Miskar Maini, Mashuri
Jongkong reservoir creates a reservoir of water that is used for the purposes of raw water as fundamental media for improvement of drinking water production especially at dry season for the District of Koba. The advantage of being able to hold water in wet season and releasing it in dry season will be detained if the life storage of the reservoir can be utilized effectively, but sedimentation problem will decrease its volume which can influence the life time of reservoir. Finally the reservoir becomes less effective, so it is very important to study. The method which is used to predict an average erosion rate in the catchment area considers factors of rain erosivity, soil erodibility, ground inclination of slope or slope length, management of crop and land, soil conservation. Calculation was done by using the USLE equation (Universal Soil Loss Equation) which was developed by Wischmeier and Smith (1965, 1978). From this research result, the prediction of surface erosion rate in the basin catchment area in the year 2019 is equal to 53.20 mm/year or equivalent with 62,491.92 m3/year, and the value of Sediment Delivery Ratio (SDR) is equal to 32,28 %. The number of material which eroded is equal to 957.59 Ton/Ha/year so it is classified into the medium erosion class category. The dead storage of 5% of the the volume of the reservoir cage will be fully charged in the year 2022 or for 3 The next year and the total volume of the reservoir Ridge will be full of sediment in the year 2062 or 43 years. © 2020 Published under licence by IOP Publishing Ltd.
Civil Engineering Study Program, Faculty of Infrastructure and Regional Engineering, Institut Teknologi Sumatera, Indonesia