Using HEC-RAS Program to Predict the Effect of Water Level Changes in Kiwal Retention Pond of Buah River

Abstract

The Based on the division of river areas in the city of Palembang, there are 21 sub-watersheds, but only 18 sub-watersheds that lead directly to the Musi river, namely the Rengas Lacak, Gandus, Lambidaro, Boang, Sekanak, Bendung, Lawang Kidul, Buah, Juaro, Batang sub-watersheds, Keramasan, Kertapati, Kedukan Ulu, Aur, Sriguna, Jakabaring and Plaju. The area of Palembang city which always experiences floods every year, among others, is the watershed area of the Buah River. The Buah River, with the main river being 7.93 km long, has many meanders and a river wall reinforcement has been built. The research was conducted to see changes in the water level in the Buah river using the HEC-RAS ver.4.1.0 program.The results showed the pattern of water level movement at each station in the cross section of the river under study, where at Sta. 6+860.5 and Sta. 6+850 there is no rise in the water level in the Sungai Buah. This condition is due to the influence of the Kiwal retention pond to lower the water level in the Buah river. But at Sta. 6 + 800 to Sta. 6+450 there is a water level fluctuation with a significant increase in the river, after which there is a decrease in the water level in the river, namely at Sta. 6+400 up to Sta. 6+350. This is a condition where the river does not affect the Kiwal retention pond