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

Linda J. Bassi April 29, 2008
Page 2
Location of injury
The proposed structure that is the subject of this Mitigation Proposal is the Tea Cup
Bowl Well No. 1, claimed for 15 gallons per minute (gpm) conditional, with an
appropriation date of June 12, 2007. The source is groundwatertributary to Two Elk
Creek, which is tributary to the Eagle River. The well is to be located within the NW ~/4 of
the SW ~/4 of Section 27, Township 5 S, Range 80 W, 6th Principal Meridian, 1,383 feet
from the South line and 404 feet from the West line of the NW ~/4 of SW ~/4 of said
Section 27. This location is northeast of the base of Chair 36 (Tea Cup Express Lift), as
shown in Figure 1. The Tea Cup Bowl Well is adjacent to an unnamed drainage near
the upper terminus of the 4-mile reach of the CWCB's 4.0 cfs ISF water right.
De Minimus Rule considerations (ISF Rule 8c.)
Under the CWCB's Rules Concerning the Colorado Instream Flow and Natural Lake
Level Program, if "[S]taff determines a water court application would result in a 1 percent
depletive effect or less on the stream reach or lake subject of the ISF" the staff may find
that the depletion would be "De Minimus." If the depletive effect of the proposed well is
found to be "De Minimus" by the staff, then the CWCB would not file a Statement of
Opposition to the application for the water right for the well. In applying the De Minimus
Rule, the CWCB staff uses the amount of the ISF appropriation as the basis for
calculating the maximum allowable depletion (telephone discussion with Bahman Hatami
05/03/2007). Based on this calculation, the maximum (1 %) depletion that would be
considered De Minimus is 0.04 cfs. The impact of pumping from the proposed well at
the rate of 15 gpm (0.033 cfs) is less than the 0.04 cfs flow reduction that would typically
be considered de minimus. However, since there is rarely, if ever, 4.0 cfs at the
headwaters of Two Elk Creek, particularly in the winter, a De Minimus calculation based
on actual flows might be greaterthan the 1% standard.
To avoid a dispute over the proper interpretation of the De Minimus standard, this
Mitigation Proposal serves to define a De Minimus operational scenario that limits
pumping during certain months, and alternates pumping with recovery periods so that
instream flows and aquatic habitat are protected in Two Elk Creek. This proposal
includes additional mitigation that would enable the Board's water right to continue to
preserve or improve the natural environment to a reasonable degree.
Quantification of injury (amount, timing and frequency)
When water is pumped from the Tea Cup Bowl snowmaking well, there would be no
change in streamflows in the Eagle River below Two Elk Creek. As part of the
augmentation plan by exchange, VA seeks approval to release up to one acre-foot 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 hours per day beginning on November 1 St and ending on December 31St
AMEC Earth and Environmental, Inc.