Tuesday, March 29, 2011

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.

9 comments:

Ryan M. Ferris said...

Try this document:

http://www.usfa.dhs.gov/pdf/efop/efo39319.pdf

It says some estimates show 20 - 30' waves hitting Bellingham.

We are not ready in Whatcom County! We are building sea level development on shaky ground, putting piles of coal on long piers, building a walkable pier to down town and most of the county has 0 ("zero") idea what to do or where to go if a 9.1 hits the Cascadia Subduction Zone. Remember, in 1700 such an event sent waves as high 30' across the Pacific and destroyed parts of Japan. See:

http://pubs.usgs.gov/pp/pp1707/pp1707.pdf

There are no Tsunami warning signs, no public evacuation routes are ever discussed, I don't ever here this brought up as part of water front planning or regional planning, etc...

Remember, if the Earthquake is big enough and hits us right, parts I-5 will be destroyed, the airport landing fields will buckle and we will be cut off from food and quite possibly water!

Tell me how we are prepared for anything like Japan just went through.

Dan McShane said...

Ryan: The waves won't be that high in Bellingham. Walsh (2004) is refrenced in the paper by Day you reference.
As I noted, Bellingham and the Port have tsunami information for the water front and presumably they will take this into account in regards to planning. I do not want to assume anything at this point.
As for the earthquake itself or for that matter other quakes, I believe you are correct in that transportation will be highly disrupted for a significant period. I have been very interested in this aspect of the impacts in Japan and how they have been responding to the transportation challenge.

Anonymous said...

If the tsunami is high enough or backed by enough force, it could flow into Lake Whatcom and destroy our water supply!

Are there any plans for back up generators to keep pumping the sewage so it won't spill into the lake also!

Dan McShane said...

Anon: That is just goofy. Besides if the wave was that big we would no longer need a water supply as we would no longer be here.

Anonymous said...

I have wondered for some time now, how a tsunami would affect us here in Birch Bay. We live at about 61' above sea level and I've wondered if we'd be safe from a tsunami. Your article here is the first info I've seen specific to our area ~ in your opinion do you feel we are safe here? Why is there little to no information on this, anywhere?
Stacey

Anonymous said...

I would also like to know how a tsunami would affect the Birch Bay and Blaine area. Thanks.

Anonymous said...

Would the author kindly offer his assessment of how Birch Bay would be affected specifically regarding the Bay Crest neighborhood...Lighthouse Dr. at Seashell. Online checks indicate my residence is 54" above sea level and the assembly point at Blaine Rd. and Bay Rd. is above 100'. I'm unclear if the assembly area is for post-quake/tsunami assembly only or should one evacuate much further away from the assembly location?

Dan McShane said...

The tsunami impact at Birch Bay should be fairly mild and will be dependent on tides. If you are at 54 feet you are way above any possible tsunami hazard.

A Johnson said...

How about Pt Roberts? I want to buy property there and I think finding escape routes into canada are as important as avoiding areas with high waves. The border patrol will not be operational at point bob in the event of a megathrust. Waves in Fukushima were 50 ft. Tsunami in Alaska were 220 ft. Megatsunami are expected to be minimal near the Fraser River delta because Vancouver Island is protective

The 3 gas stations, if they survive the quake will be either non-operational, or become fireballs. Keep your vehicles gassed up!

In Fukushima, the ground water became quickly contaminated after the tsunami... Pt Bob has a long history of water problems. Stored water will become valuable very quickly as utility disruptions in metro vancouver cascade along the grid to bellingham seattle and portland.

at least Pt Bob has lots of firewood if Cascadia breaks in winter.