The effectiveness of using a recharge well to mitigate flood measured in a physical model

Abstract

A structural method that involves the use of a recharge well to mitigate flood in a flat area is adopted as a mitigation method for this research. The determination of the effectiveness of this method was carried out by simulating storm-water accumulation in a reduced scaled physical model. The physical model had a rainfall simulator fitted to a sand tank which contained soil materials of different grain size and different coefficient of permeability. Size of the sand tank is 100 cm 60 cm × 40 cm and a perforated pipe of 3.5 cm are fixed in the model to simulate recharge well. By varying the rainfall intensity and rainfall duration a relationship was established between the rainfall characteristics and movement of storm-water into the ground. An average of 43.3% increase in recharge rate was observed when the model was tested with the recharged well as compared to a condition in which recharge well is not present. The reduction in rainwater when the recharge well exists is 6.07% of the total rainwater .