Mequinenza Dam
Location of Mequinenza Dam in Spain
Official name	Presa de Mequinenza
Location	Province of Zaragoza, Spain
Coordinates	41°22′08″N 0°16′24″E / 41.368983°N 0.273381°E / 41.368983; 0.273381
Purpose	Power
Status	Operational
Construction began	1957
Opening date	1964
Owner(s)	Endesa
Operator(s)	Endesa
Dam and spillways
Type of dam	Concrete gravity dam
Impounds	Ebro
Height (foundation)	79 m (259 ft)
Length	461 m (1,512 ft)
Elevation at crest	124 m (407 ft)
Dam volume	1,100,000 m3 (39,000,000 cu ft)
Spillway type	Over the dam
Spillway capacity	11,000 m3/s (8.9 acre⋅ft/s)
Reservoir
Total capacity	1,530,000,000 m3 (1,240,000 acre⋅ft)
Surface area	75.4 km2 (29.1 sq mi)
Maximum length	110 km (68 mi)
Maximum width	600 m (2,000 ft)
Maximum water depth	62 m (203 ft)
Normal elevation	121 m (397 ft)
Commission date	1966
Turbines	4 x 96 MW Francis-type
Installed capacity	384 MW

Mequinenza Dam (Spanish: Presa de Mequinenza) is a concrete gravity dam in the province of Zaragoza, Spain. It impounds the Ebro creating a large reservoir, which is called Mar de Aragón.^[1] About 35 km downstream of Mequinenza dam is Ribarroja dam.

Empresa Nacional Hidroeléctrica del Ribagorzana S.A. (ENHER) was mandated in 1955^[2][3] by Instituto Nacional de Industria (INI) to build two dams on the Ebro near Mequinenza and Ribarroja. Work on Mequinenza dam started in 1957.^[1] The filling of the reservoir began in December 1965.^[2] The power plant was operational in 1964^[3][4] (1966^[5]). ENHER was acquired by Endesa in 1999.^[6]

Mequinenza Dam is a 79 m tall (height above foundation) and 461 m long gravity dam with a crest altitude of 124 m. The volume of the dam is 1,100,000 m³. The dam features a spillway with 6 gates over the dam (maximum discharge 11,000 m³/s) and one bottom outlet (maximum discharge 160 m³/s).^[7]

At full reservoir level of 121 m.a.s.l. the reservoir has a surface area of 75.4 km², a total capacity of 1.53 billion m³ and a length of almost 110^[2][3] km. The average width of the reservoir is about 600 m, its maximum (average) depth is 62 (20) m.^[5]

The power plant contains 4 Francis turbine-generators. The initial nameplate capacity was 81 MW each. The turbines, generators and transformers were refurbished from 2007 until 2010 raising the capacity of the new machines to 96 MW each.^[4] Maximum flow is 150 m³/s per turbine.^[5]

• List of power stations in Spain
• List of dams and reservoirs in Spain

Wikimedia Commons has media related to Mequinenza Dam.

• "La presa de Mequinenza". Wikimapia. Retrieved 2016-04-23.
• "Embalse de Mequinenza". megaconstrucciones.net. Retrieved 2016-04-23.