Saturday, September 12, 2009

Weaverling Spit

This little point in southern Fidalgo Bay is a little hard to decipher, but I suspect it is basically a rocky island separated from the rest of Fidalgo Island by a tombolo. The tombolo, which probably once harbored tidal wetlands and a native community, is now covered in fill and RVs and an old railroad grade (which is now a bike trail). There are small pocket beaches on the north side (not really pockets, since drift can get past at low tide) of the rocky point and a small spit at the eastern end (aerial photo - courtesy Google).

The railroad used Weaverling to launch it's trestle across the bay and the resulting causeway has altered the southern shore of the point. The causeway and trestle has probably had several effects. It must have altered tidal circulation at the south end of the bay and may have reduced the exposure of the southern end of the bay from the rare northerly storms. It protects the little spit at the tip of the point from southerly wave action - there was never much due to the limited fetch, but now there's none. This might be expected to lead to small shifts in the configuration of the feature over many decades - but since change would be driven by those rare northerlies, it might take many decades for much change to occur.
The causeway has also created a long skinny, rock-lined lagoon on the south side of the point.

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