Flow Velocity and Sediment Transport Analysis at Intake of Asahan I Hydroelectric Power Plant

Abstract

Asahan I Hydroelectric Power Plant is located in the upper reaches of the Asahan River, Ambarhalim Village, Toba Samosir Regency, North Sumatra. The high rate of sedimentation is one of the problems that must be overcome so that the operational continuity of hydroelectric power plant can run well. Flow velocity needs to be known to control sedimentation around hydroelectric power plant intakes as a consideration for the safe limit of dredger placement. The method used to analyze flow velocity included conventional flow continuity methods and finite element mathematical models using the SRH-2D software. The results of the conventional method analysis of flood conditions Flood Water Level = +903.50 m obtained the flow velocity at the intake of 0.34 m/s, the transition channel 0.37 m/s and the condition of full capacity Q = 100.00 m3/s is 3.78 m/s and analysis using SRH-2D obtained speed flow <4 m/s. Both of these conditions make it possible to carry out sediment dredging in the hydroelectric power plant intake.