Location of dam and HPP “Buk Bijela” dam and HPP are planned at the Drina River, at the chainage km 334+550, approximately 11.6 km upstream of the city of Foca and at approximately 11.5 km downstream of the mouth of Piva River and Tara River at Scepan Polje (border between Montenegro and BIH (Republic of Srpska)). The location belongs to the municipality of Mjesaji and the nearest town is Foca.
Profile hydrological properties
Basic profile hydrological properties (as given in the original technical documentation) are:
- Basin surface area: 4,158.3 km2,
- Mean discharge: 162.37 m3/s,
- Ecological flow: 24.4 m3/s (minimum mean monthly discharge with 95% availability),
- Flood discharge referent for design of spillways: 3,790 m3/s (Q0.1, one gate closed).
“Buk Bijela” dam height was chosen based upon the condition that the storage should not disturb the natural flow regime at the “Šćepan Polje” profile under the conditions of the mean multi-annual Tara River discharge (70 m3/s) and under the conditions of the “Piva” HPP installed discharge (240 m3/s).
Basic dam properties are:
- Dam type: concrete, gravity dam,
- Dam height: 36 m (maximum construction height 57.80 m),
- Total length along the crown: 197.3 m,
- Maximum dam width at the crown: 15.5 m,
- Storage evacuation structures: two gated spillways and one bottom outlet and
- Total evacuation capacity:3,790 m3/s.
Basic storage properties are:
- Regular water level: 434.0 m.a.s.l.,
- Maximum water level: 434.0 m.a.s.l.,
- Minimum operating water level: 420.5 m.a.s.l.,
- Total volume: 15.7 million m3,
- Active volume: 11 million m3,
- Inactive volume: 4.7 million m3,
- Ratio between active volume and mean annual inflow: 0.002,
- Total length: 11.5 km,
- Greatest width: approximately 135 m,
- Surface area: 123.3 ha and
- Highest depth: approximately 34 m.
The plant belongs to the non-diversion type.
Basic HPP/powerhouse properties are:
- Plant type: non-diversion,
- Unit type: Kaplan with vertical shaft,
- Number of units: 2 +1,
- Installed discharge: 2 x 150 + 50 = 350 m3/s,
- Tailrace water level: 403 m.a.s.l.,
- Gross head: 31.0 m,
- Rated net head: 29 m,
- Installed power (active): 2 x 40.1 + 13.3 = 93.5 MW,
- Installed power (apparent): 2 x 45 + 15 = 105 MVA,
- Mean annual electricity generation: 332.34 GWh and
- Connection voltage: 110 kV, 400 kV.
Source: IWRM Country Report for B&H, COWI, Stucky and Jaroslav Cerni Water Institute, 2017