Wednesday, March 25, 2009


What better location for a Canadian-U.S. workshop on sea level rise than a large resort built on the tip of a spit within a stone's throw of the international border and within a meter of high water.

Semiahmoo Spit is located at the distal end of a drift cell that begins
about 5 miles south near Birch Point. For thousands of years, sand and gravel has traveled north, traversing the mouth of Drayton Harbor on this slender strip of land, and then disappeared under the bar. Seriously, the beach just sort of runs under Packers Lounge, then shows up on the other side as the slightly mellower beaches of Tongue Point (next post) at the tip of the spit. Packer's would be an appropriate location for some future meeting of coastal geomorphologists - the bar at the end of the beach.

The distal portion of Semiahmoo is large, particularly when compared to the narrow neck of the spit that you have to cross to get to it (see the aerial - click on the title of the post). Most of this land was built up with fill (dredged from the channel and the marina, I assume), so it has a couple foot headstart on anthropocene sea levels -- though it will become increasingly hard to get here, or to get away from here, during the big storms that will toss gravel and logs over the access road. Fortunately, most of the development on the spit has been kept away from the shoreline and except for the riprap that protects the neck, the beach is in good shape - except that in some places it is backed by an unnatural eroding bank of fill.

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