STUDY OF GONGGANG RESERVOIR OPERATION IN MAGETAN REGENCY EAST JAVA PROVINCE

• Main Author: SETYO NUGROHO (NIM 95006014); Pembimbing: Joko Nugroho, ST., MT., PhD., dan Ir. Winskayati, Sp., HERU
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13530
• Institution: Institut Teknologi Bandung

Gonggang Reservoir lays in path Kali Gonggang, one of Madiun tributary which administratively resided in Genilangit Village, Poncol District, Magetan Regency East Java Province. The distance is about 15 kms of downtown southwest Magetan. This location below the authority of Balai Besar Wilayah Sungai Bengawan Solo. The reservoir was build to overcome lacking of irrigation water and standard water for public in service region at dry season and it is expected to be able as one of the recreation purpose place in Magetan regency. In its operation, water which is accommodated in the reservoir must be utilized optimally to fulfill the demand in various sectors. To achieve the purpose, hence it is required a study about reservoir operation. In the study of this reservoir operation involves rainfall analysis, water availability analysis by using a method developed by Scientist Group of Water Resources Engineering at Bandung Institute of Technology, reliable surcharge analysis, and demand analysis for various needs such as irrigation and amount of drinking water required for the resident. By using water equilibrium and maximum and minimum limitation that can be accommodated (effective accommodation), it is obtainable the rice field wide area that can be cultivated in each of planting period. From the previous study it was gotten that sedimentation speed per year in Gonggang river basin area of 5.148,69 m3/year. With intake elevation +787 m, it was obtained accommodation volume of 295.612,59 m3. From the calculation it was obtained the reservoir life of 57,42 years, so it is longer than plan life of 50 years. From the study of the reservoir operation which has been done by using water for irrigation and amount of drinking water required (number of resident according to projection year, served 100%), it was yielded that the rice field wide area which can be served in the year 2007 is 1270 hectare during planting I, 465 hectare during planting II and 115 hectare during planting III (palawija). While at projection of the year 2032 the rice field wide area which can be irrigated is 1260 hectare during planting I, 475 hectare during planting II and 95 hectare during planting III (palawija).