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Watersheds, rivers and streams

Central Puget Sound

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Central Puget Sound Watershed

Central Puget Sound Watershed

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The Central Puget Sound Watershed of King County includes those areas draining into small creeks that flow directly into Puget Sound including creeks in cities such as Seattle (external), and includes all of Vashon-Maury Island. Other major river basins that ultimately drain from King County into Puget Sound include the Cedar River-Lake Washington Watershed, the Sammamish Watershed, the Snoqualmie-Skykomish Watershed, the Green River Watershed, and the White River Watershed.

For information about the greater Puget Sound Watershed, see US EPA's Puget Sound Watershed page (external link) or our related organizations page. A great map of Puget Sound Watershed is available from the Encyclopedia of Puget Sound (external). For information about the health of Puget Sound marine environment, see our Puget Sound marine topics page.

Introduction to watersheds

Community Service Center
Information about the King County satellite office on Vashon - Maury Island in the Central Puget Sound Watershed.

Puget Sound Partnership (external link)
Public/private group working to develop an aggressive 15-year plan to solve Puget Sound’s most vexing problems.

Puget Sound marine topics
Find studies and plans related to the unique, productive, and diverse marine environment of Central Puget Sound along with news and resources, such as tide tables.

Projects in the Central Puget Sound Watershed

Water and land improvement projects,  Central Puget Sound Watershed
Look up flooding, wastewater treatment and stormwater projects in King County, Washington.

Salmon recovery

WRIA 9 Salmon Recovery - Green/Duwamish and Central Puget Sound
Site provides info about the recovery of threatened salmon species in the Green/Duwamish and Central Puget Sound drainage area including an overview of the planning process, scientific information, and meeting records. We welcome your participation.

Surface water management and groundwater

Report problems: drainage and water quality

Stormwater runoff pollution and how to reduce it
Tips on how to reduce water pollution from home, yard, car, pets and so forth.

Urbanization of Aquatic Systems: Degradation Thresholds, Stormwater Detection and the Limits of Mitigation (Acrobat pdf, external)
Study concluding that "approximately 10 percent effective impervious area in a watershed typically yields demonstrable, and probably irreversible, loss of aquatic-system function."

Lakes: statistics and water quality

Lake Weedwatcher Program
Got a small boat? Interested in saving a lake from the horrors of dense weed infestations?

Beaches, nearshore and marine habitat

Puget Sound Shoreline Stewardship Guidebook
Provides info and contacts for residents of beach and bluff shorelines to learn about natural shoreline protection, manage runoff, use native plants, control aggressive non-native plants, and maintain septic systems in an ecologically friendly way.

Juvenile Salmonid Composition, Timing, Distribution, and Diet in Marine Nearshore Waters of Central Puget Sound in 2001-2002
Scientific report essential to protect and recover Puget Sound salmon stocks.

Spatial Relationships between Beneficial and Detrimental Nearshore Habitat Parameters in WRIA 9 and the City of Seattle (external, Acrobat pdf)
Presents analysis of data from the Marine Shoreline Inventory report and provides linkages between shoreline armoring and loss of riparian vegetation and drift log accumulations.

Inventory and Assessment of Current and Historic Beach Feeding Sources/Erosion and Accretion Areas for the Marine Shorelines of Water Resource Inventory Areas 8 and 9

Marine Shoreline Inventory Report: March 2004
Inventory of selected shoreline habitat features that support juvenile salmonids, presented in part using high-resolution aerial photos with overlays that classify habitat types.

Juvenile Salmonid Composition, Timing, Distribution, and Diet in Marine Nearshore Waters of Central Puget Sound in 2001-2002
Scientific report essential for protecting Puget Sound salmon from extinction and to recover depleted salmon stocks.

Environmental Indicators: Marine Water Quality 
Learn about the condition of King County’s marine waters, how Puget Sound gets polluted, actions by King County and how you can help.

Saltwater Shorelines, Life on the Edge Video Series Includes Video
Watch a video that describes what affects Puget Sound beaches and their habitat, with ideas that beachgoers and shoreline property owners may like to apply to help preserve the quality of saltwater beaches and their ecosystems.

Shoreline Master Program
Learn about King County's program to protect shorelines, promote public access, and establish priorities for shoreline uses along Puget Sound, large lakes, and rivers.

Marine Shoreline Inventory Report
Inventory of selected shoreline habitat features that support juvenile salmonids, presented in part using high-resolution aerial photos with overlays that classify habitat types.

