7397

• UCREFRP Catalog Number: 7397
• Author: Resource Consultants, I.
• Title: Draft Supplement to the Final Environmental Statement Colorado-Big Thompson, Windy Gap Projects Water Marketing Program for Green Mountain Reservoir, Colorado.
• USFW Year: 1985.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

DESCRIPTION OF THE ALTERNATIVES

Alternative 1, "No-Action Alternative. This alternative reflects the present
reservoir operational practices under Senate Document 80. This will be
considered the baseline condition in that use patterns based on historic flows
would continue. Water may continue to be available for interim contracts, but
there would be no long-term contracts for water sales. Environmental impacts of
such sales would be addressed on a year-by-year, case-by-case basis.

Alternative 2. Full Sales/Exchange with only Hydrologic Constraints. Under
this alternative the impacts of full sales or exchange to meet all of the
currently identified requests for water (approximately 22,800 acre-feet) are
evaluated. A review of the requests for water from Green Mountain Reservoir
revealed that many requestors are located above Green Mountain Reservoir in the
Blue River drainage or on the Fraser or Eagle river systems. For these
requestors, diver~ions and/or depletions would be made to the flow of small,
upper watershed streams, and corresponding releases from Green Mountain
Reservoir would replace the depletion to the Colorado River system below the
reservoir. Water sales to these requestors imply an exchange of water above
Green Mountain Reservoir.

Under this alternative, the physical (hydrologic) constraints of the system to
deliver requested water sales will be assessed. Essentially all water requests
will be met except where streams are physically incapable of delivering the
amount of water at the time requested. At this level of water sales a shortage
of from zero to 30 percent might have to be imposed in some months of some
years,

Alternative 3, Full Sales/Exchange with Instream Flow Constraints. This
alternative considers the same level of water sales (22,800 acre-feet) as
Alternative 2, however, currently recommended or appropriated instream flows by
the Colorado Water Conservation Board represent an added constraint on the
diversion or depletion of streamflow. This added constraint could be
particularly important for those water requestors anticipating use of Green
Mountain water as a basis for exchange from the smaller, headwater streams in
the Fraser River, Blue River, and Eagle River drainages. Under this
alternative, some water requests would not be met in full during some months of
some years. As with Alternative 2, a shortage of from zero to 30 percent might
have to be imposed in some months of some years.

Alternative 4, Expanded Sale~resenting Maximum Water Sales from Green
Mountain Reservoir. This alternative assumes approximately a 25 percent
lncrease in demand over Alternatives 2 and 3 to a level of 28,800 acre-feet
annually, Under this alternative, the physical (hydrologic) constraints of
Green Mountain Reservoir and the downstream river system to deliver water at
maximum capacity will be assessed. At this level of sales, a shortage of from
20 to 50 percent might have to be imposed in some months of some years.

Such a level of demand might be generated by expanded industrial (e.g., oil
shale) requirements for Green Mountain water, For Alternative 4, the
incremental increase from the full sales level (22,800 acre-feet) to the
expanded sales level was assumed to represent a demand below Green Mountain

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