Estimation of Water Seepage from Upper Reservoir of Rudbar Pumped Storage Power Plant

One of the major problems during the construction and operation of reservoirs, which can undermine the water maintainability, is related to water seepage from the reservoir. In pumped storage power plant, due to connect between upper and main reservoir, water seepage from upper reservoir have a significant effect on the efficiency of the power plants to produce energy. The objective of this research is to estimate water seepage from the upper reservoir of Rudbar pumped storage power plant, based on combined geological and geotechnical investigations using numerical and analytical methods. Geological investigations show that the upper reservoir consists of limestone and marly limestone. Obtained data of seven exploratory boreholes and seven joint measurement stations have been considered as the main source for seepage calculations in analytical method and distinct element method (DEM), respectively. The input data such as permeability of layers and the hydraulical and mechanical properties of discontinuities has been obtained from measured data. Results from both methods (analytical and numerical) have an appropriate consistency together. The estimated seepage from analytical method and DEM is around 348,000 m³/day and 280,000 m³/day, respectively. Due to the high amount of water seepage and economical value of Water in this region, water tightening is necessary.