Civil/Structural Engineering, Vashon, Washington, USA 206-463-5311

Coastal Floodplain Designation


Homeowners buying, remodeling or re-financing a home in a newly designated Coastal Floodplain, must purchase flood insurance unless they can provide documentation that the first floor of the house is 3' above Base Flood Elevation.  Ellisport Engineering can help you by establishing your Base Flood Elevation and complete the FEMA forms to grant you a flood insurance exemption. Save money on flood insurance  by calling us today. 

Coastal Floodplain Designation

King County waterfront property owners have been surprised by the recent inclusion of their properties within coastal floodplains. Puget Sound coastal and near-coastal homeowners need to be aware of new restrictions and limitations to their property:


  • Much of the populated Puget Sound shorelines has been designated coastal floodplains, including new floodplain maps for Vashon Island.  Homeowners in these floodplain areas may be required to carry flood insurance.
  • The floodplain designation also includes severe restrictions for new shoreline construction and for remodeling of existing structures.


If you intend to buy, remodel or re-finance a home designated in a floodplain, you will be faced with purchasing flood insurance, unless you can provide documentation that the first floor of the property is 3 feet above the Base Flood Elevation.  Flood insurance can be expensive.  Ellisport Engineering can work with you to determine your floor elevation.  Specifically, our engineers will work with you to resolve your floodplain issues by:

  • Helping you understand the ramifications of owning a house in a designated floodplain.

  • Determining your house’s first floor elevation relative to the Base Flood Elevation for your location.
  • Filing the proper FEMA paperwork so your house can be removed from the floodplain designation and you can avoid paying for flood insurance.

  • If your house’s first floor is below the BFE, then we can discuss your options: raise the house, vacate the lower story and use for storage, move the house to higher ground.  There are options, often more affordable than you might think.

  • If you plan on building or remodeling in the floodplain, there are special foundation requirements, breakaway walls, and other design considerations.  Here too, we can help.

To learn more, click on the following page links on our website:  Floodplain BackgroundFlood Insurance,Building in a Floodplain , and Important Web Links , then give us a call at 206-463-5311 to see how we may help you save money on flood insurance.