The Drina River is right and the largest tributary of the Sava River and belongs to the Black Sea Basin. It is formed by merging of the rivers of Tara and Piva, near Šćepan Polje. The catchment area encompasses the southwestern and western parts of the Republic of Serbia, the northern part of the Republic of Montenegro and the eastern part of the Republic of Srpska, and occupies an area of 19 570 km2 . The total length of the basin is about 500 km, and the average width is about 100 km. The annual precipitation in the upper part of the basin is 3000 mm, while an average precipitation at the entire basin is 1 100 mm.
HPP Foča is one of planned hydro power plants in the hydropower system of Upper Drina.
Basic technical data of HPP Foča
HPP Foča is an adjacent-to-the-dam, storage-type facility consisting of:
– a concrete, gravity-type dam with the spillways,
– powerhouse
– reservoir.
Installed capacity N = 44.15 MW
Generation E = 175.87 GWh
Installed flow Qi= 350 m3/s
The concrete, gravity-type dam with an overflowing and a non-overflowing part is adopted.
The crest elevation is 406.80 m a.s.l. The length of the dam at the crest is 208.4 m, while the crest width range from 9.7 m to 13.1 m. The length of the left gravity section is 58 m, while the powerhouse takes 43.4 m, a part of the dam with spillways 74 m and a right gravity part 33 m. The highest construction height is at the part of the powerhouse and it is 43.4 m.
The normal pool elevation is 403 m a.s.l. and total storage capacity is 6.70 x 106 m3. The active capacity is 4 x 106 m3. The operation level starts at 403 – 396 m a.s.l.
Three generating sets are located in the powerhouse. The tubular turbines are used.
The flow rate for two sets will be 150 m3/sec, while the third set shall have the minimum flow rate of 50 m3/sec.
