a Figure 3.1 : ( a ) Typical Section of Swale ( b ) Constructed Swale at Site A
Design and Materials for BIOECODS b
Swale is designed as a dual-layer conveyance system . As runoff accumulated at the surface , it first infiltrated into the sand layers and then the sub-surface modules . This infiltration provides both quantity and quality treatments to the runoff . While the surface of the swale is generally not much larger than that of the conventional drain , the total cross-sectional area of the system provides a much larger water storage and treatment function than a normal conventional drainage can offer .
Excess stormwater is also stored in the dry ponds which were constructed with a temporary storage function . The dry pond is essentially an On-Site-Detention ( OSD ) pond , which has been integrated with the swale to temporarily store the stormwater runoff . The drainage cell is placed beneath the dry pond where the stormwater is drained out by infiltration . Dry ponds diffuse flow
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