Ready to go on San Francisco1 July 2004
Tunnelling works have now begun on the US$302M San Francisco Hydroelectric Power Project, in Ecuador. The 212MW scheme, which is located near the town of Banos on the Pastaza River, approximately 150km northeast of the capital Quito, involves the excavation of an 11.3km long, 7m diameter, headrace tunnel that will utilise both drill and blast and TBM techniques.
In addition, the US$286M EPC contract for underground works includes a 200m deep, 7m diameter vertical penstock, a 76m long x 20m wide x 45m high underground powerhouse and associated structures, discharge tunnel and construction adits.
The Hidropastaza consortium, consisting of Hidro Agoyan SA (who owns and operates the adjacent Agoy‡n Hydroelectric Power Plant) and Construtora Norberto Odebrecht SA, is currently drilling and blasting a 451m long powerhouse access tunnel, using a Tamrock jumbo, and a 600m adit, which will provide access to the headrace tunnel.
Once access has been gained to the headrace, excavation will commence using a 7m diameter double-shielded Wirth TBM. The TBM is currently being mobilised, with launch scheduled for January 2005.
The geology along the route of the headrace consists of metamorphic rocks including schist and gneiss, with the remaining drill and blast structures located in granite.
Based on a 30 year concession granted by the Ecuadorian Electricity Council, the project is being financed with a US$243M loan from the Brazilian development bank, Banco Nacional de Desenvolvimento Economico e Social, and equity contributions of US$59M from HidropastazaÕs shareholders. Power and energy from the project will be sold in the Ecuadorian Wholesale Market.
Construction is scheduled for completion in February 2008, with commercial operation of the first generating unit expected to take place in November 2007.
Plan map showing the TBM and drill & blast works