2016-09-16_PERMIT FILE - M2016010

• Permit No: M2016010
• IBM Index Class Name: Permit File
• Doc Date: 9/16/2016
• Doc Name Note: Response #5
• Doc Name: Adequacy Review Response #5
• From: Transit Mix Concrete Co.
• To: DRMS
• Media Type: D
• Archive: No

Table A-4a
Runoff Peak Flow Determination
Hitch Rack Ranch Quarry Project,El Paso County,Colorado
DESIGN STORM 10 Year 1-hr Precip Depth: 1.75 inches
Sub-Basin Direct Total
Data Runoff Runoff
Drainage Area Rational Tc C x A I Q Tc Sum I Q
Basin (ac) Coeff. (min) I (in/hr) (cfs) (min) C x A (in/hr) (cfs)
Pre-Mine Condition
N1 83.48 0.26 29.4 21.70 2.93 63.6 29.4 21.70 2.93 63.6
Ll 37.08 0.26 22.9 9.64 3.37 32.5 22.9 9.64 3.37 32.5
B1 51.66 0.26 29.8 13.43 2.91 39.0 29.8 13.43 2.91 39.0
Cl 51.67 0.26 28.1 13.43 3.01 40.4 28.1 13.43 3.01 40.4
Ol 46.86 0.26 27.9 12.18 3.02 36.8 27.9 12.18 3.02 36.8
E2 23.23 0.26 20.7 1 6.04 3.54 21.4 1 20.7 6.04 3.54 1 21.4
Al 3.38 0.71 10.0 2.40 4.82 11.6
A2 19.37 0.38 19.9 7.36 3.61 26.6 29.9 9.76 4.22 38.2
B1 17.77 0.39 19.6 6.93 3.64 25.2
B2 39.64 0.26 20.7 10.31 3.54 36.5 40.3 17.24 3.59 61.8
Cl 9.25 0.77 17.9 7.12 3.80 27.1
C2 10.62 0.35 14.7 3.72 4.14 15.4
62.7 12.38 4.04 48.7
C3 1.43 0.77 16.1 1.10 3.98 4.4
C4 0.57 0.77 14.0 0.44 4.23 1.9
C5 43.27 0.29 20.7 12.55 3.54 44.5
D1 8.94 0.45 20.0 4.02 3.60 14.5
D2 1.66 0.60 11.7 1.00 4.54 4.5
61.4 6.76 4.15 25.8
D3 1.81 0.77 19.7 1.39 3.63 5.1
D4 0.45 0.77 10.0 0.35 4.82 1.7
E1 4.03 0.32 16.2 1.29 3.97 5.1
37.1 7.06 3.75 25.5
E2 22.2 0.26 20.9 5.77 3.53 20.4
F1 5.3 0.46 24.3 2.44 3.26 8.0 24.3 2.44 3.26 8.0
F2 1.72 0.77 21.9 1.32 3.45 4.6 21.9 1.32 3.45 4.6
GI 6.37 0.41 16.7 2.61 3.92 10.2 16.7 2.61 3.92 10.2
H1 11.01 0.36 29.9 3.96 2.90 11.5
H2 3.29 0.28 18.1 0.92 3.78 3.5
H3 2.8 0.77 29.4 2.16 2.93 6.3 139.4 7.84 3.64 24.7
H4 1 0.53 0.77 13.6 0.41 4.28 1.7
H5 0.51 0.77 13.5 0.39 4.29 1.7
11 1.67 0.77 21.6 1.29 3.47 4.5
12 0.89 0.76 13.3 0.68 4.32 2.9 90.9 3.96 3.90 14.9
13 1.67 0.77 21.5 1.29 3.48 4.5
14 0.94 0.76 13.3 0.71 4.32 3.1
J1 41.43 0.25 28.1 10.36 3.01 31.2 28.1 10.36 3.01 31.2
J2 27.2 0.20 28.0 5.44 3.02 16.4 28.0 5.44 3.02 1 16.4
N1 68.29 0.27 28.1 18.44 2.07 38.1 28.1 18.44 2.07 1 38.1
N2 26.36 0.41 28.0 10.81 2.07 22.4 28.0 10.81 2.07 22.4
01 46.86 0.27 28.0 12.65 2.07 26.2 28.0 12.65 2.07 1 26.2
Phase 11
Al 4.76 0.68 10 3.24 4.82 15.6
A2 57.88 0.41 30.6 23.73 2.86 67.9 40.6 26.97 3.84 83.5
B1 18.24 0.39 19.6 7.11 3.64 25.9 19.6 7.11 3.64 25.9
N1 77.21 0.37 26.6 28.57 3.11 88.7 26.6 28.57 3.11 88.7
N2 34.18 0.41 18.7 14.01 3.72 52.2 18.7 14.01 3.72 52.2
Phase III
A2 57.62 0.44 37.4 25.35 2.51 63.6 37.4 25.35 2.51 63.6
B1 20.29 0.41 19.4 8.32 3.66 30.4 19.4 8.32 3.66 30.4
B2 37.59 0.26 20.7 9.77 3.54 34.6 20.7 9.77 3.54 34.6
N2 24.45 0.55 10 13.45 4.82 64.8 10 13.45 4.82 64.8
N3 30.92 0.63 16.6 19.48 3.93 76.6 16.6 19.48 3.93 76.6
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