WSP07965

• File Number: 8446
• Description: Cache La Poudre Project
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 7/1/1983
• Title: Cache La Poudre Project Study and Related Correspondence
• Water Supply Pro - Doc Type: Report/Study

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The principal storage reservoirs in the upper basin are used to store
runoff and transbasin diversions for later release to serve irrigation needs
in the lower basin. Exceptions are reservoirs owned by the cities of Fort
Collins and Greeley. These were originally designed to release flows year
around for diversion into the cities water treatment facilities. with the
availability of Colorado-Big Thompson Project water, the cities use much of
the storage in their upper basin reservoit's for an exchange of waters with
irrigation companies.

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The major storage capacity in the Cache la Poudre River Basin has
been developed in the lower basin in what are commonly referred to as the
plains reservoirs. The lower basin reservoirs are owned by various irrigation
companies and are located below canals owned by these irrigation companies.
These reservoirs are filled with river diversions to storage or storage
releases from upper basin reservoirs. Storage from these reservoirs is
released during the irrigation season to supply irrigation needs to lands
within their service area. In some cases, releases can be made to the Cache
la Poudre River to facilitate exchanges within the basin. The lower lying
plains reservoirs also collect return flows from irrigation in service areas
lying above them.

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Since the time of their construction, reservoirs within the Cache la
Poudre Basin have been uSl!d to accomplish exchanges of water within the
basin. These reservoir exchanges, involving both direct flow rights and
reservoir storage, were well established prior to the 1920's. One reason for
the practice of exchanges i" the relative location of the canals and storage
reservoirs. Another reason is the distribution of priority dates along the
river.

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The extent of water exchanges practiced or contemplated can be seen
from the resume of Water Court Case No. W-8086-75 which lists some 15 pages of
adjudicated exchanges between structures within the basin. In this Case, the
Cache la poudre Water Users Association and its member companies have
adjudicated their historic and contempl.ated exchanges to prevent any future
interference with these exchanges by any junior water rights. The structures
named in the case are by no means an exhaustive list of all possible exchange
combinations, but represent exchanges that either are presently practiced
regularly or have been practiced at certain times for certain durations.

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There are a large number of minor exchanges practiced in the system
that are either made regularly with relatively small amounts of water or which
are made infrequently on an irregular basis. An important factor affecting
exchanges involving Colorado-Big Thompson Project water is a statutory
requirement that Colorado-Big Thompson Project water may not be used outside
of the boundaries of the Northern Colorado Water Conservancy District.

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J. EXISTING POIIBR SYSTEM SB'l'TING

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Since the specific purchaser for the power and energy generation from a
potential Cache la Poudre Project has not been identified at this time, it is

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