Driftwood Dynamics


Driftwood is one of the aesthetic elements we enjoy at the beach.  We like to look at it, collect it and make things with it.  Although not recommended, it fuels a great fire at a picnic.  Even its name has a pleasant ring, the word "drift" implying carefree leisure.

Did you ever wonder how it got there?  It turns out this is not well known and is now a subject of study at Evergreen State College.  I do have some insight into the process locally.  It is basically created by the weather.  Recall the torrential rains we had about two weeks ago swelling rivers out of their banks.  When the Skagit River floods, wood debris and even entire trees are dumped into southern Skagit Bay.  The journey may have begun several miles upriver.  The currents are now bringing this material into the upper bay, a journey of between 8 and 15 miles (15-25 km).  This is a recurring pattern after every Skagit flood event.  The photo above shows some of this debris moving in with the high tide this morning.


An outgoing tide together with a light breeze from the southwest organizes the debris into a visible tideline.


More material continues to accumulate at the shoreline, probably pushed there by the light winds.


When the tide recedes, a brand new collection of driftwood is left on the beach.  It will continue to sort itself and move with the tides and the winds until it finds a resting place for the season.  The bark will be knocked off and the bare wood will bleach in the sun.  Very large pieces might stay put for several years, but in general, this is a continuous process of redistribution.  Eventually it might find a permanent resting place in a spot where the tides and currents are relatively static.  One such spot is the far north end of Similk Bay off to the left of the photos.

Driftwood becomes an important part of the ecosystem.  It helps accumulate and stabilize beach sands, provides hiding and nesting sites for wildlife and feeds biological materials into the waters.  It harbors food for marine life and dune grasses will grow around it.  It becomes part of the structure of the beach and moving it can cause erosion.  It also helps protect property owners from wave action and storm surges.  Collect it thoughtfully and never disturb driftwood in protected sanctuaries.  Without driftwood, the beach would be incomplete and our world would be less beautiful.

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