Example 12.2. As illustrated in Figure 12.4, the layout of sewer system A is located in the City of Denver, Colorado. Use the following information to size the sewer pipes. (a) The 5-year design rainfall intensity, 1 (inch/hr), is given as: I(inch/hr) = 28.5H in which H, = 1.35 inch and Tq=duration in minutes. (10+1)0,789 (6) The overland flow time shall be calculated by the airport formula with the maximum overland flow length of 350 feet. The swale and gutter flow velocities, V, can be estimated by the SCS upland method using a conveyance factor of 20. (c) Information of Subareas: Table 12.1. Hydrologic Parameters for Sewer System A. Area Basin Number Runoff Coeff 1 2 3 4 5 acres 4.0 8.0 3.0 8.5 7.0 0.80 0.60 0.75 0.80 0.85 Overland Overland Channel Slope Length Slope percent feet percent 175 1 2 250 2 2 300 1.5 1 275 1 2 250 1 Channel Length Feet 550 650 350 650 600 Basin 1 Basin 2 250 ft 175 ft 650 ft 550 ft Basin 3 300 ft Basin 4 250 ft 275 ft 12 600 ft 6b0-f 1.0% 350 ft 650 ft Basin 5 650-ft @ 1.0% 42 Notation: 23 Sewer (link) Manhole Manhole (node) (node) Go-f@1.0% Figure 12.4. Layout of Example Storm Sewer System. (d) Information of Sewer Pipes: Table 12.2. Sewer Pipe Parameters for Sewer System A. Sewer ID Roughness 12 Length feet 600 650 600 Slope percent 1 1 1 42 0.014 0.014 0.014 23 down s. C Example 12.2: Additional information (depth of soil cover), soil profile sewer: GSE upstream (ft) Downstream (ft) 0-0 5040 5035 5033 5028 5042 5035 up depth of soil cover 6 5' 8.3" Example 12.2. As illustrated in Figure 12.4, the layout of sewer system A is located in the City of Denver, Colorado. Use the following information to size the sewer pipes. (a) The 5-year design rainfall intensity, 1 (inch/hr), is given as: I(inch/hr) = 28.5H in which H, = 1.35 inch and Tq=duration in minutes. (10+1)0,789 (6) The overland flow time shall be calculated by the airport formula with the maximum overland flow length of 350 feet. The swale and gutter flow velocities, V, can be estimated by the SCS upland method using a conveyance factor of 20. (c) Information of Subareas: Table 12.1. Hydrologic Parameters for Sewer System A. Area Basin Number Runoff Coeff 1 2 3 4 5 acres 4.0 8.0 3.0 8.5 7.0 0.80 0.60 0.75 0.80 0.85 Overland Overland Channel Slope Length Slope percent feet percent 175 1 2 250 2 2 300 1.5 1 275 1 2 250 1 Channel Length Feet 550 650 350 650 600 Basin 1 Basin 2 250 ft 175 ft 650 ft 550 ft Basin 3 300 ft Basin 4 250 ft 275 ft 12 600 ft 6b0-f 1.0% 350 ft 650 ft Basin 5 650-ft @ 1.0% 42 Notation: 23 Sewer (link) Manhole Manhole (node) (node) Go-f@1.0% Figure 12.4. Layout of Example Storm Sewer System. (d) Information of Sewer Pipes: Table 12.2. Sewer Pipe Parameters for Sewer System A. Sewer ID Roughness 12 Length feet 600 650 600 Slope percent 1 1 1 42 0.014 0.014 0.014 23 down s. C Example 12.2: Additional information (depth of soil cover), soil profile sewer: GSE upstream (ft) Downstream (ft) 0-0 5040 5035 5033 5028 5042 5035 up depth of soil cover 6 5' 8.3
