Page 574 - Fair, Geyer, and Okun's Water and wastewater engineering : water supply and wastewater removal

JWCL344_ch14_500-554.qxd 8/7/10 8:56 PM Page 530

Weighted Mean Runoff Coefficient, c (10) 0.508 0.518 0.532 Invert Elevation Lower End (21) 84.28 82.94 81.82

Mean Rainfall Intensity, in./h i (9) 2.56 2.45 2.35 Upper End (20) 86.46 83.86 82.48 25.4 mm/h.

Profile Drop in M.H., ft (19) 0.00 0.42 0.46 0.3048 m; 1 in./h

Time of Flow, min In To Upper Drain End (8) (7) 1.5 20.0 1.9 21.5 1.3 23.4 Fall, Length, ft ft (18) (17) 2.18 340 0.92 340 0.66 440 0.02832 m 3 /s; 1 ft

Velocity, ft/s (16) 3.94 3.35 3.02 28.32 L/s

Illustrative Computations for the Storm Drainage System of Example 14.3
Total
2.19
4.16
7.21
(6)
Tributary Area, Acres, a Increment (5) 2.19 1.97 3.05 Capacity, Slope, ft 3 /s % (15) (14) 3.09 6.42 5.93 2.71 9.48 1.50 0.4046 ha; 1 ft 3 /s

Location of Drain Manhole Number To From (4) (3) 2 1 3 2 4 3 Design ft 3 /s Diameter, in. Total (13) (12) 12 2.85 18 5.28 24 9.02 25.4 mm; 1 acre 0.3048 m/s; 1 in.

Street (2) A A B Runoff, Q Per acre ci (11) 1.30 1.27 1.25

Table 14.7 Line Number (1) 1 2 3 Line Number (1) 1 2 3 Conversion factors: 1 ft/s

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