A virtual public meeting to discuss the Greenwater River CMZ was held Tuesday, Nov. 16, 2021, from 6-8 p.m. on Zoom. The following meeting materials are available:

King County, as service provider to the King County Flood Control District, recently completed a draft channel migration zone study and map on the Greenwater River. 

The Greenwater River CMZ study identifies where future channel migration is expected to occur along 1.2 miles of the river. Following the public comment period and public meeting, the study and map will be finalized, and a public rule amendment will be adopted. Once adopted, the CMZ hazard areas become regulated under the King County Code to reduce flood risks to the public. 

How to use this virtual open house 

Visit each tab to learn more about this study and map. You can also click  Continue  at the bottom to go to the next page.  

To view the open house in a language other than English, use the Translate link at the top of the page. For additional translation assistance, including receiving a response to a question in a language other than English, please call 206-477-4812. 


For more information about the draft Greenwater River CMZ study, map, or public meeting, contact Judi Radloff, Project Manager and Geologist, King County Department of Natural Resources, at 206-263-6844 or [email protected]

If you have questions about the King County Channel Migration Public Rule or CMZ regulations, contact Jim Chan, Permitting Division Director, King County Department of Local Services, at 206-477-0385 or [email protected].  

The King County Flood Control District (District) is a countywide special purpose district created to provide funding and policy oversight for flood risk reduction capital projects and programs in King County. The Flood Control District’s Board is composed of the members of the King County Council. The Water and Land Resources Division of the King County Department of Natural Resources and Parks implements a majority of the District’s flood risk reduction projects and programs.   

King County Department of Local Services (Local Services) works to promote the well-being of residents and communities in unincorporated King County by seeking to understand their needs and delivering responsive local government services. Local Services maintains county roads and bridges, issues permits, manages land use planning, and provides many other services to unincorporated areas.