Optimizing the Irrigation Water Needs of Lebak Semendawai Swamp in Increasing Agricultural Production

East OKU Regency, South Sumatra Province, Indonesia, is a region that has great potential in the agriculture and plantation sectors. Utilization of swamps and tidal swamps is used as an alternative to increasing agricultural yields despite extreme changes in river water flow downstream during the dry season. This study aims to analyze the magnitude of the potential discharge mainstay, and the influence of the magnitude of the flow of the Komering river flow to the availability of water and the availability of optimum discharge in the Lebak Semendawai irrigation area. The total area of 1,218.83 hectares of rice fields, 374.9 hectares is a shallow swamp. Based on rainfall data for the last ten years, it shows that the potential for discharge is 2.67 m3 /sec, while the required water needs is 2.16 m3/sec. (excess water is 0.51 m3/sec). The results of the analysis show that the planned cropping patterns that can be applied are Paddy - Paddy – Secondary Crop. The Komering river water discharge which affected the first cropping rice planting pattern was 62.877 m3/sec, the second rice planting period was 43.41 m3/sec and during the cropping period the water demand could be fulfilled, if it was achieved through pump system with a capacity 1,657.6 liters/sec because the water level of the river from June to November are under the baseline elevation of floodgate on retrieval buildings. Water requirements for the entire irrigation network system in the Lebak Semendawai marsh swamp are 37.22 m3/sec.