September 3, 2010 - Elwha dam removal; Northwest Passage

Friday, September 3, 2010

Hydroelectricity: I'm continuing to follow the removal of two dams on the Elwha River in Washington.

Here is a map I created showing the two dam sites.

Here is the Bureau of Reclamation's information on sedimentation behind the Elwha River dams: nearly 18 million cubic yards of sediment behind Glines Canyon Dam and Elwha Dam.  The Bureau gives this history:

Private companies constructed two large dams on the Elwha River during the early 1900’s. Elwha Dam, constructed during the period 1910-13, is a 105-foot high concrete gravity dam that forms Lake Aldwell 8 miles upstream from the river's mouth. Glines Canyon Dam, built in 1927, is a 210-foot high concrete arch dam that forms Lake Mills 13 miles upstream from the river's mouth. When the dams were first built, they were significant producers of electricity on the Olympic Peninsula. Today, the dams are operated in a run-of-the river mode and generate about 40 percent of the electricity needs for the Diashowa America paper mill in Port Angeles, Washington.
The Bureau also has interesting information on erosion after drawdown.  As we've seen before, drawdown can be done to minimize harms but can also cause serious problems if the newly exposed slopes of the impoundment or riverbank are unstable.

Meanwhile, in Maine, a graphic example of how business climate can make a difference: an entire lumber mill, closed for the past four years, is up for sale and might be moved piece by piece to Siberia.  People often talk about how jobs move overseas; here, not only the (already lost) jobs but the workplace may move.
The situation on the Sebasticook River continues to brew after the Fort Halifax dam removal; now, town officials are considering a renewed investigation into erosion of the riverbanks after drawdown and dam breach.

An interesting bit of fisheries news: Native Americans from the Passamaquoddy Tribe continue to fish federal waters, despite being cited for lack of permits and certain mandatory safety gear during a scallop fishing trip off Nantucket.  The natives point to their indigenous fishing rights.

Arctic news: I have a special interest in the Canadian Arctic, including the fabled Northwest Passage.  Today comes news that a fuel tanker has run aground along that shipping route on a sandbar near Gjoa Haven.

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