Gianyar is one of the regencies which are the main tourist destinations in the Province of Bali, with the icon of the Ubud tourism area which is one of the tourist areas which is already very well known in foreign countries. The increase in tourist visits, both domestic and foreign, certainly brings prosperity to the community and also to the government. Fulfillment of all the necessary facilities for the world of tourism should be a serious concern of the government so that tourists feel at home when visiting Gianyar. One very basic factor that needs serious attention is the availability of clean water. So far, the allocation for non-domestic water needs (schools, government, trade, social and tourism) has only been determined based on the percentage of domestic water needs based on the decision of the Directorate General of Human Settlement with an amount of 20-25% of domestic water needs. Looking at the existing conditions in the field and with the development of tourism facilities, it certainly requires a more accurate calculation related to the predetermined percentage of non-domestic water needs.

The main requirement in recharging aquifers is the quality of refill water must meet the groundwater quality standards. Therefore, the role of the filtration system is important. The horizontal water filtering system has designed to lengthen the filtering process. First step: Rainwater falls that contaminated with various substances flows into the 20 cm thick and 1 m depth of gravels; Second Step: Rainwater continued flowing into the horizontal pipe, 4” of diameter, 20 cm length, with the fibre palm tree inside. The filtered water comes out and collected in a reservoir, flows into a recharge wells with 4” diameter and 32 m depth, and fills the aquifer after going through the soil layer. Laboratory tests shows that the horizontal water filtering system is effective to reduce the content of substances, except the TDS for filtering system in Plaga Village. It decreased from 135.00 uS/cm to 81.90 uS/cm (26.55 percentage) in Tegallalang village, but it increased from 95.00 uS/cm to 154.00 uS/cm (62.21 percentage) in Plaga village, although it still meets to the groundwater quality standard. The increasing of TDS might be cause by gravels or palm tree fibres that not thoroughly cleaned and still contained TDS.