Tsunami Policy Whatcom County and Bellingham

Tsunami Hazard Map for Bellingham Area (Walsh and others, 2004) tsunami_hazard_bellingham.pdf.

I posted previously about tsunami policy in Washington State in general HERE and in Grays Harbor County HERE. My own County of Whatcom includes tsunamis as geologic hazard areas and treats the hazard in a similar manner to volcanic hazards by limiting the types of development and scale of development. Whatcom County has a few susceptible areas that unfortunately from a risk perspective were allowed to develop in a fairly dense manner near the shore. Those locations are sand and gravel spits on the shores of Point Roberts and Sandy Point, some low bank shoreline along the shore of Birch Bay and low areas along the Nooksack River delta and Lummi Peninsula. However, the large tsunami hazard in Whatcom County is nowhere as severe as Grays Harbor and the outer Washington Coast. Residents at the above locations will have a couple hours post Cascadia quake to get to higher ground versus the 20 minutes or so residents at Ocean Park or Long Beach will have. And the depth of waves is not expected to be more than a few feet based on models by Walsh and others tsunami_hazard_bellingham.pdf. Emergency planning has placed signs and sirens particularly at Sandy Point, which has areas that go under water even without a tsunami. Whatcom County also bought a low sand spit area on Point Roberts to preclude development, not so much due to the hazard, but because of the natural setting. The worst area is is in the river delta and the County has been actively buying homes and properties in this area as part of a flood hazard reduction program and development is otherwise fairly sparse in thus flood prone area. Other areas on the map in the delta area are under the control of the Lummi Nation.

Bellingham development code makes no mention of tsunamis in its geologic hazard section of the critical areas regulations. However, with a fair bit of low waterfront property slated for redevelopment, Bellingham and Port officials have developed an environmental impact statement that discusses tsunamis and presumably the issue will be considered as long term redevelopment plans are crafted. The tsunami waves projected for the Bellingham waterfront are modeled to be on the order of a foot or two, so the risk will be fairly minimal and will not require much to mitigate. The seismic response of the hydraulic fill may be another matter of greater concern. And the projected sea-level rise the Port and City are considering may be higher than the moderate number they selected in the environmental impact statement.