24 ‎(3)‎

• Board Meeting Date: 5/21/2008
• Description: ISF Section - Injury with Mitigation - Case No. 5-07CW210; Application of Vail Associates, Inc. and the U.S. Forest Service
• Board Meetings - Doc Type: Memo

Mitigation Improvements to Two Elk Creek
Vail Associates has agreed to design and construct three stream habitat improvement structures
in Two Elk Creek at suitable locations within the stream reach extending from the confluence of
the Tea Cup tributary drainage downstream for a distance of 300 yards. These structures will be
designed to create new pools, enhance existing pools, or deepen the channel so as to improve the
hydraulic conditions of the stream for fish habitat during periods of low streamflows. The design
and construction of the stream habitat improvement structures will be conducted in consultation
with the Colorado Division of Wildlife ("CDOW") and subj ect to approval by the U. S. Forest
Service ("USFS") and the U.S. Army Corps of Engineers.
Vail Associates plans to coordinate with USFS and CDOW staff for a field reconnaissance to
identify stream habitat improvement areas. The first field visit should occur in July 2008 with
additional field visits as necessary. The structures should be installed in the late summer and fall
of 2008. Because of USFS's concerns for this ecologically sensitive area, the structures may
need to be installed by hand or with light weight machinery. Applicant will not operate the well
before completion of the restoration structures. Applicant will perform necessary maintenance
on the structures as long as the snowmaking well is in operation, and will allow the CWCB and
CDOW a right of access to the area for the purpose of inspecting the stream habitat improvement
structures.
It is anticipated that these restoration efforts will improve the hydraulic conditions of the stream
and increase the ability of Two Elk Creek to sustain aquatic biota and the natural environment
with lower flows.
Operational Limitations on Well Pumping
Vail Associates has devised a plan to minimize impacts of the well depletions on Two Elk Creek.
Rather than pumping continuously, the well will be pumped in 10-hour intervals. This will allow
Two Elk Creek to partially recover for 14 hours each day. The purpose of this plan is to spread
the impact of pumping over a longer period of time. For the same volume of depletions, the
depletion rate is minimized, resulting in a reduction of the impact on streamflow. The maximum
pumping rate of 15 gpm will not impact Two Elk Creek at 100%, but rather the percent of
pumping rate impact on the stream will fluctuate between 57% and 27% each day. The
maximum well pumping impact is 0.019 cfs and will only occur for a few hours at a time while
the well is pumping, during November and December.
Extent of proposed injury
The alluvial snowmaking well that is the subject of this injury with mitigation proposal is known
as the Tea Cup Bowl Well. The Applicant has proposed this well as the least environmentally
damaging alternative to develop a water supply for snow making in this part of the ski area. The
well will be placed at a distance of 120 feet from Two Elk Creek.
Depletions from the Tea Cup Bowl snowmaking well will not impact streamflows in the Eagle
River below Two Elk Creek so long as the augmentation plan by exchange is operated properly.
As part of the augmentation plan by exchange, Vail Associates seeks approval to release up to
one acre-foot (the maximum depletion) of water from Eagle Park Reservoir, plus the amount
required for transit loss, to the Eagle River to replace all of the depletions from the well, thus
preventing injury to any downstream water rights on the Eagle River and Colorado River below
Two Elk Creek.
The extent of depletions to Two Elk Creek would not exceed one acre-foot of water per year.
Under the proposed operating plan for the Tea Cup Bowl Well, pumping would be limited to 10