Green - Duwamish River Watershed

The Green River Watershed is the land area where rainwater drains to the Green-Duwamish River. The watershed includes Black River, Springbrook Creek, Mill Creek, Soos Creek, Jenkins and Covington Creeks, Newaukum Creek, Crisp Creek, and other tributaries. This page provides services and information in the Green-Duwamish Watershed while information spanning multiple watersheds may be found on our King County watersheds page.

For information about the area that is a source for City of Tacoma's drinking water, please see Tacoma Public Utility's Green River Watershed page.

Introduction to watersheds

Basin Steward Program
Find out what Water and Land Resources' Basin Steward Program does and how to contact your Basin Stewards.

Flooding and hydrology

Green River flooding information
Look up real time gage data, flood phase/ river crest descriptions and learn what high water means to you along the Green-Duwamish River.

Historic flood photo viewer
Use a map to look up aerial photos of past floods on the Green River and other rivers in King County.

Hydrologic gage data map
Look up detailed gaging station data from area creeks and rivers.

Salmon recovery

WRIA 9 salmon recovery:
Green/Duwamish River
Site provides status and actions to recover of threatened salmon species in the Green/Duwamish drainage area including an overview of the planning process, scientific findings, and meeting records.

Salmon recovery by sub-watershed

• Duwamish Estuary
• Lower Green River
• Middle Green River
• Upper Green River

The Restore and Protect Project
Project to identify habitat stressors and recommend restoration and protection actions to improve freshwater quality and aquatic habitat in Puget Sound streams including Soos, Cristy and Newaukum Creeks in the Green River Watershed.

Surface water and groundwater

Report problems: drainage and water quality 

Stormwater runoff pollution and how to reduce it
Rainstorms rinse the watershed faster when covered by hard surfaces like roofs and roads.  Learn how stormwater brings pollution, wastes and sediments into streams, rivers and lakes and how you can keep stormwater clean.

How you can help the Duwamish
https://kingcounty.gov/en/dept/dnrp/waste-services/wastewater-treatment/programs/duwamish-waterway/how-you-can-help

Green-Duwamish River watershed map (941 Kb)
Drainage map displaying streams, lakes, drainage divides, and major roads in the area that drains to the Duwamish waterway and into Elliott Bay.

• Hamm Creek aerial photo map (1.4 Mb Acrobat pdf)
  Detailed map showing drainage and open channels for Hamm Creek as of 1998.

Lakes in the Green River/Duwamish Watershed

• Angle Lake
• Clark Lake
• Deep Lake
• Lake Dolloff
• Lake Fenwick
• Lake Geneva
• Grass Lake
• Horseshoe Lake
• Jones Lake
• Lake Lucerne
• Lake Meridian
• Lake Morton
• Lake Neilson (Holm)
• North Lake
• Panther Lake
• Pipe Lake
• Ravensdale Lake
• Lake Retreat
• Lake Sawyer
• Star Lake
• Walker Lake
• Lake Wilderness

Pollution monitoring and control

Ongoing water quality sampling in the Duwamish Waterway, Green River and tributary creeks. Current water quality data are available for:

• Crisp Creek
• Green - Duwamish River
• Longfellow Creek
• Mill Creek
• Newaukum Creek
• Soos, Jenikins and Covington Creeks
• Springbrook Creek

South Treatment plant
An overview of King County's wastewater treatment plant on the Duwamish River

Georgetown Wet Weather Treatment Station
Facility reduces water pollution and improves aquatic habitat and the overall water quality of the Duwamish River.

King County is protecting our waters
During heavy rainstorms, our combined sewers may exceed their capacity and the mixture of untreated sewage and stormwater is allowed to overflow into the Duwamish River and other water bodies to keep it from backing up into homes and businesses. Learn how King County is working to improve our system to control overflows.

• Combined sewer overflow real-time map- Seattle area
  Includes the Duwamish Waterway.

Duwamish Waterway superfund cleanup programs
Accomplishments to restore the Duwamish Waterway, timeline, major milestones, approaches and participants, and how to prevent future pollution.

Sediment remediation projects
Cleanup of contaminated sites in the Duwamish Waterway and Elliott Bay to enhance and restore habitat for aquatic life.

Recreation and appreciation

Natural areas

Look up individual properties protected in King County's open space system for their ecological and working resource values. The natural lands site provides addresses, pictures, location maps and rules for public use:

• Auburn Narrows Natural Area
• Bass Lake Natural Area
• Big Spring Creek/Newaukum Creek Natural Area
• Bingaman Pond Natural Area
• Black Diamond Open Space
• Covington Natural Area
• Flaming Geyser Natural Area
• Green River Natural Area
• Hatchery Natural Area
• Hamm Creek Natural Area
• Horsehead Bend Natural Area
• Kanaskat Natural Area
• Little Soos Creek Wetlands Natural Area
• McGarvey Natural Area
• Neely Bridge Natural Area
• Porter Levee Natural Area

Trails

Interurban trail
The Interurban Trail is a historic rail line that runs 14 miles through Tukwila, Kent, Auburn, Algona and Pacific.

Green River trail
The Green River Trail runs 19 miles and provides excellent views and access to the Green River and surrounding river valley from Cecil Moses Park near Seattle to North Green River Park in Kent.

Soos Creek trail
The Soos Creek Trail features a gentle grade in a natural setting suitable for leisurely strolls, bicycle rides and horse rides.

Publications

Green-Duwamish River Watershed science documents