Please give detailed calculation.

Design the outlet structure (box inlet and pipe sizes) of the mechanical spillway for a reservoir using the inflow hydrograph giving below. The runoff depth is 80.8 mm and the peak runoff rate is 6.12 m/s. The maximum allowable elevation of the flood spillway crest is 30.2 m. The reservoir has a watershed area of 50 ha. The box-inlet has a weir coefficient of 1.7, and the length of the pipe is 34 m long with Ke=1.0 and n=0.014. The elevation of the crest of the box inlet is 26.8 m and elevation of the center of the pipe at its outlet is 25.6 m. The cumulative storage available at each 0.6-meter stage above the crest is 0.06, 0.17, 0.41, 0.76, 1.32, 2.10, and 3.22 ha.m.

Time (min) Time Q (m/s) (min) Time (min) Q(m/s) Q (m/s) 0 0 117 3.8 234 0.52 13 0.36 130 3.06 247 0.4 26 1.52 143 2.3 260 0.3 39 3.12 156 1.85 273 0.22 52 4.7 169 1.45 286 0.2 65 5.95 182 1.21 299 0.1 78 6.12 195 0.96 312 0.05 91 5.7 208 0.81 325 0 104 4.95 221 0.65 Time (min) Time Q (m/s) (min) Time (min) Q(m/s) Q (m/s) 0 0 117 3.8 234 0.52 13 0.36 130 3.06 247 0.4 26 1.52 143 2.3 260 0.3 39 3.12 156 1.85 273 0.22 52 4.7 169 1.45 286 0.2 65 5.95 182 1.21 299 0.1 78 6.12 195 0.96 312 0.05 91 5.7 208 0.81 325 0 104 4.95 221 0.65