Inventory and Assessment of Current and Historic Beach Feeding Sources/Erosion and Accretion Areas for the Marine Shorelines of Water Resource Inventory Areas 8 and 9
This report examines an important part of the Puget Sound nearshore ecology: the erosion of bluffs and the transport of sediment to feed beaches. It evaluates where bluffs historically eroded, where the erosion occurs today, and evaluates the expected benefits of removing bulkheads in key areas to re-establish the vital process of sediment erosion-transport-deposition.

Puget Sound Tide Tables, courtesy of NOAA


Coastal Areas breakout session results, King County Climate Change Conference
Review a summary report describing anticipated affects of global warming on coastal lands in Washington State with proposed adaptation strategies. Also, look up the coastal area session agenda, presentations, and speaker credentials and biographies.

image of report coverState of the Nearshore Report
The first attempt to provide a comprehensive summary and an assessment of the state of our current knowledge of ecological processes and conditions, natural resources, and ecosystem health in nearshore portions of Water Resource Inventory Areas (WRIAs) 8 and 9.The intent of this report is to have, in one place, a summary of the nearshore ecosystem characteristics in WRIAs 8 and 9 that will serve as a foundation for future technical work and decision making.

Puget Sound Nearshore Environment

Undeveloped Stream Mouth The Puget Sound Nearshore Environment. An illustrated presentation.

Go to Beyond the Beach:
Learn about the Nearshore Environment and what you can do to help protect it from damage.

Plans and restoration projects

Prioritization of Marine Shorelines of WRIA 9 for Juvenile Salmonid Habitat Protection and Restoration
This report brings together biological and geological information to help prioritize where efforts can produce the best results for nearshore habitat improvement, using maps and photos to highlight high quality habitat that should be conserved and damaged habitat that should be restored. Published May 2006.

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

Elliot Bay Nearshore Substrate Enhancement
A status report on a project to restore nearshore habitat by placing cobble, quarry spall, pea gravel and oyster shell at sites near the Duwamish Head and Seacrest.


Elliott Bay and downtown Seattle
Elliott Bay and downtown Seattle

Wastewater treatment system

History of King County's Regional Wastewater Treatment Utility
Read how our region worked to keep our lakes and Puget Sound clean and healthy, including the early days of sewage treatment and disposal in King County, the birth of Metro and development of regional facilities to process the waste produced by our metropolitan area.

West Point Treatment Plant
An overview of King County's West Point wastewater treatment plant on Puget Sound.

Go to Brightwater Treatment Facilities An overview of King County's new Wastewater Treatment plant, a major improvements to the sewage treatment system serving King and Snohomish Counties. The Brightwater project included a new water cleaning plant, its associated conveyance pipes, and a big pipe and outfall to Puget Sound.

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 Puget Sound and other waters to keep it from backing up into homes and businesses. Learn how King County is working to improve our system to control overflows.

Endocrine disrupting chemicals in the environment
Learn about these natural and synthetic chemicals flushed daily into Puget Sound and discover what King County is doing to protect public health and the environment as the science and our understanding of endocrine disruptors develops.

Hidden Lake Pump Station Replacement and Sewer Improvement Project
Shoreline area project to replace an aging pump station and add underground storage of wastewater to reduce sewage overflows into Puget Sound.


Noxious weed infestation map
Interactive map showing location of regulated noxious weed infestations.

Forestry services and information
Find landowner services, advice and help to promote sustainable forestry in King County.

Agriculture in King County, Washington
Find services and resources specifically for farmers in King County, Washington to help agriculture thrive but to minimize environmental damage through common-sense pollution protection and soil conservation.

Basin Steward Program
Look up your basin steward to get help on anything related to the health of lakes, streams or Puget Sound.

Related information

Related agencies

News and announcements

Dec. 7, 2015
External editorial, The News Tribune
Climate change won’t be kind to Puget Sound 

Nov. 5, 2015
External opinion, Seattle Times
Puget Sound recovery hinges on blocking polluted runoff 

Jul. 9, 2015
External article, Washington Post
Why the Earth’s past has scientists so worried about sea level rise  

Jun. 24, 2015
External article, Seattle Times
Conservation groups seek increased shoreline protections in Puget Sound

Jun. 23, 2015
External article, The News Tribune
Acquisition, habitat projects help Puget Sound fish – and people, too 

Jun. 23, 2015
External article, Vashon Beachcomber
Transforming a landscape on Maury

