| Runoff Collecting Areas
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| The runoff collecting system is followed the urban grids. The area in blue line is the runoff collecting area for the water garden retention basin. The area in green line is the area for the other retention basin. The blue area is 441074 sq ft and the green area is 397715 sq ft. During a 25 years storm, the peak flow of blue line one is 67.34 cfs and it forms 53940 cubic ft water during 10 minutes period. The other peak flow in green line area is 60.18 cfs and forms 37117 cubic ft runoff in 7.7 minutes. In our project, the volume of the detention basin constructed for blue line area is 20800 cubic ft. The volume of the detention basin in the water play area is 21600 cubic ft. Half of the storm water runoff could be kept by the detention basins. |