2008-06-25_PERMIT FILE - M2008022

• Permit No: M2008022
• IBM Index Class Name: PERMIT FILE
• Doc Date: 6/25/2008
• Doc Name: Mining setbacks from the Yampa River
• From: Allen Sorenson
• To: Russ Means
• Email Name: ACS
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
L N D O
Denver, Colorado 80203 DIO VI A:A
D O F
Phone: [phone] RECLTION
FAX: [phone] MINING
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
DATE: June 25, 2008 Executive Director
Ronald W. Cattany
Division Director
TO: Russ Means Natural Resource Trustee
FROM: Allen Sorenso
v
RE: Mining Setbacks from the Yampa River, 4B land and Livestock, LLC,
Breeze Basin Pit, File No. M-2008-022
Approximately 3.5 acres in the northwest corner of the proposed 19.80 acre pit no. 1 is within zone A of the
floodplain (see enclosed flood insurance rate map). If excavation in this portion of the pit were to be
approved as proposed in the application, flood flows from the river during a 100-year flood would spill into
the pit with the likely result being down cutting and erosion within the mining setbacks and possibly large
scale alteration of the river flow paths in the post flood setting. These types of flow path alterations would
cause off site damage to river banks both upstream and downstream of the pit and might cause damage to
the Deep Cut Ditch. To prevent offsite impacts, the Division requires that these types of pits be excavated
in a way that ensures stability through the floodplain.
The Division can approve a plan that prohibits mining within the floodplain. To do so, the Applicant must
provide maps showing the new extraction limits, and must maintain floodplain boundary markers on the
ground throughout the period of operations for this pit. If the Applicant wants to mine within the
floodplain, technical analysis and designs must be provided for Division review and approval showing how
flood flows could be passed through the pit area without compromising the integrity of the existing
floodplain. This is frequently accomplished by the construction of spillways to convey flood flows from the
river into the pit, such spillways being designed to be non-erosive during peak flood flows. Diking and
levee construction around the north pit perimeter that is with the floodplain would also be effective, but the
Applicant would have to demonstrate that diking within the floodplain is acceptable to the local floodplain
authority, in this case Moffat county, before the Division would approve such a plan.
c:\acs files\My Documents 4-19-06 thru\breeze basin flood review.doc
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines