Lower South Platte River Study

• Contractor Name: Colorado Water Conservation Board
• Loan Projects - Doc Type: Feasibility Study

Lower South Platte River Study
Colorado Water Conservation Board
' December 2001
Additional analyses were performed for the North Sterling, Harmony, and Peterson systems
' (with Winter Diversions) to develop graphical relationships between storage volume, target
releases, and reliability. Results are shown on Figures 2.2 through 2.4, which indicate the
following:
' • Significantly more storage is needed to develop a reliable water supply using the
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North Sterling system in comparison to the Harmony system or the Peterson system.
' For example, 10,000 acre-feet of storage could meet a target release of 3,000 acre-feet
per year with 90 percent reliability(see Figure 2.2). The same target release and
' reliability could be achieved from the Harmony system with a reservoir of 3,600 acre-
feet (see Figure 2.3).
• A decrease in the reliability of meeting a target release amount enables a higher target
release. For example, a 10,000 acre-foot reservoir supplied by the Harmony system
could meet a target release of 1,400 acre-feet with 100 percent reliability(i.e., no
' shortages in the period of record) or a target release of 6,000 acre-feet with 90 percent
reliability(i.e., shortages in 10 percent of the months when releases are made).
• The Peterson system can provide the greatest target releases for given storage
volumes. However, as shown later in the report,the Peterson system cannot be used
' to provide water to many of the more-attractive storage sites.
As discussed in Section 5.1, water developed through additional storage in the Lower Basin
' could be released for a variety of beneficial uses.
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GEI Consultants, Inc. 2-15 01002 Dec 2001 Lower South Platte River Study
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