Floodplain Maps

The Federal Emergency Management Agency (FEMA) issues maps that are used to review development projects in the floodplain, and set flood insurance rates.

How to Get Floodplain Maps

Maps are available from the following sources:

• Maps can be printed or purchased online from FEMA.
• Visit King County's online iMAP (select "100-Year Floodplain in the layers)
• Scanned copies can be downloaded below.

Scanned Copies

Flood Insurance Rate Maps (FIRMs)

These maps cover large areas and often can't be used to identify whether a specific property is in the floodplain. All areas of the City that have mapped flood hazard areas are shown, including Issaquah Creek, East Fork Issaquah Creek, North Fork Issaquah Creek, Tibbetts Creek and Lake Sammamish. These maps incorporate the 2002 Issaquah Creek Flood Insurance Study (FIS) update, and are effective as of April 19, 2005.

• Index page (PDF) (2005)
• Panel 680F (PDF) - Lake Sammamish, Greenwood Point (1995)
• Panel 685F (PDF) - Lake Sammamish, East Lake Sammamish Parkway (1995)
• Panel 687F (PDF) - Tibbetts Creek (1995). This map is amended by several LOMRs; see below.
• Panel 691H (PDF) - North West quarter of valley (2005). This map is amended by the East Fork AO Zone LOMR and the Juniper Bridge LOMR; see below.
• Panel 692H (PDF) - North East quarter of valley (2005). This map is amended by the East Fork AO Zone LOMR; see below.
• Panel 693H (PDF) - South West quarter of valley (2005)
• Panel 694H (PDF) - South East quarter of valley (2005)

FEMA Work Maps

These maps - which correspond to the FIRMs and show greater detail for floodplain areas on Issaquah Creek, East Fork Issaquah Creek, and North Fork Issaquah Creek - are available in CAD format. They are also known as the Montgomery Water Group maps for the 2002 FIS update, and include subsequent LOMRs.

• Figure 1 - Lower Issaquah Creek Work Map (PDF) (downstream of Juniper Street)
• Figure 2 - Middle Issaquah Creek Work Map (PDF) (Juniper Street to Newport Way)
• Figure 3 - Upper Issaquah Creek Work Map (PDF) (upstream of Newport Way, including East Fork AO Zone LOMR revisions)
• Figure 4 - East Fork Issaquah Creek Work Map (PDF) (includes East Fork AO Zone LOMR revisions from 2006)
• North Fork Issaquah Creek Work Map (PDF) (1995 North Fork LMMP Study)

Letter of Map Revisions (LOMRs) 

These maps are used to document interim changes to FIRMs (such as floodplain improvement projects or corrections to the original FIRMs).

• Issaquah Creek Lewis Lane Area LOMR (PDF) - 5/31/06
• Tibbetts Creek at I-90 LOMR (PDF) - 6/13/07
• Issaquah Creek at Juniper Bridge LOMR (PDF) - 3/27/07
• East Fork AO Zone LOMR (PDF) - 8/25/06 (south of East Fork)
• East Fork AO Zone LOMR (PDF) - 11/16/06 (north of East Fork along Crescent Drive)
• Upper Tibbetts Creek LOMR (PDF) - 1/24/04
• Lower Tibbetts Creek LOMR (PDF) - 2/23/05

Letter of Map Amendments (LOMAs) 

These maps are used by FEMA to make floodplain determinations on individual properties, as requested by property owners. If the FIRMs doesn't clearly show your property, then in most cases you will need to submit a LOMA to FEMA for their review. A LOMA typically requires elevation data on your property that is prepared by a professional surveyor.

LOMAs can be obtained on FEMA's website, and the City may have copies in our permitting files.

Maps for Older Buildings

To obtain copies of earlier FIRMs that are now out-of-date, but can be used for "grandfathered" flood insurance rates, please contact the City. Maps were issued in 1980, 1989, 1995, and 1998. For pre-1980 buildings (known as "pre-FIRM" buildings), there are no maps for flood insurance purposes because floodplain regulations in Issaquah didn't exist prior to that time.