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Summary of amendments and comparison to BiOp
The mainstem plan will consider ways in which the hydrosystem
operations, called for in the biological opinions, could be adjusted so
that they meet not only the needs of ESA-listed stocks, but the
requirements of the Northwest Power Act, which has a broader
mandate. The plan proposes specific revisions focused on benefiting
additional species and additional power system flexibility.
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Areas
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Actions
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Compared to the BiOp
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| Objectives for the Mainstem |
The draft mainstem plan
includes a set of cost effective measures intended to protect,
mitigate, and enhance all the fish and wildlife of the
Columbia River Basin that have been affected by the
development, operation, and management of the hydrosystem. |
May require federal agency
flexibility or changes in the implementation of the biological
opinions. |
| Water Management |
Systemwide water management,
including flow augmentation from storage reservoirs, should
balance the needs of anadromous species with those of resident
fish species, and the needs of migrating fish with those of
spawning and rearing fish.
(Language noted in draft amendments not to imply the
Council is advocating dam breaching on the lower Snake
River. The Council supports the 2000 BiOp's 3, 5 and 8
year reviews of listed fish recovery efforts, to include
offsite ESA mitigation efforts upstream of the lower Snake
River dams.) |
Does not support the spring
and summer flow targets in the NOAA Fisheries 2000 Biological
Opinion due to lack of evidence that they are related to
survival within the range of the agency's control, given
reservoir and other hydrosystem constraints. Proposes a
rigorous evaluation of the BiOp flow targets. |
| Spill |
Proposes an immediate and
comprehensive evaluation to determine the optimum spill level
for each project to increase survival (or at least not
decrease it) while achieving greater efficiencies that would
save energy and money. A rigorous evaluation of the
costs and effectiveness of spillway passage at each dam should
be conducted to determine when and how much to spill. |
Does not propose a change in
current spill operations. |
| Fish Passage |
Calls for an aggressive look
at the removable spillway weirs as another way to spill and
generate power more efficiently. Supports ongoing tests
by the Corps of Engineers of surface bypass systems at the
dams to aid juvenile fish passage, and also ongoing efforts to
improve fish passage at the dams by relocating bypass
outfalls, modifying turbines, and researching fish diseases at
fish passage facilities. |
Does not differ from BiOp. |
| River Operations and Flow
Augmentation |
Spring River
Operations: Highest priority would be to refill upriver
storage reservoirs by the end of June; calls for a 95 percent
probability of refill. Eliminates the BiOp requirement
of April 10 flood control elevation, allowing deeper draft of
reservoirs in winter. More water would be available in
the winter months for power generation and the corresponding
drop in reservoirs would be filled by runoff. This would
have the effect of reducing spring flows by about 10 percent
in most years.
Summer River Operations: In general, would stretch
out the BiOp flow augmentation volume releases from May
through September. Would also reduce the total amount
released from Hungry Horse and Libby (except in lower 20
percent of water years) and Grand Coulee (in all years).
Would cause water to be released at a slower, steadier rate
through the summer, more like a natural hydrograph, providing
benefits for resident fish in upriver storage reservoirs and
in areas immediately below the dams without adversely
affecting salmon and steelhead populations in the lower
regions of the basin. Would reduce flows in the lower
river in July and August, in the 10 percent or so range in
August; would increase flows in September. |
Calls for elimination of the
BiOp target of reservoir refill to within one-half foot of the
upper flood control rule curve by April 10.
BiOp volumes are greater at Hungry Horse, Libby, and Grand
Coulee. The draft mainstem plan spreads the release of
the volume out at all four projects (including Dworshak), and
reduces the total amount of flow augmentation. |
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