Tuesday, February 14, 2017

Nourishment in Washington State - A look at Ediz Hook

Looking west along Ediz Hook at nourish material place in January along the base of Ediz Hook.  Photo shot from a location immediately east of the paper mill at the base of the Hook (red circle in map below).
Shoreline nourishment, where sand and/or gravel is placed on the shoreline to change the profile or character of the beach, is a relatively infrequently used tool in Washington State, at least compared to other parts of the country.  In Western Carolina University's beach nourishment database, for example, Washington State ranks 4th to last in spending on shoreline nourishment, behind Maine, New Hampshire and Rhode Island.

Part of US Army Corps plans for nourishment on Ediz Hook that took place in January 2017.  This particular nourishment project was limited to the areas in the black box at the base of Ediz Hook.
Ediz Hook though, again based on WCU's nourishment database, is the most nourished shoreline in Washington's protected waters (i.e. in Puget Sound and the Strait of Juan de Fuca).  On Ediz Hook nourishment is primarily used, interestingly enough, to protect the large rip rap material that stabilizes Ediz Hook, and is placed every few years.  Just last month there was a placement of roughly (by my math based on the drawing above) 35,000 cy of sand and cobble to replenish the eroding beach at the base of the rip-rap on the west end of Ediz Hook.

Looking east from the location marked with a red dot in the map above.
 The last nourishment on Ediz Hook that I am aware of occurred at some point in late 2011.  I snapped this photo in January of 2012 from more or less the same location and perspective as the top photo in this post:

Ediz Hook, though, is nothing if not exceptional in its ability to erode material off of its steep shoreface, end even by early April (the photo below was shot on 8 April 2012) most of that material has been eroded off of the upper beach:

Pretty impressive. But certainly it did act to fortify the toe of that beach, as shown in this beach profile from that area that I post a few months ago:

The first profile above is from March 2012.  Of course over the subsequent years that section of beach has eroded chronically.