The Sammamish watershed is part of the greater Lake Washington - Cedar River drainage, encompassing the land area in which rainwater drains to Lake Sammamish, Bear Creek, the Sammamish River and out into Lake Washington.
Community service center
Information about King County's satellite offices including the Issaquah Community Center in the Sammamish Watershed. Office address is 5415 220th Ave SE (inside the Issaquah District Court building), phone number 206-477-2169.
Brightwater Education and Community Center
New sustainably-built facility and surrounding park located near Bothell and Woodinville, available host school and community events, indoors or outdoors.
Look up watershed experts to get answers to questions and help solve watershed related problems. For more information about the Sammamish Watershed, or to get involved in basin activities contact one of the Basin Stewards in the Sammamish Watershed:
- Issaquah Creek and Bear Creek
Tom Beavers, 206-205-5620
Projects in the Sammamish Watershed
Water and land improvement projects, Sammamish Watershed
Look up flooding, wastewater treatment and stormwater projects in King County, Washington.
Surface water and groundwater
Introduction to watersheds
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.
Learn about the history of the lake including its past and current pollution problems, kokanee populations and what King County is doing to protect the lake.
- Lake Sammamish water quality data
This page offers an overview of Lake Sammamish water quality issues and provides graphs of water quality data from several sampling locations on the lake, spanning years. Graphs display temperature, dissolved oxygen, pH, conductivity, nitrogen, phosphorus, chlorophyll, bacteria, transparency, and other data.
Swimming beach data
Find information about levels of bacterial pollution and relative health risks at swimming beaches on Lake Washington, Lake Sammamish and other King County lakes.
Rivers and streams: ongoing water quality sampling in Sammamish Watershed streams and rivers. Water quality data are available online for:
Lakes: statistics and water quality
Lake Weedwatcher Program
Got a small boat? Interested in saving a lake from the horrors of dense weed infestations?
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.
Redmond-Bear Creek Valley Groundwater Management Area
Issaquah Valley Groundwater Management Area
Learn about plans to protect the aquifer in areas spanning the Sammamish watershed including Woodinville, Redmond, Sammamish, Issaquah and areas in between.
Bear Creek Basin Plan
Assessed the condition in Bear Creek drainage basin, predicted future changes based on development pattern and recommended ways to reduce flooding, erosion and sedimentation in the stream and to protect valuable stream, wetland and fishery habitat.
Issaquah Creek Basin Current/Future Conditions & Source Identification Report
Analysis of the area draining to Issaquah and Tibbetts Creeks, documenting conditions of surface waters and identifying sources of pollution. Published in 1991.
Issaquah Creek Basin and NonPoint Action Plan
Recommendations to manage flooding, pollution and aquatic habitat in Issaquah Creek and its tributary streams. Published in 1994.
Allen Lake Outlet project
Engineering project to relieve area residents of disruptive flooding around the outlet of Allen Lake, to enable reliable access to nearby homes.
Sediment quality evaluation in Lake Sammamish, Lake Union, and Lake Washington
Report of chemical and biological substances, their distribution and toxicity, and benthic communities at various sample sites.
Major Lakes Continuous Temperature Study
Describes results of continuous temperature monitoring in Lake Washington, Lake Union and Lake Sammamish to help understand aquatic ecosystem response to the changing climate.
Development of 3-D Hydrodynamic Model of Lake Sammamish
Describes the development, modifications, calibration, and testing of an abstract model to analyze and understand Lake Sammamish.
Sammamish River Diel pH and DO Study
This study provides data to support the identification of dissolved oxygen, pH and temperature problems in the Sammamish River that affect its aquatic life. The data will also support the development of water quality modeling tools that can be used to evaluate various management options proposed to mitigate problems.
Development of a Water Quality Model of the Sammamish River
Describes the development, modifications, calibration, and testing of the Sammamish River model.
Sammamish Watershed map
Drainage map displaying streams, lakes, drainage divides, major roads, in King County and Snohomish County portions of the Sammamish River Watershed. The map is inAcrobatformat. File size is426 Kb.
Issaquah Creek map
Lake Sammamish kokanee
Describes the dwindling population of genetically distinct kokanee in Lake Sammamish and actions that King County and other agencies are doing to protect and restore them.
Lake Sammamish Urban Wildlife Refuge Partnership New!
Extensive effort to support conservation of fish and wildlife in the Sammamish Basin, and contribute to the quality of life for current residents and future generations.
Sammamish kokanee video, fall 2012
In this video, kokanee salmon return to Laughing Jacobs Creek in large numbers.
