FEMA designated Floodplain and Floodway

Aside from a building permit for your project, if your parcel is located with a designated FEMA mapped area, a separate Flood Hazard Determination is required.
If the structure will be located within the FEMA mapped area, a Flood Development review is also required.

Permit fees for Flood Hazard Determination and Flood Plain Development Permits.

1. Construction Drawing:  An elevation certificate is required prior to issuance of your building permit.
2. Building Under Construction:  For construction in flood hazard areas, upon placement of the lowest floor, including basement, and prior to further vertical construction, the building official shall require submission of documentation, prepared and sealed by a registered design professional, of the elevation of the lowest floor, including basement.
3.  Finished construction: Only when all machinery and/or equipment such as furnaces, hot water heaters, heat pumps, air conditioners, and elevators and their associated equipment have been installed and grading around the building is completed.
In conjunction with the International Building Code, provides minimum requirements for development located in flood hazard areas, including the subdivision of land, installation of utilities, placement and replacement of manufactured homes; new construction and repair, reconstruction, rehabilitation or additions to new construction; substantial improvement of existing buildings and structures, including restoration after damage, temporary structures, and temporary or permanent storage, utility and miscellaneous Group U buildings and structures, and certain building work exempt from permit.


The placement of new or replacement manufactured homes is prohibited in floodways under the provisions of RCW 86.16.041 and WAC 173-158-070.  Repairs, reconstruction, replacement, or improvements to existing farmhouse structures located in floodways may be considered under the provisions of WAC 173-158-075.  Repairs, reconstruction, replacement or improvements to substantially damaged residential structures, other than farmhouses, located in floodways may be considered under the provisions of WAC 173-158-076.

Flood Hazard Determination Application

The Flood Hazard Determination Application shall be used when there is not an associated permit like a building permit, manufactured home permit, grading and excavation permit.