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Metadata for Court Order Spill Web-page:
In accordance with the Court
Order, spill was initiated at the Snake River Projects at 0001 hours on
April 3, 2009. The Court Order calls for the following spill levels at
the Federal Snake River Projects:
| Project |
Spring
Spill (April 3 - June 20) |
Summer
Spill (June 21 - August 31) |
| Day / Night
Spill |
Day / Night
Spill |
| Lower Granite |
20 Kcfs /
20 Kcfs |
18 Kcfs /
18 Kcfs |
| Little Goose |
30% / 30% |
30% / 30% |
| Lower Monumental |
Gas Cap /
Gas Cap |
17 Kcfs /
17 Kcfs |
| Ice Harbor |
30% / 30%
vs 45 Kcfs / Gas Cap |
30% / 30%
vs. 45 Kcfs / Gas Cap |
In accordance with the Court
Order, spill was initiated at the Lower Columbia projects at 0001 hours on
April 10, 2009. The Court Order calls for the following spill levels at
the Federal Lower Columbia River Projects:
| Project |
Spring
Spill (April 10- June 30)
| Summer
Spill (July 1 - August 31) |
| Day / Night
Spill |
Day / Night
Spill |
| McNary |
40% / 40% |
50% / 50%
(beginning June 20, 2009) |
| John Day |
30% / 30% vs. 40% / 40% study |
30% / 30% vs. 40% / 40% study |
| The Dalles |
40% / 40% |
40% / 40% |
| Bonneville |
100 Kcfs /
100 Kcfs |
85 Kcfs / Gas Cap (June 21 - July 21)
75 Kcfs / Gas Cap (July 21 - August 31)
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Court Order Spill:
All projects have a minimum
powerhouse flow requirement:
| Project |
Minimum Powerhouse
Flow (kcfs) |
| Lower Granite |
12 |
| Little Goose |
11.5 |
| Lower Monumental |
11.5 |
| Ice Harbor |
9.5 (Mar-Jul), 9 (Aug-Nov) |
| McNary |
50 |
| John Day |
50 |
| The Dalles |
50 |
| Bonneville |
30 |
At low flows the Court Ordered
spill amounts cannot always be provided along with minimum powerhouse
flows (PH Min). In this instance all estimates of Court Order Spill (i.e.,
red line on graphs) are adjusted for project specific powerhouse minimum
requirements using the following criteria:
If Total Flow > Court
Order + PH Min ' Court Order = Court Order
If Total Flow < Court Order + PH Min ' Court Order = Total Flow
- PH Min.
12-hr Avg TDG:
The 12-hr average TDG levels that
are presented in the graphs above are according to the Oregon method of calculation.
This method of caluclation estimates the 12-hr average TDG based on the 12 highest
hourly TDG readings in a 24 hour period. These 12 highest hours are not necessarily
consecutive.
Spill to the Gas Cap:
In the Court Order, spill to
the gas cap means to spill a volume of water that achieves the total dissolved
gas (TDG) waivers, specifically, the 120% tailrace TDG criteria, and the
downstream forebay 115% TDG criteria. To assess whether the Court Order
is being implemented the spill should be evaluated relative to whether
the 120% TDG is being met in the tailrace, and the 115% is being achieved
at the next downstream forebay. Both TDG levels are plotted on the graph
for each project.
The US Army Corps of Engineers
(COE) develops daily levels of maximum spill that the COE estimates will
not exceed the TDG criteria. The "spill caps" estimated by the
COE are given to the project operators as maximum spill levels. The "spill
caps" presented in the graphs are taken directly from the COE. These
"spill caps" are updated by the COE every two weeks so the graphs
may lag several days. The COE's assessment of meeting the Court Order
is dependent on whether a project spills to the "spill caps".
IHR:
IHR is conducting spill tests under two different levels of Court Order
Spill (30%/30% versus 45 kcfs/Gas Cap). This test will begin on April 28th and is
expected to run through mid-July. These different spill levels will be tested in 2 day blocks.
MCN:
MCN will no longer be testing differnt spill levels in summer 2009.
Instead, beginning June 20th, MCN will spill a constant 50% of instantaneous flow through the entire
summer season.
JDA:
JDA will be testing two levels of Court Order spill in 2009, beginning April 27th
(30%/30% versus 40%/40%). This test was expected to run through the spring and summer. However,
the TSW at JDA was shut down in early June and the test was put on hold until further notice. Until
then, spill at JDA is expected to remain at 30% of instantaneous flows.
Note: Spill at some
projects varies relative to flow, therefore the scale of Y-axes may be
different for each project and may change from week to week at an individual
project.
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