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This Website is Dedicated to Alvin Alexander Cheyne January 10, 1921 - June 17, 2005 |
Brownfield Partners Inc.
475 17th Street, Suite 950
Denver, Colorado 80202
303.893.3989
475 17th Street, Suite 950
Denver, Colorado 80202
303.893.3989
Memorandum
To: Frank
DeMarco – County Counsel, Siskiyou County, CA
From:
Stuart L. Miner – Brownfield Partners, LLC
John Lambie – E-pur, LLC
John Lambie – E-pur, LLC
Re:
Preliminary Review of Klamath River Dam and Sediment Investigation
Overview
Brownfield Partners, LLC (BP) and E-pur, LLC (E-pur) have performed
a preliminary review of documents addressing dam removal and
sediment evaluations on the Lower Klamath River hydropower system
owned and operated by PacifiCorp. Our review on behalf of Siskiyou
County was performed in a very short time frame and included a
limited number of selected
reports taken from a very large body of studies and investigations. For this reason, our review and findings should be considered of a preliminary nature. A list of thirteen documents related to sediments that we were able to obtain and read is attached as Table 1.
reports taken from a very large body of studies and investigations. For this reason, our review and findings should be considered of a preliminary nature. A list of thirteen documents related to sediments that we were able to obtain and read is attached as Table 1.
Summary Recommendation
There
have been numerous studies of Klamath River hydropower dams
performed since 2001 for a number of different “clients” and with
different goals and purposes. These studies include, for example:
1.
Studies completed by PacifiCorp on dam retention for relicensure by
the Federal Energy Regulatory Commission (FERC);
2. Studies done by FERC on alternative energy generation alternatives; and
3. Studies done by intervenors to the FERC relicensing process that have looked at dam removal.
2. Studies done by FERC on alternative energy generation alternatives; and
3. Studies done by intervenors to the FERC relicensing process that have looked at dam removal.
Based on
the studies reviewed by BP and E-pur, no entity has completed an
independent analysis of alternatives for the dam and hydropower
generation that objectively looks at the risks and cost/benefit
ratio of a realistic range of possible alternatives from dam removal
to alternate hydropower generation alternatives. The 2006 Klamath
River Dam and Sediment Study, itself states:
· “It
(2006 Study) makes no attempt to provide a comprehensive or final
analysis of dam removal as a project management alternative.”
· “Nor
does this report attempt to characterize in detail any adverse
affects associated with the dam removal scenario presented.”
The 2006 Study also presents in Appendix J a comprehensive list of “Additional studies and analyses that would be necessary precursors to dam removal.”
Therefore, BP and E-pur strongly recommend that such
a multi-disciplinary study that evaluates the economics and
predictable engineered outcomes to modifications to the hydropower
system be undertaken by Siskiyou County or by a group of potential
settling parties to the FERC relicensing. Assistance to fund such a
study could be sought from a state agency such as the California
Resources Agency.
Review of Existing Sediment Studies for Klamath
River Dam System and Concepts of Dam Removal
PacifiCorp performed an evaluation of the quantity
and the likely sedimentary textures (e.g. grain-size and wood
content) of the sediments (JC Headwaters 2003). They estimated that
there is roughly 14.5 million cubic yards of sediment behind the 4
dams under discussion for removal (Boyle, Copco 1, Copco 2, and
IronGate Dam). Most of this sediment is in the silt size-fraction.
American Rivers, a public interest group, completed a
rudimentary evaluation of potential sediment transport after dam
removal using Stillwater Sciences in 2004. This study did not use an
accepted and well vetted engineering model for sediment transport
(1). Stillwater had data from PacifiCorp’s 2003 work but failed to
take advantage of the detailed topographic profiles of sediment in
the reservoir to perform a sediment transport analysis. Further they
used a model that they coded the software for that accounts for only
sand sized sediment deposition and re-transport; the majority of
sediment in the Klamath River reservoirs is silt sized or finer
according to the 2003 and subsequent 2006 data. The depositional
behavior and re-transport of those grain size fractions intermixed
with sand and some gravel has not been evaluated. Stillwater
Sciences has not done a useable analysis of the expected sediment
depositional behavior of the Klamath River without the lower four
dams. The river bed within and below the dam areas will
re-equilibrate to the old hydraulic character of the Klamath River
but the time scale for this and consequences for this have not been
appropriately evaluated.
Potential consequences of downstream sediment
deposition include:
§ Raising the bed height of the river several feet;
§ Entrapping fine grained sediment within the gravel beds below the dams such that it will take large floods (i.e. 100-year return frequency) events to hydraulically rework them to a native state suitable for benthic habitat conducive to healthy salmonid fisheries in these reaches;
§ Deposition of polluted sediment into the riverbed and overbank sediment deposits depending on the timing and form of reservoir drawdown; and
§ Polluting the mouth of the estuary with a large quantity of neutrally buoyant organic waste particles which contain the majority of toxins in the reservoirs.
§ Entrapping fine grained sediment within the gravel beds below the dams such that it will take large floods (i.e. 100-year return frequency) events to hydraulically rework them to a native state suitable for benthic habitat conducive to healthy salmonid fisheries in these reaches;
§ Deposition of polluted sediment into the riverbed and overbank sediment deposits depending on the timing and form of reservoir drawdown; and
§ Polluting the mouth of the estuary with a large quantity of neutrally buoyant organic waste particles which contain the majority of toxins in the reservoirs.
