PUB00047

• Year: 2000
• Title: SECWD/Arkansas Basin Preferred Storage Options Plan Final Draft Report
• Author: GEI Consultants, Inc
• Description: SECWD/Arkansas Basin Preferred Storage Options Plan Final Draft Report
• Publications - Doc Type: Water Resource Studies

Final Draft - Preferred Storage Options Plan
Southeastern Colorado Water Conservancy District
June 8, 2000

4.0 EVALUATION OF ALTERNATIVE STORAGE PLANS

Chapter 3 presents alternative plans for developing storage capacity to meet District-wide water
management objectives through the year 2040. Hydrologic modeling was completed for five of
the plans to evaluate how the storage, both re-operation storage and new reservoir capacity,
could potentially impact stream flows and reservoir levels in comparison to historical operations.
The alternative plans were formulated using the six storage options selected by the District and
SSC following completion of the GEl Study. The six options are: re-operation of the Fry-Ark
Project; enlargement of storage capacities in Turquoise Lake, Pueblo Reservoir, and Lake
Meredith; enlargement of proposed storage at the Williams Creek Reservoir site; and
construction of new storage at various gravel lakes sites.

Alternatives A through E, described in Chapter 3, involve various combinations of the six
storage options. Hydrologic modeling was completed for each of these alternatives, with results
summarized in Section 3.4. After the modeling work was completed, two additional storage
alternatives were identified. These alternatives were not modeled directly; however, their
potential impacts on stream flows in the Arkansas River would be similar to those identified for
Alternatives A through E. This determination is based on the findings that the stream flow
effects, associated with operation of Alternatives A through E, do not vary significantly, despite
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reservoir storage capacity. Many of the impacts identified in the technical and environmental
studies, especially the changes to stream flows of the Arkansas River, are independent of storage
alternatives being considered. Additional water will be imported, up to decreed amounts, to
meet year 2040 demands. This change will affect stream flows and will occur even if no

additional storage is provided. The stream flow impacts associated with the preferred storage
options plan are anticiR<!.ted to be similar to those described for Altematives A through E. Once
the preferred plan is selected by the SSC, and the Enterprise Board, hydrologic modeling will

be prepared for the selected plan.

4.1 Water Supply Performance

The results of hydrologic modeling described in Section 3.4 were evaluated to determine how
the six storage options (re-operation; Turquoise, Pueblo, and Lake Meredith enlargements;
Williams Creek; and gravel lakes) when implemented in various combinations would compare
in terms of their performance as potential water supplies for the District entities. Two major
evaluation factors were considered:

. Operational flexibility (as measured by location, ability to store available inflows,
and ability to deliver to points of demand)

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~ GEl Consultants, Inc.