El Cajon Dam on the Humuya river

Name of Project:
El Cajon Dam on the Humuya river


Country:
Honduras

Client:
Empresa Nacional de Energía Eléctrica (ENEE)

Construction period:
April 1980 - June 1985

The El Cajón hydroelectric plant is located on the Humuya river, in central Honduras. Its fundamental purpose is to produce electric energy, but the structure also controls flood waters and ensures regular irrigation during the year.
The double-curvature concrete arch dam has a maximum height of 226 m, a crest length of 382 m and thickness varying between 48 m at the base and 7 m at the crest, where, at an elevation of 301 m above sea level, an ungated four-tube spillway has been built. Three bottom outlets with a diameter of 4.8 m diameter have been built at an elevation of 170 m.
The spillway consists of a concrete pressure tunnel with an internal diameter of 12 m and a length of 290 m.
The diversion works consist of a 13 m diameter and 500 m long concrete tunnel and of two rockfill cofferdams. 
Excavation of about 13 km of inspection, drainage and grouting galleries with a 10 m² cross-section, includes the construction of an impermeabilisation system which required 535,000 m of drilling and more than 95,000 tonnes of cement grouting.

MAIN TECHNICAL DATA:
Open-cut excavation: 1,950,000 m3  
Underground excavation: 280,000 m3
Dam concrete: 1,480,000 m3  
Other concrete: 145,000 m3 
Cofferdams: 270,000 m3

Last update: 25/09/2014