PERMFILE64795

• Permit No: M1999098
• IBM Index Class Name: Permit File
• Doc Date: 2/25/2000
• Doc Name: RIVERVIEW RESOURCES 112 APPLICATION CAMAS COLORADO INC DMG M-99-088 HYDROLOGIC RIVIEW 2ND ADEQUACY
• From: TUTTLE APPLEGATE INC
• To: DMG
• Media Type: D
• Archive: No

• •
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71uttleApplegate,lnc.
Consultants for Land, Mineral and Water
February 25, 2000
Mr. Tom Schreiner
Division of Minerals and Geology
1313 Sherman Street, Room 215
Denver, Colorado 80203
II1 IIIIIIIIIIIII III
RE: Riverview Resources 112 Application, CAMAS Colorado, Inc., DMG No. M-99-088
Hydrologic Review (2"' Adequacy Review)
Dear Mr. Schreiner:
This report is written to address the hydrologic concerns identified in [he 2nd adequacy review of
the above mentioned permit application.
Exhibit D - Mining Plan
There will not be any expected change in the current flowpath of a 100-yeaz flood event /
for the Cache la Poudre River within the affected land boundary or immediately
downstream of the affected land boundary as a result of either the excavations during
mining or the post-mining topography during final reclamation.
lu
2. As each mining cell approaches reclamation, appropriate spillways will be designed by, _ ,~,b°
or under the direct supervision of, a Professional Engineer according to expected water b° j
volumes, velocities, and flows fora 100-yeaz event. These designs will be submitted to
the Division of Minerals and Geology for approval prior to construction
2c. The mining maps have been changed to reflect the commitment of the operator to a
setback distance of 100 feet from [he pit edge to the top of the nearest river band from
October-March and a setback distance of 200 feet from the edge of the pit to the top of
the neazest river bank from April-September. The operator also commits to providing
the DMG a signed affidavit stating that a 200 foot buffer zone is established between
the edge of the pit and top of the river bank yeazly while the permit is active. If mining
occurs within the strip of land that is between 100 feet and 200 feet from the pit edge to
the top of the neazest bank, final reclamation will include a stable backfill to the
original ground elevation within the mined strip and reclamation of the surface of the
fill. Please refer to the attached revised Exhibit L for bond recalculations for the
backfilling.
3. New drain tiles or redundant drain tiles to existing tiles will be constructed as they are
encountered through the mining process. The new drain tiles will be placed at a depth
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