Subject: Chehalis Wildlife Area/Gravel Pit remediation
Date: Sep 22 19:38:02 1999
From: John Chapman - ragweed at igc.org


Andy Stepniewski reported:

>OCEAN SHORES SHORE BIRDING AND WESTPORT PELAGIC TRIP11-12 SEPTEMBER 1999

>CHEHALIS WILDLIFE AREA. On the way to the coast, I stopped at the Chehalis
Wildlife Area to look for Green Heron. I was in luck this time (my fourth
try); I had stellar views of an adult perched in the shady recesses of a
dense willow. I reflected on the potential value of abandoned gravel
borrows, particularly if mining is designed so as to retain shallow slopes
at or near water table elevation such as this site apparently has. Presto!
A wonderful marsh habitat can easily develop. There could be hundreds of
wetlands such as this scattered throughout Washington, so pervasive are
gravel borrows. Unfortunately, many have been mined with volume of product
as the primary mission and left with steep sides, significantly reducing
wildlife potential.<

The magazine Washington Geology ran an extensive article in the past
year about the ecological implications of flood-plane gravel mining in
Washington, which might be of interest to folks.

The primary focus of the article was the impact on salmon habitat,
especially from either in-stream gravel mining or from gravel pits
sited close to rivers (During a flood, the river can shift channels and
end up with a significant portion of the channel running through a gravel
pit, the result being less than ideal habitat for young salmon.)

However, it did talk about remediation of former gravel pits into
meaningful habitat by creating shallow slopes, variable shoreline
and "planting" woody debris. Good for young salmon, and birds
too.

I'm sorry I don't have the exact reference - I don't think I saved the
article. However, Washington Geology is published by the Washington State
Geology and Earth Sciences Division in Olympia, and is distributed free
to anyone who wishes to subscribe. It has some interesting articles,
though much of it is oriented toward the mining industry.

John Chapman
Seattle, WA
e-mail to: ragweed at igc.org