Middle Green River Subwatershed
Why is the Middle Green River Important to Salmon?
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.
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, draining Kent, Covington, Maple Valley, and Black Diamond
- Newaukum Creek on the south side of the river, draining the Enumclaw area
The map below shows the Middle Green River subwatershed. View 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 and the cities of Covington, Maple Valley, 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.
Currently Chinook, steelhead, coastal cutthroat, coho, and chum utilize this reach up to the Tacoma Headworks at River Mile 61 for spawning and rearing. During this decade, there have been increasing numbers of pink salmon as well. All species of salmon use this reach of the mainstem for migration and feeding.
Middle Green Subwatershed Facts
Human population: 135,426 (2009 estimate)
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
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.
- Changing the natural flow regime in ways that have harmed salmon;
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.
- Reducing and degrading wetland and riparian functions;
Habitat Information
Water quality information on this stretch of the Green River is available in three reports:
- Water Quality Report 2001-2002 (published May 2004)
- Water Temperature Report 2001-2003 (published June 2004)
- Assessment of Current Water Quantity Conditions in the Green River Basin -- September 2005 (Adobe Acrobat 3.8 MB)
- Figure 1-1 - Location Map (Adobe Acrobat 1 MB)
- Figure 4-1 - Chinook Distribution Map (Adobe Acrobat 1 MB)
- Figure 4-2 - Chum, Coho, Pink, and Sockeye Distribution Map (Adobe Acrobat 1 MB)
More recent water quality data are available at the King County stream monitoring page and the Green-Duwamish Water Quality Assessment.
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.- Big Spring Creek Habitat Acquisition
- Metzler Park Side Channel Habitat Acquisition
- Middle Green River Acquisitions
- Kanaskat North Habitat Acquisition Phase 1
- Kanaskat Reach Acquisition Phase 2
- Kanaskat Reach Acquisition Phase 3
- Lower Newaukum Creek Restoration
- Green River Pautzke Restoration
- Fenster Levee Setback and Floodplain Restoration
Information on the status of individual projects also is tracked on the state's Lead Entity Habitat Work Schedule.
Local Governments in the Middle Green River Subwatershed
Follow the external links to learn more about these communities and what they are doing to improve habitat for salmon. |
Other Organizations/Efforts in the Middle Green River Subwatershed
Green/Duwamish Ecosystem Restoration Project
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 Operations on the Green River (Tacoma Public Utilities)
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
Josh Kahan, 206-296-8052, is the King County basin steward for the Green River, Soos Creek, and Newaukum Creek. Josh is available to work with property owners to help them steward their land and water. Josh also organizes volunteer habitat restoration projects.
Department of Ecology - Green River, Newaukum Creek, and Soos Creek Water Quality Improvement Project
The Washington Department of Ecology is working with local partners on a plan to address warm water temperatures and low dissolved oxygen levels in the Green River and its tributaries. This will result in the development of a Total Maximum Daily Load (TMDL).
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
MSRFEG 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
The coalition works 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.
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.
Lake Sawyer Community Club
The club monitors water quality and educates residents about water quality in the Lake Sawyer Basin.
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
Reconnaissance Assessment Report on the Green/Duwamish and Central Puget Sound Watershed
Comprehensive information on salmon habitat as of 2000. Includes detailed information on on salmon populations, conditions in specific subwatersheds and stream basins, and maps showing salmon habitat.
Green River Watershed Page - King County
Information about the Green/Duwamish River watershed.
Newaukum Creek Basin Characterization - King County
Completed in July 2007, this report describes historic and present conditions, identifies ecological alterations
and knowledge gaps, and anticipates future changes in the Newaukum Creek basin.
The report is intended as a reference document to inform basin management.
Environmental Information Page for WRIA 9 - Washington State Department of Ecology
Includes downloadable publications, maps, and water quality information for Green/Duwamish and Central Puget Sound Watershed (WRIA 9). Most information is related to the Green/Duwamish portion of WRIA 9.
Surf Your Watershed - U.S. Environmental Protection Agency
Site contains links to various U.S. EPA documents related to environmental conditions in the Green/Duwamish watershed. There are links for environmental parameters such as air quality and hazardous waste in addition to water quality.
Green River Hydrograph - U.S. Geological Survey
Interested in how much water is flowing in the Green River right now? This page provides current and historic data on flow for several locations on the Green River.