Alokasi Air dan Pengembangan Prasarana Penyediaan Air Baku di DAS Ciliman

Abstract

WEAP is one of the hydrological software in evaluating and planning the water balance of a region. The WEAP approach method operates with the basic principle of water balance and allows the creation of scenarios based on existing conditions to investigate the impact of policies or alternative assumptions in the use and availability of water in the future.The purpose of this study includes; (1) Analyzing the potential availability of raw water in each Ciliman Sub-watershed, (2) Analyzing the raw water needs of the Ciliman watershed, (3). Analyzing water allocation for each raw water requirement in the Ciliman watershed to be fulfilled and (4). Analyzing the potential for developing raw water infrastructure in the Ciliman watershed. The types of data used in this study are secondary data including: (1) monthly rainfall data from the Ciliman reservoir rainfall observation station, Gunung Kencana, Bojong Manik and KP3 at year 1998 - 2015, (2 ) population data of Ciliman watershed region, (3) the amount of raw water needs data, (4) Irrigation networks around the Ciliman watershed data (5) maps of the Ciliman watershed, (6) Tools used in this study include computer units and WEAP software.The resultsof the analysis shows that the existing simulation for domestic water needs can be fully fulfilled (100%) until the simulation time in 2036 for all sub-districts around the Ciliman watershed, except in August, the following sub-districts are not 100% fulfilled: Cirinten Subdistrict water deficit and only fulfilled 0.04%, Gunung Kencana Subdistrict only fulfilled 99.93%, Sukaresmi Subdistrict only fulfilled 11.69% and Panimbang Subdistrict only fulfilled 84.36%. The water needs of the Munjul industry in September to July are 100% fulfilled, while August is fulfilled by 40.55%. The water needs of KEK Tanjung Lesung and South Banten Airport from October to July are 100% fulfilled, while August is fulfilled 5% and 0.01% and September 30.27% and 30.60%.Irrigation water needs in the small irrigation area are 100% fulfilled in Planting Season (Rice) (1st week of October - 1st week of February) and in planting season II (Rice) (2ndweek of February - 2nd week of June), except irrigation in the Cipanggelangan watershed on MT I (November) fulfilled 57.80% and in MT.II (May) fulfilled 98.29%. Kramatjaya pump irrigation in MT I (November) was fulfilled 93.56% while in planting season III (Crops) (1st week of June - 2nd week of September) could not be fulfilled. The water needs of the Ciliman Irrigation Area are 100% fulfilled in October to June except in November only 92.10% is fulfilled, while the July to September deficit is only fulfilled by 36.16%, 3.18% and 32.85%. With the scenario of dam development with 4 alternatives, it can reduce the number of water supply failures until year 2036, so that raw water needs for various purposes can be fulfilled.