a group of hydroelectric power plants located in series along a watercourse and interconnected to form a common water-use system. The construction of a hydroelectric system makes possible more complete use of the energy resources of a river, increases discharge control (which results in increased power and capacity of the hydroelectric plants), and improves the power switching capabilities of individual plants. It is also the most promising course for reconstruction of river transportation.
On the Volga and Kama rivers the construction of hydroelec-tric systems led to the creation of a waterway with a standardguaranteed depth of 3.65 m for a distance of 3, 000 km along theVolga and 1, 200 km along the Kama; the Volga-Kama andDnieper hydroelectric systems are the basis of a standard deep-water transportation system that will link the ports of the Cas-pian, Black, Baltic, and White seas and the Sea of Azov. Thelargest systems in the USSR are the Enisei Hydroelectric System(eight plants), the Angara Hydroelectric System (six plants), theVolga Hydroelectric System (eight plants), the Dnieper Hydro-electric System (six plants), and the Kama Hydroelectric System(four plants).