Utilization Surface Water for Raw Water and Irrigation in Maros Watershed, South Sulawesi, Indonesia

Abstract

This research is intended to analyze the existing water for the needs of raw water and irrigation.The methodology applied in this research is surface water availability analysis conducted on rainfall analysis result basis and monthly hydrograph flow analysis for one year period. The needs of crude water are determined by the total population and consumption level in a region with and under mathematics method.  Raw water requirement is determined by the total population and consumption level in a region. Average irrigation water requirement in the research area are calculated based on the average use of water for irrigation for one year period. The use of water for irrigation is approximately determined by variable of rice field area width, height of average water surface during the planting, plant age and planting frequency within a year, and efficiency factor (loss). The rainfall analysis result applying polygon theissen at Maros watershed is 2810 mm/year and average rainfall is 141 mm/year. The calculation of monthly debit of Maros River in 1993 through 2012 using the opportunity approach with the reliable discharge is 65.49 m³/sec and the average is 287.56 m³/sec, meanwhile the minimum discharge is 0.14 m³/sec. The projected raw water requirement are 7.42 million m³ for period of 2013-2017 to become 9.02 million m3 for 2028-2032. Further the needs of domestic water for period of 2038-2042 is 10.27 million m3, rises to be 11.69  million m3 in 2048-2052.The projected need of water for irrigation of Maros watershed for period 2013-2017 is 393.91 million m³, increases to be 459.96 million m³ for period of 2018-2022 and rises to be 1165.7696 million m³ for period of 2048-2052.

Keywords: Watershed, polygoh theissen, discharge, raw water and irrigation.