REV05308

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 4/14/1999
• Doc Name: HYDROLOGY AS-BUILT DESIGNS TR 86 WEST ELK MINE PN C-80-007 MTN COAL CO
• From: DMG
• To: JIM BURNELL
• Type & Sequence: TR86
• Media Type: D
• Archive: No

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999
STATE OF COLORP~UU
DIVISION OF MINERALS AND GEOLOGY
Departmoln of Nalurol Resources
111 4 Sherman SL. Room 215
Denver, Colurado 80203
Phone: [phone]
FAX: (3113) 83?-810b
DATE: April 14, 1999
TO: Jim Burnell r~
FROM: Joe Dudash ~ r~1 .1/
DIVISION OF
MINERALS
GEOLOGY
RECLAMATION
MINING•SAFETY
tlil I Owens
Governor
Greg E. 1Valcher
Executive Dircao~
m~chael a Eoo~
Dimvon Dueaor
RE: Hydrology As-Built Designs, Technical Revision No. 86, West Elk Mine,
Permit No. C-80-007, Mountain Coal Company
I have finished my review of the hydrology as-builts for the above TR. The following are my
comments or questions. They are in a format so that you can submit them to West Elk as written.
This file is in Wordperfect and is located at m:\coal\jrb\tr86meml
Sylvester Gulch
Please locate or provide the SEDCAD culvert sizing utility designs for culverts CCW-1
and CSLY-20.
2. Please locate culvert CSLY-16 on Map 54.
The SEDCAD drainage basin peak flow design for ditch DSLY-17 shows a peak flow of
20.52 cfs. However, the SEDCAD ditch sizing utility design, and as is stated in
Attachment 44E-1, uses a peak flow of 1.0 cfs for that ditch. Please reconcile this
difference.
4. The SEDCAD culvert and ditch sizing utility designs for ditch DSLY-5 and culvert
CSLY-6 use 3.00 cfs as the peak flow. However, the drainage basin routing diagram on
Map 1 E shows that drainage basins 47C and 49B 1 drain into ditch DSLY-5 and culvert
CSLY-6. The SEDCAD drainage basin peak flow designs show peak flows of 6.26 cfs
and 3.25 cfs for drainage basins 47C and 49B1 respectively. It would appear that the
peak flow to be used in the ditch and culvert designs should be around 6.26 cfs + 3.25 cfs
or about 9.5 cfs. Please comment.