Jun. 6, 2015
External article, Seattle Times
Cleaner streets for cleaner Puget Sound planned

Jun. 4, 2015
External article, Grist
Climate forecast for Seattle: warmer and wetter, with a chance of deluge 

May 20, 2015
External release, Washington Dept. of Ecology
Cleanup proposed at Seattle cargo terminal

May 18, 2015
Local industrial facilities earn recognition for environmental compliance

May 15, 2015
External article, Seattle Times
Inslee declares statewide drought emergency

March 2015
External article, B-town Blog
Family events at the Environmental Science Center at Seahurst Park

Feb. 24, 2015
External article, Seattle Times
Seattle’s new seawall also a highway for fish

Feb. 21, 2015
External column, Seattle Times
To save our Puget Sound orcas, we must save salmon

Feb. 2, 2015
External article, B-Town Blog
Volunteers needed for Walker Preserve Restoration Work Party on Feb. 7

Jan. 20, 2015
External article, Seattle Weekly
King Tide Shows What Climate Change Has In Store

Oct. 7, 2014
External article, Encyclopedia of Puget Sound
Citizens now the leading cause of toxics in Puget Sound

Oct. 6, 2014
External article, SeaTac News
Hundreds gather to celebrate reopening of Seahurst Beach in Burien

Sep. 2, 2014
Help keep tabs on native salmon this fall as a King County Salmon Watcher Program volunteer
Free training sessions offered in Seattle, Bellevue, Renton, Woodinville

Jul. 15, 2014
Motorists: Fix leaks so you ‘Don’t Drip and Drive’
Puget Sound Starts Here offers coupon for free visual leak inspections, repair discount

Jul. 10, 2014
Executive Constantine supports comprehensive approach to improving water quality

Mar. 25, 2014
Watershed group, Burien share Futurewise award for Seahurst Park salmon restoration

Flood reduction grants
Applications due by June 15, 2014

Nov. 7, 2013
Work begins to ID projects that cut pollution for SW King County’s Miller, Walker creeks

Nov. 5, 2013
External, NW Public Radio
Snowpack, Sea Level, And Wildlife Main Climate Change Risks In The Northwest audio

Jun. 12, 2013
Northwest coal terminals: Executive Constantine's letter to the U.S. Army Corps of Engineers (pdf)

May 2, 2013
South Park, Highland Park & West Seattle areas now eligible for RainWise rebates

Apr. 18, 2013
Mayor, County Executive, Port announce deal for water quality improvements and new park at Smith Cove
Deal responds to neighborhood’s desire for new park space 

Jan. 12, 2013
External article, Seattle Times
Seattle calculates how climate change will redraw its shores

Dec. 19, 2012
External report, KING5 News
Monday's high tide hits all-time record video 

Nov. 27, 2012
External article, Crosscut
State unveils ideas on tackling ocean acidification

Nov. 9, 2012
External article, West Seattle Blog
What’s in our waterway? New site dives into Puget Sound pollution

Oct. 18, 2012
King County hosts meeting on Magnolia sewer improvement project, Oct. 20

Oct. 3, 2012
Neighbors' input, technical review guides Barton CSO project design updates

Sept. 12, 2012
County Executive recognizes People for Puget Sound on news it will cease operations this fall

salmon_SEEson_2011_smSee salmon this season.

Sept. 26, 2012
Executive Constantine applauds unanimous vote to adopt long-term pollution control plan

Aug. 8, 2012
External opinion, Seattle Times
Washington steps up fight against polluted runoff

Jun.25, 2012
External report, KPLU
Study: Rising seas will hit Calif. hardest, but Washington still sees damage audio

Jun.23, 2012
External column, Seattle Times
Acidic step: outsourcing our oysters

Jun. 20, 2012
Curbside meetings take Barton CSO project info to West Seattle neighbors, June 23 & 24

Jun. 4, 2012
Employees respond to overflow at Barton Pump Station

May 24, 2012
Community meeting on May 30 highlights West Seattle sewer improvement project

Puget Sound starts here
King County continues its commitment to safeguard Puget Sound and protect human health by joining forces with the newly organized Puget Sound Starts Here campaign.

Puget Sound Partnership on Facebook (external link)
King County WTD, a Clean-Water Agency (external link)

Mar. 22, 2012
Green stormwater infrastructure sites identified for further study in West Seattle
Public meetings on March 28 and 31 offer updates on Barton CSO project

» Archived news and announcements

» Related organizations