Number of Dams: Two -
- Howard Hanson Dam, Built 1962 and
- Tacoma Water Supply Diversion Dam, Built 1911
Contact us
For help with services in the Green River watershed or to report a problem, please call or email: Josh Kahan, Green River Basin Steward at 206-296-8052. For Newaukum Creek, contact Tom Beavers at 206-205-5620.
Wastewater Treatment
South Treatment Plant
An overview of King County's wastewater treatment plant on the Duwamish River.
Soos Creek Sewer Improvement
Increased capacity to help meet growing demands for sewer service in Covington, Maple Valley and Black Diamond.
Pacific Pump Station Replacement Project
Overview of a plan to replace a worn-out pump station in the City of Pacifc and add capacity.
Combined Sewer Overflow Control Program
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.
Flooding and Hydrology
Green River Flooding Information
Look up real time gage data, flood stage info and learn what it means along the Green-Duwamish River.
Hydrologic Gage Data Map
Look up detailed gaging station data from area creeks and rivers.
Surface Water and Groundwater
Green-Duwamish River Watershed Map
Drainage map displaying streams, lakes, drainage divides, and major roads in the area that drains to the Duwamish waterway and into Elliott Bay. The map is in Acrobat format. File size is 941 Kb.
South King County Groundwater Management Area
Learn about plans to protect the aquifer in the south county area including the Green-Duwamish watershed localities of Renton, Kent, Auburn, Covington, Black Diamond, Maple Valley, Tukwila, and areas in between.
Watch Video:
Preventing flood disasters
King County is at work this summer repairing levees
RealPlayer needed to watch this video.
Video length 22 minutes, 22 seconds.
Green-Duwamish River Watershed Quality Assessment
Comprehensive study of the Green-Duwamish River water quality and the land area draining to it, to help guide policy, prioritize cleanup and restoration efforts, and protect salmon stocks from depletion.
Combined Sewer Overflow Water Quality Assessment
Analysis of water and sediment quality in the Duwamish River and Elliott Bay to use as a basis for cleanup and restoration projects.
Streams Monitoring Program
Keeping watch for pollution in the Duwamish Waterway, Green River and tributary creeks. Water quality data are available online for:
Endocrine disrupting chemicals in the environment
Learn about these natural and synthetic chemicals flushed daily into our waters, and discover what King County is doing to protect public health and the environment as the science and our understanding of endocrine disruptors develops.
2004 Rural Drainage Program Expenditures and Accomplishments
Desribes accomplishments and expenditures of King County's Surface Water Management Program on Vashon-Maury Island, the Enumclaw Plateau, and Snoqualmie Valley.
Combined Sewer Overflow Control Program
Info about CSO outfalls located on Puget Sound, Lake Washington, Lake Union, and the Duwamish River including how they're monitored, reduced, and eliminated.
Norfolk Cleanup Project
Information about an effort to remove contaminated sediments from the Duwamish River to enhance and restore the river habitat.
Salmon & Trout Recovery
WRIA 9 Salmon Recovery:
Green/Duwamish River
This page provides information about the recovery of threatened salmon species in the Green/Duwamish drainage area including an overview of the planning process, scientific information, and meeting records. We welcome your participation.
Newaukum Creek Basin Characterization Project Report NEW!
Describes the condition of Newaukum Creek, identifies ecological problems to inform restoration priorities, enumerates knowledge gaps to resolve, and anticipates how conditions in the creek may change in the future.
Green Duwamish River Ecosystem Restoration (external pdf)
A federal Interagency partnership to recognize excellence in designing and implementing exemplary stream corridor restoration projects that improve water quality, the natural environment, and the local community.
This publication includes an overview of the Green/Duwamish River watershed, findings of the Ecosystem Restoration Study, and recommendations for action. To view this publication, you will need Acrobat installed on your computer. File size is 379 Kb and will take approximately 1.1 minutes to download on a 56 Kb/sec modem.
Recreation and Appreciation
King County 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:
Interurban Trail
Green River Trail
The Interurban and Green River Trails will comprise a system of 46 miles. The Interurban Trail currently covers 14 miles from I-405 in Tukwila to 3rd Ave SW, just south of Pacific. The Green River Trail will span 30 miles from Seattle's Alki Point to King County's Auburn Narrows Park. Its completed sections traverse the industrial heart of the valley from south Seattle through Kent, connecting to a number of neighborhoods and community trails.
Soos Creek Trail
The Soos Creek Trail features a gentle grade in a natural setting suitable for leisurely strolls, bicycle rides and horse rides. To find out more about this unique resource, the King County Park System offers a variety of interpretive programs and volunteer opportunities for interested trail users.
Boating on the Green River: review our flooding & habitat project locations, and hyperlink to the boaters page for safety tips, boating signals, and other useful info.
Lands
Forestry
Comprehensive information related to forestry across King County including parts of the Green River Watershed.
Agriculture Topics
Comprehensive information related to agriculture in King County including parts of the Green River Watershed.
Community Supported Agriculture Farms
Historic and Recent Aerial Photographs
Aerial photos from the 1930's, 1970's and 1990's illustrating growth around Lake Meridian in the Soos Creek drainage, among other areas in King County.