Salmon Watcher monitoring sites map
See the sites in Sammamish Watershed and consider volunteering to be a Salmon Watcher next fall.
Lake Washington, Cedar River and Sammamish (WRIA 8) salmon recovery
This site provides information about the recovery of threatened salmon species in the Sammamish, Lake Washington, and Cedar River drainage area including an overview of the planning process, scientific information, and meeting records. We welcome your participation.
Greening your Shoreline
References and recipes for lakeshore property owners on Lake Sammamish and Lake Washington to use to improve shorelines for people and salmon.
Predicting Climate Change Effects on Kokanee Habitat Suitability in Lake Sammamish New!
Report on the application of 2-D and 3-D temperature models of Lake Sammamish to evaluate future climate change impacts on kokanee habitat.
Water Resource Inventory Area (WRIA) 8 plans, studies and maps
- Final WRIA 8 chinook salmon conservation plan
Cedar River, Sammamish, Lake Washington
- Chinook Conservation Plan Implementation Progress Report, 2011
State of the Chinook salmon populations, the watershed, and efforts to implement the WRIA 8 Chinook Conservation Plan during the first five years (2005-2010).
- WRIA 8 Land Cover Change Analysis, 2011 (2.3 Mb Acrobatpdf)
- Known freshwater distribution of salmon and trout
Draft maps showing chinook, coho, cutthroat trout, kokanee, sockeye, and steelhead distribution in the greater Lake Washington watershed (WRIA 8), based on the collective personal knowledge of resource professionals and data gathered from published and unpublished databases.
Flooding and hydrology
Issaquah Creek flood information
View real-time gage data and map for Issaquah Creek and learn about expected conditions at various flood phases.
Hydrologic gage data map
Look up detailed gaging station data for creeks in the region.
Lake Allen Outlet Project
Culvert work to alleviate roadway flooding.
Brightwater treatment system
Major improvements to the sewage treatment system serving King and Snohomish Counties. The Brightwater project encompasses a new treatment plant located in Woodinville, its associated conveyance pipes, outfall to Puget Sound and an environmental education center. The system is under construction now (2011).
Recreation and appreciation
Swimming beach data - water temperature, bacteria and algal toxin measurements
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:
Nature at Brightwater Center
Sammamish Valley tourism & recreation map guide
Outdoor recreation opportunities and points of interest for residents and visitors around Redmond and Woodinville, Washington.
East Lake Sammamish Trail
This scenic and safe regional trail hugs Lake Sammamish and runs from the city of Issaquah to Redmond, connecting Lake Sammamish State Park at the south end with King County's Marymoor Park at the north end of Lake Sammamish.
Sammamish River Trail
King County's beloved regional trail hugs Lake Washington and the Sammamish River to provide a link between the Cities of Seattle, Lake Forest Park, Bothell, Redmond and the crown jewel of our parks system, Marymoor Park.
The largest and most diverse destination park in King County's portfolio of Parks. Provides hundreds of acres of nature and offers a wide variety of recreation options including birdwatching, rock climbing, fishing, off-leash dog walking, bike racing, team sports, outdoor concerts and movies and just being.
Fishing regulations and seasons (external link)
Washington Dept. of Fish and Wildlife fishing rules for Washington State including Sammamish River, Lake Sammamish and their tributaries, and lakes within the watershed.
Known hazards on King County rivers
Reports of confirmed logjams and obstructions that pose a hazard to recreational river users, but does not include hazards that are not known.
Lake Shorelines, Life on the Edge Video Series
Watch a video that describes lakes in King County and how residents value them, with ideas that shoreline landowners may like to apply to help preserve the quality of lakes and lake ecosystems.
Historic and recent aerial photographs
Aerial photos from the 1930's, 1970's, and 1990's illustrating growth around Cottage Lake, among other areas in King County.
Quality assurance project plan for regulatory effectiveness monitoring for developing rural areas
Framework to monitor and evaluate land use regulations to help ensure their effectiveness, using indicators for hydrology, water quality, biology, and stream complexity.
Redmond Ridge, Trilogy and Redmond Ridge East Urban Planned Developments
News and information about these planned developments which together cover several square miles west of Snoqualmie Valley in Bear Creek basin located in the northern Sammamish watershed.
Noxious weed infestation map
Interactive map showing location of regulated noxious weed infestations.
Agriculture in King County, Washington
Comprehensive information related to agriculture in King County including parts of the Sammamish Watershed.
Science documents - Sammamish Watershed
For more information about the Sammamish Watershed, please contact Tom Beavers, Cedar River/Bear and Issaquah Watershed Steward, King County Water and Land Resources Division.