Improper management of dams constructed with local materials, infiltration risk and wasted electric energy

Department of Hydraulics, Hydraulic machinery and Environmental Engineering, Faculty of Energy, University Politehnica of Bucharest, Splaiul Independentei 313, Sector 6, Bucharest, Romania

^* Corresponding author: vradul4@gmail.com

Abstract

The present paper presents a study case of improper dike rehabilitation and inefficient management of the water volume from two hydropower lakes, with dams built with local materials. In Romania, with its high hydrographic potential, this solution was adopted for construction of more than 600 hydropower plants, many of them now confronted with infiltration and erosion, and appeared into lateral sides of the dikes. The paper covers some theoretical and practical aspects referring to the functioning of hydropower lakes, establishing the cross-sections with problems in exploitation. Reduced water level produces less electric energy than initially estimated. The dam's construction was not correlated with the geomorphologic conditions and climatic parameters, being necessary supplementary measurements and data acquisition to calibrate the numerical model. There are mentioned some considerations referring at the mathematical model, based on new hypotheses of infiltration through sediments with different dimensions and characteristics. The flow through dikes is assumed non-permanent due to massive infiltration. Part of the numerical modeling, the obtained velocities of infiltration, and the streamlines are illustrated. The results of the tested solution prove its efficiency and allow illustrating and some other sections with possible risk in functioning. Some discussions, conclusions, and references are finally presented.