BOARD00125 ‎(2)‎

• Board Meeting Date: 1/24/2007
• Description: ISF Section - Injury with Mitigation - Case No. 1-04CW323, Application of EMJ Squaw Pass, LLC
• Board Meetings - Doc Type: Memo

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water (Vidler Tunnel), non-tributary water (Henderson Mine) and both on-site and off-site storage
to replace expected stream depletions, Until an Augmentation Plan has been approved by the
Water Court, the Applicant has and will seek annual approval by the State Engineer to operate
the Boarding Park under the provisions of a temporary substitute water supply plan (SWSP).

2.0 CWCS STATEMENT OF OPPOSITION

The Colorado Water Conservation Board (CWCB) filed a Statement of Opposition to Echo
Mountain's Plan for Augmentation filed in Case No. 04CW323. The CWCB holds two instream
flow water rights in the Soda Creek basin located downstream of Echo Mountain and above its
confluence with Clear Creek, The rights are located on Little Bear Creek and Soda Creek and
are each decreed for 1,0 cfs, Figure 1 displays the location of the two in stream flow water rights
in relation to the Echo Mountain wells and Clear Creek.

CWCB is concerned that injury could occur to their rights during low flow periods1, Although
Echo Mountain plans to fully augment their expected stream depletions, part of the planned
replacement sources are directly tributary to Clear Creek, not Soda or Little Bear Creeks, As .
such, the CWCB water rights may not receive direct augmentation.

3.0 POTENTIAL INJURY

The wells that serve Echo Mountain were developed deep in fractured Precambrian Biotite
Gneiss (Martin and Wood Water Consultants, Inc.). While these wells are considered tributary to
Clear Creek, the stream depletions will be lagged due to the depth and distance of the wells from
the various streams,

Calculations of lagged depletions were .completed by Martin and Wood Water Consultants, Inc.,
using the traditional SEO-accepted Glover Method, Although this method was not developed for
fractured-rock conditions, it is widely accepted and represents the current standard of care for
calculating stream depletions, The Martin and Wood analysis assumed an average transmissivity
value of 131.7 gallons per day per foot and a specific yield of 5 percent. These assumptions,
combined with the projected pumping volumes at the Park indicate that depletions may not
accrue to area streams for as long as four years. However, for purposes of Echo Mountain's

Water availability projections by the CWCB predict that average streamflows in both
creeks potentially drop below 1,0 cfs during the period November through March,

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