Question

A detention basin for storing stormwater runoff from a proposed shopping center site development plan is excavated from a level portion of the site. The basin is rectangular in shape, 145 feet wide, 270 feet long, and 8 feet deep from top of the excavation to the bottom, which is flat. Assuming the side slopes of the basin are 3:1 (H:V), (a) how many cubic yards of earth were removed in the excavation of the pond (15 points), and (b) how many gallons of stormwater can be stored in the basin if it is filled to a depth of 6.5 feet (15 points)?

Answer 1

340 Soluuhon lon3 fendh aft 3 aaaft aft depth a fed l width art tlon 145-axa qチ 39150 Ft Total Voume A jtAal x depth : | 391 50-t al 53H + 2153 total Volume extavated b> 그f the depth is 6.5 feet 3 aaart3 Coss Secion asea at the water leve l 36t x131 3535 Ft total Volume oc wateㆆ -| A at A31 x depth of upated I5 314 3535x65 s our l13 84 allon of wates Scanned with CamScanner CS