Fratel Dam Explained

Fratel Dam
Name Official:Barragem de Fratel
Location Map:Portugal
Coordinates:39.5428°N -7.8029°W
Location:municipality Fratel, Vila Velha de Ródão, Portugal
Purpose:Power
Status:O
Opening:1973
Owner:Companhia Portuguesa de Produção de Electricidade
Operator:Energias de Portugal
Dam Type:Concrete gravity dam
Dam Crosses:Tagus
Dam Height Foundation:48m (157feet)
Dam Height Thalweg:43m (141feet)
Dam Length:240m (790feet)
Dam Elevation Crest:87m (285feet)
Dam Volume:124000m2
Spillway Type:Dam body
Spillway Capacity:16500m2
Res Capacity Total:92500000m2
Res Capacity Active:21000000m2
Res Surface:10km2
Res Elevation:74m (243feet)
Plant Operator:Energias de Portugal
Plant Commission:1974
Plant Hydraulic Head:28.8m (94.5feet) (max)
Plant Turbines:3 x 45.6 MW Kaplan-type
Plant Capacity:132 MW
Plant Annual Gen:357.9 GWh

Fratel Dam (Portuguese: Barragem de Fratel|links=no) is a concrete gravity dam on the Tagus, where the river forms the border line between the districts of Castelo Branco and Portalegre. It is located in the municipality Vila Velha de Ródão, in Castelo Branco District, Portugal.

The dam was completed in 1973. It is owned by Companhia Portuguesa de Produção de Electricidade (CPPE). The construction of the dam meant the flooding of most of the tens of thousands of petroglyphs found in the Tagus valley rock art area.[1]

Dam

Fratel Dam is a 48 m tall (height above foundation) and 240 m long gravity dam with a crest altitude of 87 m. The volume of the dam is 124,000 m³. The spillway is part of the dam body (6 radial gates with a maximum discharge capacity of 16,500 m³/s).

Reservoir

At full reservoir level of 74 m (maximum flood level of 76 m) the reservoir of the dam has a surface area of 10 (7,3) km² and its total capacity is 92.5 mio. m³. The active capacity is 21 mio. m³. Minimum operating level is 71 m.

Power plant

The run-of-the-river hydroelectric power plant went operational in 1974. It is owned by CPPE, but operated by EDP. The plant has a nameplate capacity of 132 (130) MW. Its average annual generation is 357,9 (327, 347.5 or 382) GWh.

The power station contains 3 Kaplan turbine-generators with 45.6 MW (50 MVA) each in a dam powerhouse. The turbine rotation is 150 rpm. The minimum hydraulic head is 17.8 m, the maximum 28.8 m. Maximum flow per turbine is 250 m³/s.

See also

Notes and References

  1. Arcá. Andrea. 2001. Damned dams again: the plight of Portuguese rock art. Rock Art Research. 18.