9604

• UCREFRP Catalog Number: 9604
• Author: Montgomery Watson.
• Title: Yampa River Basin Small Reservoir Study - Final.
• USFW Year: 2000.
• USFW - Doc Type: Steamboat Springs, CO.
• Copyright Material: NO

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

Fe/mwy 2000 CR WCD .. Yampa Riu?r Basin Small Re5eIWi:r Study .. Paf!! . 14

3.0 IDENTIFICATION AND SCREENING OF POTENTIAL SMALL
RESERVOIR SITES

Numerous studies. of the Yampa River basin have identified and evaluated potential sites for new
water storage opportunities. However, the previous studies have generally focused on larger storage
projects (greater than 10,000 ac-ft), which were located on the mainstem Yampa River or on the larger
tributaries. Hydrosphere (1993) identified 64 reservoir sites that were ultimately narrowed down to
eight sites that appeared capable of supporting a storage facility greater than 10,000 ac-ft. The scope
of this investigation focused on smaller (200 - 2,000 ac-ft) storage opportunities.

3.1 SCREENING OF POTENTIAL SITES

The objective of this study was to identify small reservoir opportunities that could be utilized to
provide storage to satisfy short- and long-term water demands. A small reservoir was categorized as
capacity of 200 to 2,000 ac-ft. A small reservoir can be built on much smaller streams than a larger
site. In addition, the inflow hydrologic requirements are much less stringent. Consequently, there are
a significantly greater number of smaller sites than larger sites, potentially on most tributary streams.

3.1.1 Preliminary Screening

To reduce the number of possible sites to a manageable size, a preliminary screening was conducted
that evaluated existing and potential irrigated agriculture. This primary screening criterion assessed
whether or not a watershed had existing irrigated agriculture or the potential for future irrigated
agriculture (including the possibility of historic irrigation being reactivated). The Division 6 Engineers
Office maintains records on active and historic irrigated agricultural acreages. Division 6 water
commissioners were consulted to detennine the likelihood of historic acreages being reactivated A
second screening criterion was water yield. A third preliminary screening criterion was cultural
and/ or political considerations. Table 3, Strwns Eliminated firm Further Consideration Du?ing tlr
Preliminary Scnming Process, presents the 28 streams that were eliminated due to a lack of irrigated
agriculture, inadequate hydrology, and! or cultural/political considerations.

3.1.2 Detailed Screening

Following preliminary screening, review of existing documents, discussions with local water managers,
and map reconnaissance efforts were conducted. Consequently, 50 tributary streams with potential
small reservoir opportunities were identified. The 50 tributary watersheds contained approximately
106 potential sites. Several of these potential sites were identified in previous studies, and had been
eliminated as potential storage sites because they did not meet storage capacity criteria (Hydrosphere,
1993; Kent Holt, personal cormmmication, 1999). In addition, several sites that had previously been
regarded as much larger capacity sites were examined in this study. It may be feasible to construct
smaller reservoirs at these sites. Table 4, PotenJ:ial Small ReseYWir Sites Subject to Additional Screening,
identifies the remaining 106 potential sites that were further evaluated and screened.

In this more detailed screening process, various site-specific criteria that might affect potential future
development were evaluated. Among the criteria evaluated were water demand, inflow hydrology,
environmental/1and-use flaws, recreational potential, and the ability of the reservoir at the site to
deliver sufficient water to meet the demand Project costs were not developed or used as evaluation
criteria. A discussion of these criteria is presented below.

I W.'lI'7'lOjJ~&.",Ds...+(Dot{tRpt.1HJ.9,))
J2177/'J9SLW

Montgt:mI?ry WaWn Mining ero.q, ,. p.o. &x 774018 ,. SI'I!ttn1ixJat Spring5, Colorado 80477 ,. [phone]