2012-12-21_REVISION - C1996083

• Permit No: C1996083
• IBM Index Class Name: Revision
• Doc Date: 12/21/2012
• Doc Name: Adequacy Review Letter
• From: DRMS
• To: Bowie Resources, LLC
• Type & Sequence: TR76
• Email Name: SLB
• Email Name: SB1
• Media Type: D
• Archive: No

Page 3 of 4
Culverts:
Diameter
Diameter
p App. B-
SEDCAD
2
F2
42"
30"
Please revise the table to coincide with the SEDCAD report on pages App. a -17 through
App. B -41.
10. Page App. B -6 indicates that the anticipated runoff from the 10 yr -24 hr event to Pond F is
3.74 ac ft. We are unable to locate supporting documentation, such as a SEDCAD run or
other calculation, for this runoff estimate. Please provide the SEDCAD report or other
information to document the runoff calculation for the 10 yr -24 hr event.
11. Pond F, as designed, appears to be adequate to contain the 10 yr -24 hr storm event (3.74
ac ft), with storage capacity for approximately two years of sediment accumulation (0.20 ac
ft). There is an additional 0.03 ac ft of excess capacity in the pond, which equates to
roughly 5945.1' elevation. Because there is so little excess capacity in Pond F, it will be
imperative that the pond be maintained so that water and sediment are at or below 5945'.
Upon approval of TR -76 and prior to implementation of the revision, BRL must install a
durable marker in the pond that clearly indicates the 5945' elevation so that
maintenance personnel can identify when the pond will require pumping and /or
sediment cleanout.
12. Page numbers are missing for the designs of ditches F3, F5 and F6; presumably they would
be App. B -19, App. B -21, and App. B -22. Please revise these pages to include page
numbers.
13. Page App. B -24 indicates that the discharge at Ditch D -F7a is 26.80 cfs. The SEDCAD run on
page App. B -16 indicates that the discharge is 33.44 cfs. It appears that the 26.80 cfs value
was a holdover from the calculation for Ditch D -F4 on page App. B -20. Please revise the
calculation on page App. B -24 to coincide with the runoff figure calculated on page App.
B -16.
14. There appears to be a conflict on Pages App. B -2 and App. B -30 as to whether Ditch D -F13
will be trapezoidal or triangular. Page App. B -2 indicates that it will be triangular, but the
design on page App. B -30 is for a trapezoidal ditch with 0.0' bottom width. Please clarify
the dimensions and configuration of Ditch D -F13 and revise the pages for consistency.
15. Page App. B -41 indicates that the overall slope for the West Diversion Ditch #1 will be
2.0 %. This appears to be accurate for the overall ditch length, but does not consider the
steeper section of the ditch that runs north /south parallel to the D -F21 and D -D3 ditches.
The Division estimates, based on the anticipated discharge of 5.99 cfs and the design
configuration provided by BRL that velocities will be in excess of 6 fps at slopes greater
than or equal to 13 %. Please include an additional design for the segment of the West
Diversion Ditch #1 that exceeds 13% slope.