Rehabilitation of Drenska Dam with machine excavation on land with an appropriate scraping of the terrain, embankment of separated earth material, installation of waterproof HDPE geomembrane between two layers of geotextile. Construction of overflow body, construction of foundation outlet/drain pipe, earth pit and drainage in the riverbed, construction of a gate chamber along with hydromechanical equipment as well as installation of benchmarks and geodetic points and piezometric constructions for auscultation of the dam during exploitation.