Summary Report ‎(Working Draft)‎ Modeling of Reservoir Management Strategies for Lakes Powell and Mead December 2005

• Description: Summary Report ‎(Working Draft)‎ Modeling of Reservoir Management Strategies for Lakes Powell and Mead December 2005
• State: CO
• Title: Summary Report ‎(Working Draft)‎ Modeling of Reservoir Management Strategies for Lakes Powell and Mead December 2005
• Water Supply Pro - Doc Type: Meeting

Modeling Results for
Colorado River Basin States' Modeling of
Colorado River and Reservoir Management Strategies
4.0 Sensitivity Analysis of Step
Shortage & Hybrid Alternatives
4.1 Hybrid
As discussed in Section 2, revisions were made to the Hybrid concept resulting in
a total of four Hybrid strategies. The goal of these revisions was to test the
sensitivity of two key parameters: the elevation at Mead at which Powell begins
to make balancing releases (Mead balancing elevation) and the elevation range
over which Powell would release a minimum of 7.48 MAF (7.48 band). All other
parameters were kept constant. For all Hybrid revisions the shortage strategy was
Step Shortage Original.
4.1.1 Powell & Mead 10th Elevation Percentiles
3,660
3,640
_ 3,620
0
3,600
W
3,580
3,560
3,540
3,520
2005
Figure 4 -1
Lake Powell 10 "' Percentile Elevations
—0—Normal
—6— Hybrid
—* Hybrid rev1
* Hybrid rev2
-+F Hybrid rev3
2010 2015 2020 2025
Calendar Year
Figure 4 -1 shows that both Hybrid rev2 and Hybrid rev3 are consistently above
the Hybrid Original 10th percentile with the exception of one year. The reason for
this is that both of these revisions contain an elevation range of 50 ft under which
Powell releases 7.48 MAF, a 25 ft increase compared to the Hybrid original. Even
with the increased Mead balancing elevation, Hybrid rev3 is still higher than
Hybrid Original due to the increased 7.48 band.
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