Delineation of Recharge and Discharge Area for Geothermal Energy in Natar

Geothermal is one of the renewable energies which is abundant in Indonesia (∼29 GW). Lampung has several potential areas of the geothermal energy, such as Way Panas, Rajabasa, Sekincau, Way Ratai, Natar, etc, 110 MW potential in total. Natar hot spring is one of the geothermal manifestations located in Natar, South Lampung and included in Metro-Kotabumi Groundwater Basin. This indicates that Natar has potential in geothermal energy. Geothermal energy is known as renewable energy, if only the system can be maintained. One component that can be maintained is presence of water in the reservoir. To maintain this component, recharge area must be known. This paper, provide analysis recharge area delineation based on topographic and geological map. Based on topographic map, recharge area is located at western and at southern part of Metro-Kotabumi Groundwater Basin. The recharge area is located in high terrain topography and covered by volcanic product (intercalation between tuff, lava, and volcanic breccia). Ratio value between recharge and discharge area is 0.17. Due to the recharge area is very small compared to discharge area, it is need to conserve recharge area seriously hence Natar hot spring can be sustainable.