PERMFILE123411

• Permit No: M2004067
• IBM Index Class Name: Permit File
• Doc Date: 11/21/2005
• Doc Name: Exhibit 18
• From: Clear Creek District Water Providers LLC
• To: DMG
• Media Type: D
• Archive: No

Memorandum to Corey Hoffmann
November 14, 2005
• Page 6
Colorado wafer laws and regulations governing injury to existing water rights. Rule
6.4.7(4) requires the Applicant to identify the specific source(s) of water and the quantity
to be obtained from each source in order to meet the project's anticipated water
requirements for both mining and reclamation.
Supporting Information: We reviewed the State Engineer's Master We]] list, and data we
obtained from the Black Hawk-Central City Sanitation District's (BHCCSD) well. Using
this information, we estimate that depth to ground water at the MMRR Quarry site is
approximately 30 to 50 feet below the ground surface, which means that ground water
may be encountered on the first bench. (This is different than what the Applicant states
in its August 19, 2005, Response to 2"d Adequacy Review comments. The Applicant
states that "exposure [of ground water] will occur no sooner than removal of the second
bench of material, based on a conservative estimate of groundwater levels (see attached
report submitted by Lyman Henn)." Lyman Henn estimated that ground water will
probably be encountered during mining of a depth of 60 to 100 feet below ground
surface.) The depth to water at the BHCCSD's well was 32 feet in September 2003. The
following table shows the depth to water to various wells that are located close to the
proposed MMRR Quarry site.
•
Permit Number Depth to Water
feet Reported Yield
m Distance to MMRR
ua feet
59840-F 34 15 440
484140-F 16 6 900
29858 - MH 20 --- 450
The permanent removal of the fractured rock reduces storage space for ground water and
reduces the potential recharge to the aquifer which causes a significant disturbance to the
prevailing hydrologic balance. Using pore space volume calculations we estimate that
approximately 16 acre feet of water per year will be removed from the hydrologic
system. The Applicant stated that they are planning to follow the Lyman Henn's
"proposed approach to minimizing effects to the prevailing hydrologic balance" The
Applicant's Lyman Henn report also states that "the quarry will effectively become a
large diameter well." In our review of the Lyman Henn report, we understand that the
proposed approach is to allow the ground water to evaporate. The removal of 16 acre feet
per year is a significant disturbance to the prevailing hydrologic balance and to the
quantity of water in surface and ground water systems and can injure downstream water
rights, including Black Hawk's. For example the BHCCSD well is permitted to produce
15 gpm not to exceed 24.2 acre-feet per year. The removal of the ground water from the
system may cause a reduction in the capacity of the District's well. The evaporative toss
of the estimated 16 acre-feet per year of tributary ground water requires a Substitute
Water Supply Plan or augmentation plan to replace the amount of water that is consumed
(evaporated). We also estimate there will be an initial (one-time) loss of water presently
stored in the area to be mined (10-year plan) of approximately 35 acre-feet.
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LEONARD RICE ENGINEERS, INC.
2000 Cvv STREET, SURE 300. DENVER, COLORADO 8021 1-51 1 8 • PHONE [phone] • FAX [phone]