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Middle Green River Subwatershed
Green/Duwamish and Central Puget Sound Watershed
Water Resource Inventory Area (WRIA) 9
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Why is the Middle Green Subwatershed Important to Salmon?
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The best salmon habitat remaining in the watershed is found in the Middle Green River subwatershed. Every year, thousands of Chinook salmon spawn in the Green River mainstem and on Newaukum and Soos Creeks. Thousands more coho salmon spawn in tributary streams.
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Subwatershed Salmon Habitat Overview
This subwatershed starts at River Mile 32 just east of Auburn and stretches to River Mile 64.5, the location of Howard Hanson Dam (HHD). It includes two major tributaries: Soos Creek on the north side of the river and Newaukum Creek on the south side of the river.
The map below shows the Middle Green River subwatershed. Click here for a map showing this subwatershed in relation to the rest of the watershed.
While this subwatershed has experienced rapid urbanization during the last two decades, it provides the primary spawning and freshwater rearing areas of the Green/Duwamish and Central Puget Sound Watershed. Most lands near the Green River mainstem are farms, small commercial forests, or parks. Farther from the river are the newer neighborhoods of Kent, the new cities of Covington and Maple Valley, and the older communities of Black Diamond and Enumclaw.
The construction and operation of Howard Hanson Dam (HHD) has substantially reduced the amount of spawning gravel in the Middle Green. Because HHD limits floods, the natural flow regime of the mainstem Green River has been altered, harming habitat as described below. The Tacoma Headworks Dam also currently blocks upstream passage of all salmon.
Middle Green Subwatershed Facts
Human population: 112,000 (1999)
Primary land uses: residential (50%),
commercial forestry (27%), agriculture (12%)
Mean annual discharge:
1,300 to 2,000 cubic feet per second
Salmon species currently present:
Chinook, coho, chum, pink, sockeye, steelhead, coastal cutthroat trout
Additional salmon species thought to be here historically: bull trout
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Currently Chinook, steelhead, coastal cutthroat, coho, and chum utilize this reach up to the Headworks at River Mile 61 for spawning and rearing. There are limited numbers of pink and sockeye salmon as well. All species of salmon use this reach of the mainstem for migration and feeding.
Where the Fish Are in the Middle Green River Subwatershed
Fish distribution maps show where anadromous salmon and trout have been found or should be present.
Problems on the Mainstem Green River
- Dams, levees, and residential and agricultural land use that are:
- Changing the natural flow regime in ways that have harmed salmon;
- Reducing the amount of spawning gravel;
- Reducing the amount and size of large woody debris with a consequent reduction of channel complexity;
- Reducing side channel and other off-channel habitats; and
- Reducing and degrading riparian habitat functions.
Problems on Tributary Streams
- Residential, agricultural, and some urban development that are:
- Reducing and degrading wetland and riparian functions;
- Reducing forest cover and increasing impervious surfaces leading to hydrologic disruption to stream flow, channel degradation, increased sedimentation, and decreased water quality;
- Rechanneling streams and limiting their lateral migration to facilitate roads and protect property;
- Reducing the amount and size of large woody debris;
- Creating barriers to fish passage; and
- Introducing non-native plant and animal species.
Recent Habitat Information
Additional information on the quality of habitat along Green River mainstem in this subwatershed is detailed in the Middle Green River Baseline Habitat Monitoring Report (Adobe Acrobat 15.7 MB) completed in August 2002.
Water quality information on this stretch of the Green River is available in two reports:
More recent water quality data are available at the King County Water Quality Data page.
See also water quality data from the Washington State Department of Ecology.
In July 2007, King County completed a characterization of historic and current conditions on Newaukum Creek.
Project Solutions to These Problems
Projects funded by the Salmon Recovery Funding Board and other grantors are listed here. The projects listed below are only a few of the various projects of governments and volunteer groups in this subwatershed.
Other planned projects in this subwatershed can be located using the WRIA 9 Interactive Work Schedule and Project Portfolio.
