Siskiyou County Board's opposition to dam
removal Letter to the editor by Marcia H. Armstrong,
Supervisor District 5 (representing the communities downriver of
the dams)
Siskiyou County 5/11/08
The Klamath Basin Restoration Agreement is premised on dam
removal, which poses significant concerns for communities
downriver from the dams. There is an estimated 20 million
cubic yards of sediment stored behind the dams. Siskiyou
County had a consultant do a preliminary analysis of the
sediment studies that had been done. The 2006 Klamath River
Dam and Sediment Study was not comprehensive, nor did it
detail negative impacts. In fact, it listed a large group of
additional studies that would need to be done to develop that
information. The American Rivers study did not use the
accepted and vetted engineering model (HEC-RAS) for sediment
transport, nor did it use available detailed topographic
reservoir profiles. The model they did use accounted for sand
sized sediment, when the majority is silt sized. The study is
questionable. The studies done by the California State Coastal
Conservancy relied on the defective American Rivers study.
They failed to take into account that no study had been done
on how the flows will carry the sediment.
Dam removal would likely raise the river bed and height of the
river. (In the recent decommissioning of Marmot dam with
955,000 cubic yards of stored sediment and erosion of 131,000
cubic yards of sediment, the downstream channel rose 13 feet.)
This could inundate adjacent land downriver where there are
homes and infrastructure. The fine sediment could also be
trapped in gravel spawning beds, requiring a 100 year flood
event to return them to a suitable state for salmon.
A review of sediment bore samples showed some presence of
ethylbenzene and creosote compounds. Three bore samples taken
in each of the reservoirs indicated that the sediment contains
dioxin. Two samples were above human health standards. (You
can read about that toxin and its carcinogenic health impacts
here
http://www.ejnet.org/dioxin/. ) It is likely that the
levels of dioxin could kill the benthic community or bottom
ecology of the river and that a large quantity of floating
organic toxic waste particles would pollute the mouth of the
estuary.
The Klamath dam removal proposal would be the largest in the
United States and evidence is that there may be significant
risks involved. It is evident that the comprehensive
scientific studies needed to assess this option to determine
the impact on human beings and the environment have not been
done. This includes: (1) detailed studies using a well-vetted
model of sediment transport and deposition; (2) evaluation of
the impact of resultant sediment loads on fisheries habitat;
and (3) further evaluation of sediment toxicity. On behalf of
the health and welfare of my downriver communities, I call for
a halt of further action on the agreement until such analysis
has been done.
On another note, rate payers should take note that, according
to PacifiCorp, the cost of retrofitting of the dam to
accommodate fish bypass can be amortized over 30 years and
rate increases spread out over that time. Dam removal,
however, is an immediate expense and will be felt up front by
the ratepayers. Claims that dam removal is the better option
does not pencil out, nor does it withstand scientific
scrutiny.
Marcia H. Armstrong, Supervisor District 5 (representing the
communities downriver of the dams)
Siskiyou County
(530) 468-2824
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