Flood, Confluence, Issaquah Creek

Warning Systems

Issaquah's Local System

Along with King County's alert system (sign up online), the City of Issaquah posts flood phase information (typically Phase 2 or higher) on its:

Using the upstream gauge in Hobart, Issaquah's Flood Warning System can usually provide three to four hours lead-time (depending on your location and the extent of the flooding).

Hobart Flood Gauge

To see more data of the upstream gauge in Hobart, visit the USGS website. This external site, however, is only updated once an hour. Using this data, King County also issues flood alerts by phone, text or e-mail.

For more up-to-date information, tune in to the City's Flood Warning System.

National Weather Service Forecasts

The National Weather Service also broadcasts flood warnings for Issaquah Creek (along with other rivers in the region) based on its forecasts and/or observations at the downstream gauge near Lake Sammamish State Park. For forecast information, visit the National Weather Service National Oceanic and Atmospheric Administration.

When these warnings occur, residents should also monitor the City's Flood Warning System for current, local conditions.

Issaquah's Flood Phases

PhaseExtent of FloodingAction by CityAction by ResidentsIssaquah Creek Level
  • Insignificant
  • Flood Watch Phase
  • Public Works and Police Department notified
  • Stand-by monitoring begins
  • Always be prepared with household flood strategy
  • Monitor the city's Flood Warning System and weather reports
  • Upstream gauge reads 6.5 feet and rising
  • Heavy rains expected to continue
  • Localized flooding in flood-prone areas
  • A few street closures due to water on roadway
  • Public Works Operations Department begins flood fighting activities
  • Initiate household flood strategy
  • Frequently flooded areas can expect flooding
  • Monitor the city's Flood Warning System and weather reports
  • Upstream gauge reads 7.5 feet and rising
  • Considerable flooding on Issaquah Creek, Tibbetts Creek, and the East Fork of Issaquah Creek
  • Flooding possible in many creekside areas
  • Full flood fighting effort in effect
  • Evacuate if necessary
  • Monitor the city's Flood Warning System and weather reports
  • Block basement drains
  • Upstream gauge reads 8.5 feet regardless of trend
  • Extensive flooding similar to January 2009 or greater throughout Issaquah and Tibbetts Creek Valleys
  • Maximum flood fighting effort in effect
  • City prepares for possible disaster
  • Evacuate if necessary
  • If not, make sure that you are ready to withstand the full extent of the flood with ample supplies
  • Upstream gauge reads 9.0 feet regardless of trend

How to Prepare  Flood Brochure Cover (PDF) Opens in new window 

Sand & Bags

Learn more about sand and bag deliveries.

Localized Flooding

To prevent any localized flooding, residents can help out by keeping the storm drains near their homes clear of debris and leaves.

For larger stormwater issues, call the Public Works Department at 425-837-3470.

Flood Maps & Insurance

Find out if you are located in a floodplain, and how to get flood insurance.