Hydrological Analysis of Kadumalik Reservoir Design To Fulfill Water Demands of the Plan In the Cilutung IA (Irrigation Area)

Abstract

The Kamun Irrigation Area or formerly better known as the Cilutung Irrigation Area (West and East) covering an area of 8,642 ha utilizing water from the Cilutung River through the Kamun Dam. At present, the intensity of planting in IA (irrigation area)at Kamun reaches only 211% with the main cropping pattern being rice-rice-crops. When looking at the potential availability of water in Kamun Dam, the amount of cumulative water availability per year (1,165 million m3 / year) still far exceeds the total irrigation water needs of Kamun IA (299 million m3 / year). The water balance deficit in Kamun Dam occurred in the period from the end of May to the end of November. The solution to overcome the fluctuations in water availability that is not in line with the fluctuations in water needs, namely by building reservoirs that that have one of the potential in Kadumalik. With the Kadumalik Reservoir it is expected that cropping intensity can increase by 300%. Based on the results of the hydrological analysis, the construction of the Kadumalik Reservoir in the Cilutung watershed can have a significant impact on the supply of irrigation water and raw water requirements. In addition, as a reduction in flooding downstream of the dam by 37.6% (when 20 years return). Kadumalik Reservoir has a reservoir capacity of 35.67 million m3 which can be used to irrigate an area of 8,462 Ha. Irrigation water needs with the pattern of planting rice-rice-crops, the amount of irrigation water needs is 2.5 m3 / sec. The Kadumalik Dam is also planned to meet the raw water in Majalengka and Cirebon Regencies with the amount of water needed for MRI (Master Requirement Plan) is 4.5 m3 / sec.