Local Governments in the Middle Green River Subwatershed
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Follow the external links to learn more about these communities and what they are doing to improve habitat for salmon.
* Indicates that volunteer opportunities or other specific salmon related information are available on this site.
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Other Organizations/Efforts in the Middle Green River Subwatershed
- Green-Duwamish Ecosystem Restoration Project Page of the U.S. Army Corps of Engineers
The US Army Corps of Engineers, in partnership with King County, the cities of the watershed, the Muckleshoot and Suquamish Tribes, state agencies, and local interests have developed the Green/Duwamish Ecosystem Restoration Project to restore the ecosystem of the watershed. Several projects are in the Middle Green River subwatershed.
- Howard Hanson Dam
Information on the Howard Hanson Dam, constructed in 1962 and operated by the U.S. Army Corps of Engineers for flood protection purposes.
- Tacoma Water
Tacoma Water serves more than 83,000 customers in the cities of Tacoma and University Place, plus portions of Puyallup and Pierce and South King counties. The majority of this water is taken from the Green River. Tacoma operates the diversion dam ("Headworks") at River Mile 61.
- King County Basin Stewards
The King County Water and Land Resources Division has Basin Stewards for specific basins. These stewards:
- Respond to citizen inquiries concerning issues in their part of the watershed
- Coordinate efforts among various public agencies
- Facilitate watershed improvement projects
- Provide assistance to monitoring programs
- Provide public education opportunities
The King County basin steward for the Middle Green River subwatershed, including the Green River mainstem, Soos Creek, and Newaukum Creek, is Josh Kahan, 206-296-8052.
- King Conservation District
Since 1949, the KCD has been helping the people of King County manage their natural resources by educating landowners, schools groups, scientists, consultants and agencies in recognizing problem situations and avoiding the creation of them. KCD also provides technical assistance in solving problems.
- Mid-Sound Regional Fisheries Enhancement Group
MSFEG works to enhance and restore salmon habitat and resources in the Mid-Puget Sound Region -- including the Green/Duwamish and Central Puget Sound watershed -- through community partnerships. MSFEG is particularly active in the Newaukum Creek area in the Middle Green River subwatershed.
- Middle Green River Coalition
This recently-founded group seeks to identify and preserve key natural areas in the Middle Green River Subwatershed. The site includes many photographs of some of the less well-known lakes and streams in this part of the Green/Duwamish watershed.
- Friends of the Green River
This group focuses on protection and water conservation in the Green River watershed, including the Middle Green.
- Green-Duwamish Watershed Alliance
The Alliance is dedicated to the protection and restoration of the Green/Duwamish Watershed through partnerships with communities, tribes, businesses, and government agencies.
- Shadow Lake Bog (SHADOW)
Shadow Lake bog is one of the headwaters of Jenkins Creek in the Soos Creek basin. It is a peat bog whose continued health will benefit salmon by acting as a natural deterrent to flooding. Save Habitat And Diversity Of Wetlands (SHADOW) is devoted to protecting and educating people about this unusual ecosystem in the Green/Duwamish watershed. Volunteers have constructed a boardwalk allowing people to visit the bog without harming it.
- Friends of Soos Creek Park
This group is dedicated to the protection and enhancement of Soos Creek Park, which runs along much of Soos Creek.
- Lake Sawyer Community Club
The club monitors water quality and educates residents about water quality in the Lake Sawyer Basin.
- Lake Meridian Community Association
The association addresses recreational uses, the control of aquatic weeds, and water quality concerns for Lake Meridian, which drains into Soos Creek. It also sponsors community events.
- Rainier Audubon
The mission of the Rainier Audubon is to conserve and restore natural ecosystems and protect birds and other wildlife for the benefit of humanity and biological diversity in South King County.
- South King County Group, Cascade Chapter of the Sierra Club
The Sierra Club works on a variety of environmental issues including water quantity, water quality, and habitat for salmon and other aquatic creatures.
Information Resources for the Middle Green River Subwatershed
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