Critical Areas Ordinance (CAO)
Stay up to date with the Critical Areas Ordinance
The Critical Areas Ordinance (CAO) is a set of development regulations that all cities and counties in Washington State must adopt and enforce under the state’s Growth Management Act (GMA). The GMA requires that all critical areas be designated and that all functions and values of critical areas be protected (RCW 36.70A.172). The CAO is designed to protect specific environmentally sensitive areas and safeguard the public from natural hazards such as floods and landslides. The purpose of the proposed code amendment is to align the City’s CAO with current state law and incorporate best available science (BAS) ahead of the year-end deadline.
Every ten years, counties and cities are required to take legislative action to review and, if needed, revise their comprehensive land use plans and development regulations to ensure the plans and regulations comply with the requirements of the GMA.
What is a Critical Area?
Critical areas include wetlands, streams, lakes, steep slopes, fish and wildlife habitats, flood zones, and Wellhead Protection Areas. These are defined in RMC 4-11-030.

Why does Renton have Critical Areas Regulations?
Protect Nature and Wildlife
Manage development to protect environmental quality, support a variety of species and habitats, and restore damaged natural areas whenever possible.Keep People and Property Safe
Prevent issues like flooding, landslides, and hazards from old coal mines.Ensure Activities Don’t Harm Critical Areas or Public Safety
Make sure any activity in or near Renton's critical areas does not threaten public safety, cause nuisances, or harm the essential functions of these areas—such as preventing floods, cleaning water, and providing habitat.Follow State and Local Laws
Make sure Renton meets requirements like the Growth Management Act, the State Environmental Policy Act, and the City Comprehensive Plan.Guide Smart Development
Give city staff the information they need to review and make decisions about projects near critical areas so we can balance growth with environmental protection.Protect Our Rivers and Streams
Take care of places like the Cedar River and other local waterways, ensuring they remain healthy for fish, wildlife, and our community.

Why are updates to Critical Areas Regulations important?
Washington’s Growth Management Act (GMA) requires cities and counties to periodically review and update their critical areas ordinances to reflect best available science and current state guidelines. These updates must account for new research on environmental risks, species protection, and mitigation strategies. Cities in Washington periodically update their critical areas codes mainly to comply with mandatory state law reviews, reflect advancements in science, and address local environmental and safety concerns.
The proposed revisions to the CAO are based on the latest scientific data. While the code details are still being finalized, the substantial anticipated updates include:
Streamlined code language: Clarifying regulatory terms, updating definitions, and ensuring references are consistent with current state law and scientific standards.
Addition of Channel Migration Zone (CMZ) regulations from the SMP: The provisions to address how river and stream channels may shift over time, better protecting public safety and natural habitats.
Wetlands alignment: Modifying requirements and standards to ensure Renton's regulations match the most recent state guidance on wetlands protection.
Timeline
Updates to the Critical Areas Ordinance must be completed by the deadline of December 31, 2025.
Public Outreach:
The Community and Economic Development Department is hosting public outreach August - October 2025
TBD: Planning Commission Deliberations and Recommendations
TBD: Planning & Development Committee Deliberations and Recommendations
September 17, 2025: Public Hearing
The Public Hearing for Planning Commission has been scheduled for Wednesday September 17th at 6:00PM. See the Planning Commission webpage for additional details as they become available.
Docket Group 19B, D-235: 2025 Critical Areas Ordinance (CAO) Update, LUA25-000284, ECF
Public comment period for CAO Update is open until close of business on October 1, 2025 (Wed) at 5:00pm. Please send comments by emailing planningcommission@rentonwa.gov or submitting them online at https://rb.gy/vaqabf.
Please find Public Hearing 09/17 slides here.
September 8, 2025: Planning & Development Committee Briefing #2
September 3, 2025: Planning Commission Briefing #2
Agenda Packet
February 5, 2025: Planning Commission Briefing #1
Agenda Packet
January 27, 2025: Planning & Development Committee Briefing #1
Agenda Packet
Thank you for your contribution!
Help us reach out to more people in the community
Share this with family and friends