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Sammamish Watershed

Information and services within the drainage area that flows to the Sammamish River and into Lake Washington. Includes lakes, streams, wetlands, fish and wildlife habitat, pollution, flooding, open space, and agricutlure in the area.

Lake Sammamish view

The Sammamish watershed is part of the greater Lake Washington - Cedar River drainage, encompassing the land area in which rainwater drains to Lake SammamishBear Creek, the Sammamish River and out into Lake Washington.

Introduction to watersheds

Basin Steward Program
Find out what Water and Land Resources' Basin Steward Program does and how to contact your Basin Stewards.

Surface water and groundwater

Report problems: drainage and water quality

Stormwater runoff pollution and how to reduce it
Rainstorms rinse the watershed faster when covered by hard surfaces like roofs and roads.  Learn how stormwater brings pollution, wastes and sediments into streams, rivers and lakes and how you can keep stormwater clean.

  • 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.

The Restore and Protect Project
Project to identify habitat stressors and recommend restoration and protection actions to improve freshwater quality and aquatic habitat in Puget Sound streams including Stensland and Tibbetts Creeks in the Sammamish Watershed.

Pollution monitoring

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

Salmon recovery

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
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.

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 can use to improve shorelines for people and salmon.

Water Resource Inventory Area (WRIA) 8 plans, studies and maps

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 Sammamish flooding frequently asked questions (FAQs)
Find answers to questions about flooding near Lake Sammamish.

Wastewater treatment

Brightwater Treatment Plant
Regional clean water factory that treats wastewater from homes, schools, businesses and industries in north King County and south Snohomish County. The plant design integrates landscape, architecture, wildlife habitat, engineering, art, and education.

Recreation and appreciation

Brightwater Education and Community Center
Sustainably-built facility and surrounding park located near Bothell and Woodinville, available to host school and community events, indoors or outdoors.

Salmon SEEson - salmon viewing
Look up locations to view the fall migration of salmon returning to native streams in the greater Lake Washington Watershed and Central Puget Sound drainages.

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.

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:

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.

West Sammamish River Trail
Quiet gravel trail in Redmond used by walkers, runners and fat tire bikers and offering casual side loops.

Burke Gilman Trail
Regional trail runs for Golden Gardens Park in Seattle, past Lake Union and the University of Washington, along Lake Washington to Bothell, where the trail links to the Sammamish River Trail, opening muscle-powered access to King County's eastside.

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.

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.

Lands

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.

Publications

Science documents - Sammamish Watershed

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