Flooding services and information

How to prepare for a flood
Learn what to do before, during and after a flood. Look up, locate, and order flood hazard maps. Print the page and keep it on hand just in case.

• Important emergency phone numbers and resources
• Sandbagging lesson slideshow

Flood Warning System
Look up real-time river levels and flow data for the Snoqualmie River, Tolt River, Skykomish River, Raging River, Issaquah Creek, Cedar River, Green River, and White River and learn what local flooding homeowners might expect at different flood phases based on past flood events. This site also links to alerts and warnings from the National Weather service and provides maps of rivers and creeks.

Road conditions and closures
Look up current information about damaged and closed roads in King County.

Report a water quality or drainage problem
Use the phone number or an online form to request an investigation into water quality and drainage problems in King County. This page also contains background information to help residents understand how problems are handled.

Green River flood preparation
Fact sheets, preparation checklists and background information for residents to prepare for increased risk of flooding in the Green River Valley over the winter of 2009-2010.

Video: Winter flooding, 2008-2009 season (external link, 44.47 min.)
Get Windows Media Player (external link) needed to watch this video.
Learn how storms and weather affected King County last winter (2008-2009) and how King County responds to flood emergencies.

An examination of levee vegetation policy
Video of Ron Sims keynote speech to the U.S. Army Corps of Engineers’ Seattle district levee vegetation policy symposium, presented on February 26, 2009.
Windows Media format, video length 47 minutes, 23 seconds
Text transcript, An examination of levee vegetation policy

Flood safety - King County performance measures
These measures combine the National Flood Insurance Program's Community Rating System value with progress King County makes in implementing the levee and revetment improvement projects and flood reduction activities.

The connection between floodplains and the economy
Learn about the economic effects of flooding on King County businesses and the region's overall economy.

Watch Video:
Preventing flood disasters, (22.22 min.)
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King County is at work repairing levees.

King County Flood Control District
Learn about the purpose, governance structure and schedule of activities for this recently established flood management district.

2006 King County Flood Hazard Management Plan
The 2006 King County Flood Hazard Management Plan sets forth a ten-year strategy for how King County proposes to manage its rivers and floodplains to minimize flooding and channel migration hazards throughout the county. The 2006 Plan establishes policy, program and project recommendations to improve public health and safety, and to minimize risks to people, property, roads, public infrastructure, and natural resources. The 2006 Plan does not propose any changes to current flood hazard regulations.

Community Rating System
Learn about a National Flood Insurance Program (NFIP) incentive program that encourages communities to accurately assess risks and reduce flood losses, and rewards better flood management with reduced insurance premiums for its residents.

Floodplain mapping
Review the latest floodplain boundaries in King County and look up or order maps from various sources.

King County Code >> Critical Areas (Acrobat PDF format)
County definitions and rules on development standards, restrictions, and requirements as well as permitted uses in King County floodplains and other sensitive areas. Codes pertaining specifically to floodplains can be found under sections 21A.24.230 to 21A.24.275 of this document.

King County Climate Change Plan
How King County seeks to reduce greenhouse gas emissions, adapt to projected climate change impacts, and embed mitigation and adaptation into county policy decisions. The plan incorporates issues, goals and actions related to flooding.

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

Water-related sensitive areas - interactive map
Note: this link will open a new browser window
Pick the King County map layers you want and click the "refresh map" button located at at the bottom of the layers list to display floodways, 100-year floodplains, channel migration hazard areas, parcels and other map-based information. Viewing information about individual map features may take some practice: choose the "active" (or queryable) map layer from the layers list, select the tool, and click on one of that layer's features to display associated data.

Stormwater facilities, projects and studies - interactive map
Note: this link will open a new browser window
Zoom in to view the full set of GIS layers including the regional, commercial and residential stormwater facilities, neighborhood drainage projects, stormwater studies, and aerial imagery among other things. Viewing information about individual map features may take some practice: choose the "active" (or queryable) map layer from the layers list, select the tool, and click on one of that layer's features to display associated data.

Flood Buyout and Home Elevation Program
This page answers frequently asked questions about King County's program to buy houses located in floodplains or provide homeowner assistance in having homes elevated. The page also provides information about related programs that can help homeowners affected by flooding.

Snoqualmie flood-farm task force report
Provides finding and recommended mechanisms to help Snoqualmie Valley farms that get periodically flooded, in ways that maintain good floodplain management and continue salmon recovery in the lower Snoqualmie River.

• Construction of farm pads on Snoqualmie Valley farms
  Notice of determination of non-significance under the State Environmental Policy Act (SEPA)

City of Snoqualmie hazard mitigation planning (external link)
Find public process documents for an update to the city's 2003 multi-hazard mitigation plan including meeting agendas, minutes, and documents including some covering flood mitigation.

Shoreline management
Learn about King County's program to protect shorelines, promote public access, and establish priorities for shoreline uses along shorelines and flood areas of county's large rivers.

Hydrologic Information Center
This page provides local rain and stream gage data and flood reports for King County river basins including the Cedar River, Snoqualmie River, Issaquah Creek, Bear Creek, and Green River Basins. The page provides current information about water levels as well as reports about flooding in years past.

Take Winter by Storm
Find breaking storm news and a directory of resources for Seattle-King County residents.

Stormwater retention/detention (R/D) facilities
Learn why King County requires, maintains and inspects facilities that catch and slowly release stormwater that drains from our residential areas.

Lower Tolt River Floodplain Restoration Project
Overview of a habitat restoration project designed to return the lower Tolt River to its historic meandering state and rich habitat diversity while continuing to provide flood protection and park uses.

Combined Sewer Overflow (CSO) Control Program
Learn what King County is doing to eliminate the discharge of raw sewage that may result from stormwater exceeding the capacity of combined sewers, and read a map showing where such discharges may occur.

Erosion control for construction sites
This page provides information for about how to prevent runoff at construction sites during the wet season, from the Dept of Development and Environmental Services.

Erosion and sediment control standards
Appendix D of the King County Surface Water Design Manual. 1 MB Adobe Acrobat file.

Natural hazards: flooding
This page is published by the King County Office of Emergency Management. The page provides background information about flooding in King County, including background flooding information, history, vulnerabilities and effects.

Flood damage prevention and cleanup
Compendium of authoritative resources for preventing and repairing flood damage, from the Librarian's Index to the Internet.