10825 Water Supply Alternative Summary Phase 2 Assessment January 2008 Draft

• Description: A report from the Grand River Consulting Corporation on alternatives for delivering 10,825 AF of water to the 15-mile reach of the Colorado River.
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/2008
• Author: Grand River Consulting Corporation
• Title: 10825 Water Supply Alternative Summary Phase 2 Assessment January 2008 Draft
• Water Supply Pro - Doc Type: Report/Study

the Fryingpan River. Releases from Sulphur Gulch Reservoir would fluctuate more, in order to
optimize flow conditions in the 15 Mile Reach.
Secondary objectives of the study are partially met with this alternative. Releases from Ruedi
Reservoir do not provide any benefits to the Colorado River below Lake Granby. However, with
the release of 5,412 acre feet from Ruedi Reservoir in a base -load schedule, the potential for
impacts to the Fryingpan River are reduced. With half of the 10825 Water released from Ruedi
Reservoir, the Frying Pan River will continue to be an excellent fishery resource that may be
slightly more difficult to access.
As with Alternative A, releases from Ruedi Reservoir would typically occur prior to September
1s`, in order to complement late summer Recovery Program releases from the Green Mountain
Reservoir HUP surplus and from the Wolford Mountain Reservoir fish pool. Any operational
procedures that would allow the release Green Mountain Reservoir HUP surplus water earlier in
the summer, would also allow releases from Ruedi Reservoir to be spread -out over a longer
period of time. This extended release period would decrease any negative impacts associated
with this alternative.
8.4 LAKE GRANBY PARIED WITH RUEDI RESERVOIR (Alternative C7)
This alternative pairs releases from two existing reservoirs. Lake Granby releases of 2,700 acre
feet would occur in the late summer of each year. The remaining 8,125 acre feet of Recovery
Program water would be released from Ruedi Reservoir. This is a non - structural alternative,
however the viability of Lake Granby as a source of 10825 Water is not known at this time.
This alternative provides substantial secondary benefits. The annual release of 2,700 acre feet
from Lake Granby would significantly improve the aquatic resources of the upper Colorado
River, particularly from Lake Granby downstream to Troublesome Creek. In future years when
contract water releases from Ruedi Reservoir increase, the concurrent release of 8,125 acre feet
from the reservoir will cause incremental negative impacts to recreation use and aquatic habitat
of the Fryingpan River. However, the Fryingpan River will continue to be an excellent fishery
resource. With the release of 8,125 acre feet of Recovery Program water, the Fryingpan River
may be slightly more difficult to access for several weeks each summer.
Any operational procedures that would allow the release Green Mountain Reservoir HUP
surplus water earlier in the summer, would also allow releases from Ruedi Reservoir to be
spread -out over a longer period of time. This extended release period would decrease any
negative impacts associated with this alternative.
10,825 V ater S ppJy Study Phis€ 2 Alternatives Assessment Januuy 2008 Draft 18