1987-12-01_PERMIT FILE - C1981017 ‎(111)‎

• Permit No: C1981017
• IBM Index Class Name: PERMIT FILE
• Doc Date: 12/1/1987
• Doc Name: Morrison Knudsen Haul Road Drainage Control Plan
• Section_Exhibit Name: Chapter II Attachment 2 to Appendix II-B-7
• Media Type: D
• Archive: No

TABLE 2
COMPUTATION OF PEAK DISCHARGES AND CULVERT CAPACITIES FOR ROAD SYSTEMS AREA
NIvert Installations
ltxisti" Man. Meter taisting Ratio of
Drainage Ties s[ leak 10-Tr/N-Mr 10-Tr/24-0 Peat Culvert Depth = Culvert Actual to
Culvert Area csaeentratiss ?"nett Mato Rainfall Curve Ru ott Discharge Diameter at Inlet Capacity Rmpired
Number (Sq. Mi.) Mean) (cfa/M12/la) (Inches) Number (Inch"► (eta) (Inches) (Pt•) (eta) capacities
(1) 12) (1) a► (s) (6) (7) ID) (9) uo) (111 1121
A-1 9.94 0.75 390 1.9 63 .08 310.0 144 13 1130 3.6
A-2 0.01 0.25 720 1.9 64 .09 0.9 36 4 45 50.0
� . A-3 0.01 0.25 720 1.9 61 .06 0.6 36 4 45 75.0
A-4 0.02 0.25 720 1.9 61 .06 0.9 24 3 18 20.0
A-5 0.03 0.25 720 1.9 61 .06 1.1 24 3 18 16.4
A-6 1.47 0.33 630 1.9 64 .09 83.0 120 11 740 8.9
B-1 0.04 0.25 720 1.9 63 .08 2.2 24 3 18 8.2
B-2 0.08 0.25 720 1.9 67 .14 8.1 24 . 3 18 2.2
C-1 1.87 0.25 720 1.9 67 .14 188:5 120 11 740 3.9 "
C-2 0.03 0.25 720 1.9 79 .46 9.3 24 3 18 1.9
C. D-1 0.04 0.25 720 1.9 67 .14 4.3 36 4 45 10.5
1
E-1 0.03 0.25 720 1.9 61 .06 1.4 24 3 18 12.9
E-2 1.45 0.33 630 1.9 64 .09 82.0 96 9 440 5.4
i E-3 0.02 0.25 720 1.9 61 .06 1.0 36 4 45 45.0
F-1 0.01 0.25 720 1.9 64 .09 6.3 36 4 45 7.1
( F-2 0.02 0.25 720 1.9 64 .09 1.5 36 4 45 30.0
G-1 0.08 0.25 720 1.9 64 .09 5.2 18 2.5 10 1.9
G-2 0.05 0.25 720 1.9 64 .09 3.2 18 2.5 10 3.1
G-3 0.01 0.25 720 1.9 64 .09 0.& 18 2.5 10 16.7
G-4 0.20 0.25 720 1.9 64 .09 13.0 42 4.5 63 4.8
G-5 0.92 0.25 720 1.9 63 .08 53.0 48 5 86 1.6
G-6 2.26 0.33 630 1.9 64 .09 128.1 72 7 220 1.7
G-7 0.01 0.25 720 1.9 61 .06 0.5' 24 3 18 36.0
G-8 0.61 0.25 720 1.9 61 .06 0.6 24 3 18 30.0
G-9 0.02 0.25 720 1.9 64 .09 7.0 24 3 _18 2.6
G-10 0.60 0.25 720 1.9 64 .09 39.0 72 7 220 5.6
G-11 0.49 0.25 720 1.9 64 .09 32.0 36 4 45 1.4
i G-12 1.02 0.25 720 1.9 67 .14 101.0 72 7 220 2.2
1 2.34 0.42 560 1.9 63 .08 105.0 -- -- -- --
2 4.47 0.50 500 1.9 64 .09 201.0 -- -- -- --
j .
Explanation of Columns:
(2), (3) -- From Table 1
�i (4) -- From Figure S-1, Reference 4
(5) -- From Figure 2 for 24-hour (1440 minutes) duration and 10% probability
� . (6) -- From Figures S-2, S-3 and S-4, Reference 4
(7) -- From Figure S-3, Reference 4 for 1.9 inches of rainfall
(8) -- Col. (2) x Col. (4) x Col. (7)
(10) -- Pond depth at inlet equal to level one foot above top of culvert
(11) -- From Chart 5, Reference 7= assuming Inlet Control with Type (3) entrance
j (12) -- Col. (11) Col. (8)
J
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