Analysis Of Water Availability In The Environmental Water Sources Of The Aikmampat River Sub-Region In Fulfilling The Need For Clean Water In The South Part Of Lombok Island

Abstract

Clean waters infrastructure functions in utilizing water resources for the general public. General planning for clean water development in this study is focused on water resource management in the form of stewardship, provision, use, development, and exploitation of water resources considering that the social, environmental, and economic functions of water resources cannot be separated. To estimate water availability for biota or ecosystems, we use the discharge at Q-95% at each weir. To analyze waters availability for biota, we refer to the flow duration curve graph. We have calculated the water balance for the Lingkung sub watershed of Aik Mampat, taking into account the surface water sources. The water balance has been calculated under two conditions: existing conditions (which include needs of irrigation and existing water needs of raw) and planned conditions (which consider the development of a drinking water management system). The level of service in the south coast area for 5 sub-districts in the development plan year was obtained at 150 l/s and a maximum of 270,75 l/s in the plan year. The maximum irrigation water requirement is 320 l/s with an average of 50 l/s. The water balance in the Aikmampat Sub-watershed (Lingkung surface water source) saw a decrease in the minimum FK (Reliability Factor) from the existing condition of 40% to 25% (plan condition). Water rotation arrangements in the spider channel need to be carried out, especially in June and July.