The California State Coastal Conservancy (the
Conservancy) has funded a number of studies and evaluations since
2006. A re-estimate of the quantity of sediment behind the dams was
made by Dennis Gathard, PE in 2006 using the PacifiCorp data from
2003; Gathard estimates that roughly 20 million cubic yards of
sediment is resident in the reservoirs behind the three dams
mentioned with Copco 2 being devoid of sediment. Gathard Engineering
then evaluated how a channel would cut through and carry sediment
out of the reservoir stockpile; however he relied upon estimates of
sediment concentration that are based upon the limited analysis
performed by Stillwater Sciences; no study has been done that
evaluates the “competency” of stream flow in a dynamic model to
carry sediment and re-transport it.
An evaluation of sediment depth, grain-size, and some
sediment quality characteristics on three of the reservoirs, JC
Boyle, Copco 1 Reservoir, and Iron Gate Reservoir, was performed by
Shannon & Wilson in 2006 (GEC 2006 Appendix D). Five locations in
the JC Boyle Reservoir, twelve locations in the Copco 1 Reservoir,
and nine locations in Iron Gate Reservoir were sampled for sediment
depth and quality. Sediment quality was generally benign with
respect to metals, PCBs, or herbicides pesticides. One detection of
ethylbenzene was reported in the few samples analyzed for volatile
organic chemicals (VOCs). Six samples showed evidence of creosote
compounds (i.e. naphthalene and phenanthrene as examples of PAHs in
creosote) at low concentrations. One notable concern is that one
sediment sample for each of the three reservoirs was analyzed for
dioxins and it was found in all three samples in the range of 2.5 to
4.8 picograms per gram or parts per trillion (ppt) TEQ as
2,3,7,8-TCDD. The Canadian advisory for salmonid habitat is 1 ppt
2,3,7,8-TCDD. The Oregon residential soil screening level for human
heath is 3.6 ppt 2,3,7,8-TCDD and the California residential soil
screening level for human heath is 4.6 ppt. One or two of the
samples exceed those standards for dioxins depending upon which
states screening level you compare. The sediment tested is in
California. Dioxins are known human carcinogens and they are
bioaccumulative within the food chain. Dioxin is a known constituent
in pentachlorophenol and there are known pentachlorophenol usage and
spill sites on the Upper Klamath River Lake. More analysis of the
potential for impact from release of these sediments in the
reservoirs for dioxin quality is warranted.
Summary Points on Sediments
§ Studies are preliminary and unreliable on outcomes
of sediment transport after dam removal
§ Potential short-term and long-term salmonid habitat disruption cannot be estimated as a result of the lack of studies
§ Sediments appear to be generally benign but more testing for ubiquitous cancer causing chemicals such as dioxin are necessary
§ Potential short-term and long-term salmonid habitat disruption cannot be estimated as a result of the lack of studies
§ Sediments appear to be generally benign but more testing for ubiquitous cancer causing chemicals such as dioxin are necessary
Detailed Recommendations
It is recommended that Siskiyou County should:
1. Request that detailed studies of sediment
transport and redeposition be done using well vetted public-domain
sediment models such as HEC-RAS from the Army Corps of Engineers;
2. Request that an evaluation of the probable sediment loads be compared to aquatic habitat requirements to estimate the impact to the fisheries habit that is to be restored by these proposed actions;
3. Require that further evaluation be done of sediment toxicity for dioxin and related compounds;
4. Require the broad stakeholder group to complete an engineering evaluation/cost analysis or engineering feasibility study in advance of any decision on dam relicensing, removal. A more comprehensive evaluation would look at:
a. Habitat impacts for each alternative,
b. Economic impacts to County government from each alternative,
c. Economic impacts to County resident groups from each alternative,
d. Probable water quality impacts,
e. Potential human health risks, and
f. Other potential impacts (e.g. construction issues)
5. Organize the stakeholder group to obtain grant funding or other funding source for the necessary studies.
2. Request that an evaluation of the probable sediment loads be compared to aquatic habitat requirements to estimate the impact to the fisheries habit that is to be restored by these proposed actions;
3. Require that further evaluation be done of sediment toxicity for dioxin and related compounds;
4. Require the broad stakeholder group to complete an engineering evaluation/cost analysis or engineering feasibility study in advance of any decision on dam relicensing, removal. A more comprehensive evaluation would look at:
a. Habitat impacts for each alternative,
b. Economic impacts to County government from each alternative,
c. Economic impacts to County resident groups from each alternative,
d. Probable water quality impacts,
e. Potential human health risks, and
f. Other potential impacts (e.g. construction issues)
5. Organize the stakeholder group to obtain grant funding or other funding source for the necessary studies.
Closing
We are pleased to provide this preliminary review and
analysis for Siskiyou County. As noted in the Introduction, our
analysis and conclusions are based on a very short-term review of a
limited number of studies. We believe the conclusions made are
supportable and accurate. However, we strongly recommend that
Siskiyou County pursue a more comprehensive analysis
of this issue, as noted above.
of this issue, as noted above.
Please let us know if you would like our further
assistance in evaluating matters on the Klamath River system.
__________________________________________
(1) The model used, DREAM-1, was designed by Stillwater Sciences to simulate deposition of coarse sediment like sand.
Attachments: Table 1 Documents Identified and Reviewed by
Brownfield Partners and E-pur
