Conjunctive Use Model S-1

• Description: Conjunctive Use Model S-1
• State: CO
• Title: Conjunctive Use Model S-1
• Water Supply Pro - Doc Type: Report/Study

Draft — January 27 -5, 2005 Ne4 for- Cir- oulatio
Conjunctive Use Model S -1
The Basin States Technical Team has requested that Reclamation develop a conjunctive
use model in CRSS/Riverware' based on discussions at the meeting held in Phoenix on
January 21, 2005. The model will allow annual releases to be reduced below the
objective minimum release of 8.23 maf from Lake Powell under certain circumstances,
and will also impose a transitory equalization level (at a level below 602(a) storage) at
Lake Powell under certain circumstances as well. This model will be called S -1. The
model will build off the work Reclamation has put into the H -1 model whiehmodel,
which followed the logic used by the Central Arizona Project (Henning et al) in their
Interim Lake Powell Release Trigger spreadsheet model.
The S -1 model has not yet been developed. Contained in this document is a description
of the algorithms and logic to be used in the model.
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The S -1 model will include four adjustable parameters.
• Lake Powell Trigger (LPT) Elevation
Elevation trigger for reducing annual releases from Lake Powell
• Reduced Objective Minimum (ROM) Release from Lake Powell
Annual release volume from Lake Powell when Lake Powell is below the
LPT Elevation and Lake Mead is above the Water Supply Trigger (WST)
elevation
• Water Supply Trigger (WST) Elevation at Lake Mead
Elevation trigger for abandoning the ROM release and returning to the
objective to release a minimum of 8.23 maf from Lake Powell
• Transitory Equalization Level at Lake Powell (TEL)
Temporary equalization level at Lake Powell, a level that is below 602(a)
Storage
The rules in RiverWare in S -1 will allow these parameters to be adjusted to accommodate
investigation of the impacts on the Colorado River System under various combinations of
values for these four parameters.
faftroxi 8.6 MAa
unless we receive direction to use a different
elevation from state representatives.
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There was discussion at the January 21 meeting as to what should be used for the reduced
objective minimum (ROM) release from Lake Powell. There were suggestions of 7.48
maf and 6.5 maf. "' `` 1. 4 ..
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