Estimation of diversion head loss at hydropower surface intakes

Many hydropower plants are designed with a surface intake that diverts water from a headpond, or reservoir, created on the river. The river diversion causes a head loss, defined as the difference in water level between the headpond and the intake. To estimate the diversion head loss, a 2D depth-averaged numerical model (River2D) was used to simulate the river and intake flow for a typical river intake layout and a range of flows and diversion angles. Based on the simulation results, an equation is proposed to estimate the diversion head loss as a function of the upstream river velocity, the intake velocity and the angle of diversion.