The effect of rainwater injection into dug wells on the changing of ground water level in Kusumanegara Region of Yogyakarta City

Abstract

The rapid growth of the Special Region of Yogyakarta makes the water shortage one of the problems that must be solved immediately. The study area is located between Semaki Gede and Muja Muju Village in the Umbulharjo district of Yogyakarta. Declining groundwater levels and droughts has caused an abnormal environmental behavior, as there are still many flood points when the rainy season arrives. Precipitation (mm) between 1976 and 2018 shows that the potential rainfall intensity of the Yogyakarta has not changed significantly. Therefore, it is possible to take advantage of the rainwater potential of an average of 7.23 mm per month, a maximum precipitation of 210.281 mm in November 2017 and a minimum precipitation of level 0 from May to October 2018. The method used is to load or recharge rainwater in the dug well to keep the groundwater level stable. In this study, GAMA Rainfilter rainwater injection technology was used and 10 excavated wells were used, of which 5 uninjected observation and research wells were excavated and 5 excavated injected observation and research wells. Observation of the groundwater level of 10 wells from 2018 to 2019 resulted in an additional production of 0.095 m or 9.5 cm. Changes in groundwater quality were successful and there are several indicators that need to be considered again in the testing methods process.