Valeira Dam (Portuguese: Barragem da Valeira) is a concrete gravity dam on the Douro, where the river forms the border line between the districts of Viseu and Bragança. It is located in the municipality São João da Pesqueira, in Viseu District, Portugal.

Valeira Dam
Valeira Dam downstream of the curve that follows the exceptionally tight gorge of the Douro River, known as Cachão da Valeira
Valeira Dam is located in Portugal
Valeira Dam
Location of Valeira Dam in Portugal
Official nameBarragem da Valeira
CountryPortugal
Locationmunicipality São João da Pesqueira, Viseu District
Coordinates41°9′37.8″N 7°22′27.1″W / 41.160500°N 7.374194°W / 41.160500; -7.374194
PurposePower
StatusOperational
Construction began1971
Opening date1975
Owner(s)Companhia Portuguesa de Produção de Electricidade
Operator(s)Energias de Portugal
Dam and spillways
Type of damConcrete gravity dam
ImpoundsDouro
Height (foundation)48 m (157 ft)
Length380 m (1,250 ft)
Elevation at crest113 m (371 ft)
Width (crest)6 m (20 ft)
Dam volume220,000 m3 (7,800,000 cu ft)
Spillway typeDam body
Spillway capacity18,000 m3/s (640,000 cu ft/s)
Reservoir
Total capacity97,000,000 m3 (79,000 acre⋅ft)
Active capacity8,000,000 m3 (6,500 acre⋅ft)
Surface area7.95 km2 (3.07 sq mi)
Normal elevation105 m (344 ft)
Operator(s)Energias de Portugal
Commission date1976
Hydraulic head31.5 m (103 ft) (max)
Turbines3 x 82.4 MW Kaplan-type
Installed capacity240 MW
Annual generation610.7 GWh

Construction of the dam began in 1971. The dam was completed in 1975. It is owned by Companhia Portuguesa de Produção de Electricidade (CPPE).[1]

Valeira Dam is a 48 m tall (height above foundation) and 380 m long gravity dam with a crest altitude of 113 m. The volume of the dam is 220,000 m3. The spillway with 5 radial gates is part of the dam body (maximum discharge 18,000 m3/s).[1]

Reservoir

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At full reservoir level of 105 m the reservoir of the dam has a surface area of 7.95 km2 and a total capacity of 97 mio. m³.[1] The active capacity is 8[1] (12,[2] 13[3] or 13,04[4]) mio. m³.

Power plant

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Valeira Dam

The run-of-the-river hydroelectric power plant was commissioned in 1976[2][3][4] (1975).[5] It is operated by EDP. The plant has a nameplate capacity of 240[3][4] (216)[1][2][5] MW. Its average annual generation is 610.7[4] (663,[3] 748[2] or 801[1][5]) GWh.

The power station contains 3 Kaplan turbine-generators with 82.4 (72)[5] MW (80 MVA) each in a dam powerhouse located on the right side of the dam. The turbine rotation is 115.4 rpm. The minimum hydraulic head is 15.5 m, the maximum 31.5 m. Maximum flow per turbine is 360 m3/s.[4]

The turbines were provided by Kværner, the generators by Brown, Boveri & Cie.[5]

Lock

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On the left side of the dam is a lock, which can handle ships with the following maximum properties: 83 m in length, 11.40 m on the beam, 3.8 m load-draught and a cargo capacity of 2500 tons.[6]

See also

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References

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  1. ^ a b c d e f "VALEIRA DAM". APA Barragens de Portugal. Retrieved 2015-03-06.
  2. ^ a b c d "Hidroelectricidade em Portugal memória e desafio" (PDF) (in Portuguese). Rede Eléctrica Nacional, S.A. p. 29 (27). Archived from the original (PDF) on 2021-06-27. Retrieved 2015-03-02.
  3. ^ a b c d "DECLARAÇÃO AMBIENTAL 2012" (PDF) (in Portuguese). Energias de Portugal. pp. 41 (39). Archived from the original (PDF) on 2014-11-03. Retrieved 2015-03-02.
  4. ^ a b c d e "Valeira Informação Técnica" (in Portuguese). Energias de Portugal. Archived from the original on 2017-08-11. Retrieved 2015-03-06.
  5. ^ a b c d e "Valeira Hydroelectric Power Plant Portugal". Global Energy Observatory. Retrieved 2015-03-06.
  6. ^ "waterway introduction". Instituto Portuário e dos Transportes Marítimos. Retrieved 2015-02-11.