ACTUAL WATER AVAILABILITY AND WATER NEEDS IN IRRIGATION AREA OF RIAM KANAN IN SOUTH KALIMANTAN PROVINCE

Management and utilization of irrigation water in Riam Kanan have a significant impact on availability system and water needs for irrigation and non irrigation (domestic, non domestic, fishery, industry and maintenance of river). This study aims at finding out the potential of water availability and water needs for irrigation and non irrigation as well as delineating the status of water balance in the irrigation area of Riam Kanan. The data used in this study were monthly meteorological data from the year 2002 to 2012, daily rainfall data of 7 stations from 2002 to 2010 in P.M. Noor Watershed and daily rainfall data of 2 stations namely BMKG Banjarbaru and SMPK Sei Tabuk from 1990 to 2012. Besides, the data of catchment area of watershed, planting area and the age of crops were also used. Mock and Nreca methods were used to count water availability to find out the 80% discharge transition in Riam Kanan irrigation area. Meanwhile, standard planning KP-01 of Department of Public Work was used to find out the water availability for irrigation and non irrigation. Water balance analysis in irrigation area of Riam Kanan by using Mock and Nreca methods, by the time the water is needed for irrigation, the water has deficit from May 2012 to September 2012 of 0.21 until 6.56 m3/sec. The results of the study showed that surplus water occurs in wet season and is not used for irrigation. Meanwhile, deficit water happens in dry season, especially for water needs from June until September.