Location of dam and HPP
“Drina I” dam and HPP are planned on the Drina River, at the chainage km 43+600, in the vicinity of the Kozjak settlement. The location belongs to the municipality of Kozjak; the nearest town is Loznica.
Profile hydrological properties from original documentation
Basic profile hydrological properties (as given in the original technical documentation) are:
- Mean discharge: 372.5 m3/s (for “Zvornik” profile) and
- Ecological flow: 71 m3/s (for “Zvornik” profile, minimum monthly discharge with 95% availability).
Basic dam properties are:
- Type: gravity, concrete,
- Crest elevation: 123.5 m.a.s.l.,
- Height: 29.0 m (construction height),
- Length along the crest: 183.4 m, (approximate),
- Storage evacuation structures: gated spillways, 4 fields each, additional 4 fields that also serve as bottom outlets and
- Total evacuation capacity: 4,075 m3/s.
Basic storage properties are:
- Regular water level: 121 m.a.s.l.,
- Maximum water level: 121 m.a.s.l.,
- Total volume: 85 million m3,
- Storage length: 16.6 km and
- Surface area: 14.2 km2.
The plant belongs to the non-diversion type.
Basic HPP/powerhouse properties are:
- Plant type: non-diversion,
- Unit type: bulb with horizontal shaft,
- Number of units: 4,
- Installed discharge: 800 m3/s,
- Tailrace water level: 108.0 m,
- Gross head: 13.0 m (operating head),
- Head loss: 0.2 m,
- Net head: 12.8 m,
- Installed power: 87.7 MW and
- Mean annual electricity generation: 363.7 GWh
The present “Zvornik” HPP installed discharge amounts to 600 m3/s, but it is planned to be increased to 800 m3/s, in order to align this part of the HPP cascade regarding discharges. The installed discharge of the “Bajina Bašta” HPP can be modified during the rehabilitation process and the installation of the fifth unit.
(Source: IWRM Country Report for Serbia, COWI, Stucky and Jaroslav Cerni Water Institute, 2017)