A bulk of the material appears to be shifted eastward, a predictable consequence of the westerly swell. Which is fascinating all by itself. The waves wrap around the delta from the west, breaking along the shore at incredibly high angles, with big implications for both sediment and surfers.
AERIAL VIEW
Wood has also been flushed out of the reservoirs. Wood of all sizes from small chunks of bark to large branches has been piled into broad debris fields at the river mouth, stacked in ridges by successive high tides, and then more recently eroded or washed away, spreading out in a thin band along the beach to the east.
Wood has also been flushed out of the reservoirs. Wood of all sizes from small chunks of bark to large branches has been piled into broad debris fields at the river mouth, stacked in ridges by successive high tides, and then more recently eroded or washed away, spreading out in a thin band along the beach to the east.
The new sand has had
little noticeable effect on the ongoing erosion of the gravel berms on the east
side of the delta, which have been retreating rapidly for decades. Maybe the new sediment will begin to slow
this process, but will it do it by accreting new sand and gravel directly to
the beach face, by dissipating wave energy on the broad sandy bars, or will the
current beach face simply be abandoned as a new series of spits and lagoons
forms farther offshore?
The removal of the dams is
unleashing a complex chain of events, much as the construction of the dams did
a century earlier. Some things will change rapidly – particularly those things that
are moved readily by frequent processes, like sand moving through the lower river. Some things will take much longer,
particularly those that involve difficult to move material moved by infrequent
processes – like new cobble berms forming on the delta.
The Elwha isn't just about
emptying the reservoir and watching the exposed soils revegetate. It isn't just about restoring a natural grade to a river that had been ponded behind two large dams. The removal of the dams restores an incredibly complex
system that extends far beyond the reservoirs. Fish that spend most of their
time in the open ocean will now be able to swim up into Olympic National Park,
for the first time in a century, to lay their eggs in the upper watershed and give rise to new
generations of Elwha River salmon. Sand
and gravel that has been trapped in reservoirs will now move downstream,
rebuilding the delta and influencing the beaches all the way to Ediz Hook in
Port Angeles.
I’m just an excited spectator
out at the Elwha. There are many folks
much more actively involved and much more knowledgeable about the river and its
beaches. Here are a few of them.
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