The Caruachi Dam is a concrete gravity dam on the Caroní River in Bolivar state, Venezuela. It supports a hydroelectric power facility with a 2160 MW capacity. It is about 59 km downstream from the Guri Dam belonging to the Central Hidroeléctrica Simón Bolívar, and about 35 km from where the Caroni and Orinoco rivers meet at Ciudad Guayana.

The dam

The first of the 180 MW Kaplan turbine-generators General Electric supplied for the project began commercial operation in April 2003; the 12th and final unit entered service on February 28, 2006, and entered into formal/fully commercial operation on 31 March 2006, when the project was officially inaugurated. The total installed capacity is 2,160 MW and the power plant will produce about 12 TW·h annually. This project is formed jointly with the Central Hidroeléctrica Simón Bolívar in Guri, Antonio José de Sucre in Macagua and Manuel Piar in Tocoma (under construction), the development of Lower Caroní River hydroelectric resources and one of the world's largest hydro projects now in construction, that, when completed, EDELCA (Electrificación del Caroní CA) claims will save Venezuela the equivalent of 750,000 barrels of oil per day, compared to 300,000 currently.

Design and construction

The contract for the design, supply and installation of the main electro-mechanical equipment was awarded to a consortium of Kvaerner of Norway, GE Energy of the US, and Elin Transformatoren GmbH of Austria. Major work began on the project in 1998. Following GE's acquisition of Kvaerner's hydro business in 1999, over 90% of the Caruachi contract was carried out by GE Hydro, including all aspects of the design, supply and installation of the turbines, generators, governors, exciters and cranes. A total of 12 Kaplan turbine-generator units, each capable of a power output of 180 MW, were supplied to the project. ABB of Switzerland won three contracts to provide the power transmission system for the project. A 400 kV substation and four related 400 kV transmission lines connect the plant with the country's transmission network. Alstom Power was awarded the contract for distributed control system and SCADA, and small electrical auxiliaries like UPS equipments and DC distribution boards. The original GE Hydro and Elin contracts were, through several mergers and acquisitions, transferred to the 2005-created Andritz Hydro of Austria. While the original Alstom contract was in 2014 inherited by a new GE Renewable Energy entity.

Features

A main concrete 360 m gravity dam has a maximum height of 55 m from its foundations, with an integrated intake structure and powerhouse. A 900 m right-abutment rockfill closure dam has a concrete slab face and a maximum height of 50 m, and a 4,200 m left-abutment earth and rockfill closure dam has a maximum height of 45 m. A spillway with nine spans and radial surface gates has an aggregate 30,000 m3/s flow capacity. A 470 m powerhouse is integrated with the main dam with space for 12 generating units (360 m) and an assembly bay of 110 m. Two transition dams have a 50 m intermediate buttress between the powerhouse and spillway. The 238 km2 reservoir has a normal operating elevation of 91.5 m above sea level.