j/82708325586
Ask a Fish and Plant Biologist
- Wednesday, April 15, 5:30-6:15
- In person and online: https://us02web.zoom.us/j/85315783977
Thurston County is updating the Critical Areas Ordinance!
Thurston County has started updating the Critical Areas Ordinance (CAO), with completion planned for the end of 2026. The CAO guides how land can be developed safely near environmentally sensitive areas. It draws on the best available science to balance property use with the protection of human health and safety, water quality, and wildlife habitat – for today and future generations.
The CAO update is currently being reviewed by the Planning Commission while County staff works on collecting Best Available Science (BAS) and writing draft code. Nothing is finalized yet, and the County wants to hear your feedback and ideas. Through this year, there will be many opportunities for the community to share feedback and ask questions. You input will be essential in shaping this process.
Updates to the CAO could include:
- Using the best available science to protect critical areas.
- Making it easier for landowners to engage in conservation work on their properties.
- Clarifying the permitting process.
If you have questions about the current code, project specific concerns, or need help with permitting, please contact the Thurston County BDC. For questions about Thurston County's Critical Areas Ordinance Update, please contact Associate Planner Claire Swearingen at Claire.Swearingen@co.thurston.wa.us or call 360-968-9989.
Learn more from our CAO Update Fact Sheet.
Sign Up for Email Updates!
Submit Comments & Best Available Science!
The Five Critical Areas
Washington state law, Growth Management Act (GMA), requires cities and counties to protect five types of critical areas, including:
- Geologically hazardous areas at risk for landslides, like cliffs or steep slopes. Fact Sheet.
- Frequently flooded areas such as floodplains and high groundwater zones. Fact Sheet.
- Critical aquifer recharge areas that help water soak back into the ground, so there's plenty for us to drink and fish to swim in. Fact Sheet.
- Wetlands that help filter dirt and pollutants from the water as it soaks back into the ground. Fact Sheet.
- Fish and wildlife habitat conservation areas like lakes, rivers, streams, prairies, and forests. Streams and Riparian Areas Fact Sheet. Terrestrial Areas Fact Sheet.
Resources: Best Available Science (BAS) and Laws
The Thurston County CAO is detailed in Title 24 of the County Code of Ordinances.
Learn more from the Department of Commerce Critical Areas Handbook.
Learn about Best Available Science from our BAS Fact Sheet.
- 2021 Critical Aquifer Recharge Areas: Guidance Document, Ecology, 2021
- Geologic Planning (Webpage), WA DNR, 2025
Planning Commission Meetings
Throughout the update development process, staff will bring presentations on State guidance, best available science, and policy decisions to the Planning Commission. The Planning Commission will also review code drafts. Community members are encouraged to provide public comment and feedback at any Planning Commission meeting.
|
Meeting Date |
Topic |
Documents and Presentations |
| 9/17/2025 | Introduction to the Critical Areas Ordinance update | |
|
10/1/25 |
Permitting/front counter demonstration |
None |
|
10/15/25 |
Draft schedule overview and prioritization discussion |
|
|
11/5/25 |
Schedule finalization (as needed) |
Meeting Cancelled |
|
11/19/25 |
Overview of state guidance and Best Available Science |
|
|
12/3/25 |
Geologic Hazard Areas Concepts |
|
|
12/17/25 |
Meeting Cancelled - Power Outage |
|
|
1/7/26 |
Invite Department of Natural Resources to present new landslide mapping |
Guest Presentation |
|
1/21/26 |
Critical Aquifer Recharge Areas Concepts |
|
|
2/4/26 |
Frequently Flooded Areas Concepts |
|
|
2/18/26 |
No Critical Areas Ordinance Presentation Planned |
N/A |
|
3/4/26 |
Geologic Hazards code presentation |
|
|
3/18/26 |
Frequently Flooded Areas and Critical Aquifer Recharge Areas code presentation |
|
|
4/1/26 |
Wetlands |
|
|
4/15/26 |
Wetlands and Hydrologic Fish and Wildlife Habitat Conservation Areas |
|
|
5/6/26 |
Dryland Fish and Wildlife Habitat Conservation Areas |
|
|
5/20/26 |
Presentation on Shoreline Master Program and Habitat Conservation Plan integration |
|
|
6/3/2026 |
Invite Department of Fish and Wildlife to present on Fish and Wildlife Habitat Conservation Areas |
|
|
6/17/2026 |
Permit Processes, FWHCAs and Wetlands code presentation |
|
| July 2026 | Final review, public hearing, and recommendation |
History
The first critical areas ordinance was adopted by Thurston's Board of County Commissioners in 1994, in response to the Washington Legislature enacting the Growth Management Act (GMA) in 1990. The last major update was adopted in 2012, with some minor updates since then. Since the last major update, State requirement and the best available science have changed.