STUDY OF FLOOD CONTROL OF BATURITI RIVER (TOPEAU) AT IRRIGATION AREA OF PARIGI MOUTONG DISTRICT

• Main Author: Syamsu, Fijri
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/39939
• Institution: Institut Teknologi Bandung

Baturiti river (Topeau) plays an important role having watershed about 62,3 km2 with the length of main river about 19,86Km stretching from the upstream from Jatilueh Mount through Balinggi and Torue sub districts and boiling down to the Gulf of Tomini. The condition of Baturiti river (Topeau) has had narrowing and river flow changing in some points especially the downstream. Therefore, in the rainy season the water discharge overflows and floods the surrounding area. Flash floods happened in 2013, 2014, and 2017 where there is flood inundation in settlements, rice fields,plantation, bridge, and road precisely in Balinggi, Balinggi Jati, and East Tolai villages. The area of waterlogged rice fields and plantation were about 600 Hectares. Flood control efforts are needed to decrease the risk of flooding through initial flood control applying structure method. Flood control study was applied with flood discharge of 25 years return period plan by applying software Hecras 5.0.6 Alternative of flood control that was evaluated was the combination from embankment (H=+0.50m to 2,10 m) and normalization (widening the river channel increases to 15,00 m). Based on hydrodynamics simulation result of the embankment height and normalization can flow the flood discharge of 25 years period safely. Whereas non structural flood control effort is structuring riverbanks/floodplain management, watershed management, dissemination of flood information to the society and determination of river border boundaries The economy analysis result of flooded paddy rice cultivation gained the Benefit Cost Ratio (BCR) value of 0.385 which is not economically feasible. However, in the 20-year payback period it is gained the Internal Rate Return (IRR)value = 15.091 > 8% (normal loan) and Economic Internal Rate Return (EIRR) = 8.011 > 6% (soft loan). Thus, the activity of flooded paddy rice cultivation with the construction of embankments and network rehabilitation can be declared economically feasible.