Infiltration Well Planning to Improve Water Conservation and Reduce Runoff in Residential Area

As one of the natural resources, water needs to be conserved so that its quality and quantity can be guaranteed. For this reason, efforts need to be made so that large amount of water is expected to seep into the soil so that runoff can occur as minimal as possible. The development of settlements in urban areas has increased, resulting in reduced rain catchment areas. Increasing built up areas causes an increase in runoff. This study aimed to plan the dimensions of infiltration wells and calculate the effectiveness of infiltration wells in reducing runoff. The construction of these infiltration wells was an effort to increase the infiltration of rainwater into the ground and minimize runoff that may occur. This research was conducted in a residential area in Bogor Regency, West Java. The analysis was carried out based on rainfall data for the last 10 years, i.e., 2009–2019 and the applicable standards in Indonesia for the manufacture of infiltration wells (SNI 03-2453-2002). The planned rainfall was 126.05 mm/day, whereas the soil infiltration rate was 12.4 cm/h. For this reason, wells were planned with diameter of 1.4 m and depth of 2.3 m, so that a total of 206 infiltration wells were required in the housing location. With the presence of infiltration wells, the coefficient of runoff decreased because some of the runoff will enter the infiltration well, especially from rain falling on the roof. The construction of infiltration wells could reduce runoff discharge by 346.02 m3/h or 56% of the existing runoff. The development of infiltration wells was an effort to increase the amount of groundwater artificially as well as to slow down the occurrence of runoff downstream, because some amount of water will be retained in the infiltration well.