Sunday, April 28, 2013

Indian Island

Most of Indian Island is managed by the Navy as a convenient place to store WMD, but the bluff and the beaches south of the county road are public, accessible, and wonderful. Two weeks ago we brought the Beach Watchers class here -- on a beautiful afternoon after they had been cooped up in a small room watching slides all morning.

This one mile stretch includes the tombolo between Marrowstone and Indian Islands, a long stretch of till bluffs, and a beautiful spit that encircles a tidal lagoon.  There are several different places you can park and get to the beach.


Net drift is northwest into Oak Bay, where sand and gravel once accumulated to form another long tombolo between Indian Island the the mainland.  This was altered when they made the cut back in the early 1900s and the beaches have been sort of on their own ever since, although the east side (this one) and the west side have taken different paths.

We saw some fairly fresh failures in the glacial till bluffs, evidence of an oblique bar building at the base of the gravel beach, and some relatively recent overwash on the spit (recent means the last 6-7 years - February 2006 and December 2012 both had events that probably carried gravel over the berm, but there may have been others, too).

Previous Posts:
Indian Island  (January 2007)
Marrowstone Isthmus (October 2010)
Indian Island, Eastern shore (April 2012 - posted in October)

Port Townsend

This beach lies at the edge of the shipyard at the west end of Boat Haven marina.  It's the jumping off place for the Larry Scott trial, which follows the old railroad grade along the bluffs and past the paper mill, before heading up the hill to the west.

This stretch of shoreline was once a barrier beach, separating Kah Tai Lagoon from Port Townsend Bay. Now it's the main road into town, a large marina and boat yard, and a lot of commercial real estate.  There used to be a curved railroad trestle extending offshore to a barge dock, but the last portions were removed a few years ago and the small riprapped headland in these shots was where the trestle began.


The beach was once continuous along the northern shore of the bay, with longshore transport generally to the north and east.  Sediment derived from bluffs in the vicinity of Old Fort Townsend would have passed here on its way towards Point Hudson and eventually to Point Wilson.  In some communities, historical development completely obliterated the foreshore, but here in Port Townsend the old wharves and and made land simply broke the shoreline into a complex series of pocket beaches.  They are still neat beaches - and wonderful opportunities - they're just not part of a larger system the way they once were.

What caught my eye was the contrast between the two adjacent beaches.  The longer sandier beach on the east and the small, coarse gravel beach tucked up against the promontory.  Is there some process keeping these beaches segregated and different - perhaps different responses to waves from differing directions? Or is this a historical artifact, just waiting for time to blend these beaches into a single curve?  Maybe the beach is still responding to the change in wave regime that accompanied the removal of the old rail trestle.