Modification of Conventional Drainage System Using Recharge Well

One of the popular recharge systems is a recharge well that directly receive rainwater from the roof of the house. In this study, recharge wells will be introduced and analyzed in a modification of conventional drainage. Area for this research was taken in Kimpulan Village, Sleman, Yogyakarta. Input discharge that enters the recharge well used free-flow formula through holes or pipes. The dimensions of recharge wells followed the Sunjoto’s formula, but with T is the time of concentration, not the duration of the dominant rainfall. The result of this study showed that recharge well reduced the maximum discharge and dimensions of the channel. The reduction depends on the diameter of the connecting pipe, the height difference of the water level, depth of groundwater and permeability of the soil in the area. If a diameter pipe of 20 cm and a height difference of 1 m are used, it reduced the runoff discharge more than 17.3%. For the study area, it was not feasible to build additional recharge wells, because it required a large number of wells, approximately 58 pieces, due to very small soil permeability of 3.5.10-5 m/s