Mexican utility Comision Federal de Electricidad (CFE) plans to seek bids by the end of the year for construction of two diversion tunnels to bypass a mudslide that blocked the Grijalva River among the dams of the Grijalva hydroelectric system.
Crews managed to dig a canal through the November 2007 mudslide that allowed partial resumption of river operations. However, CFE said the tunnels are necessary due to the magnitude of the 20 million-cubic-meter slide and the continued instability of the land in the area.
The two 14-meter-diameter, 900-meter-long tunnels would cut through the neck of a horseshoe bend in the river, bypassing the mudslide in the river’s bend. The tunnels would carry flows of 2,150 cubic meters per second, which, added to the remaining flows through the mudslide canal, would allow total flows of 4,100 cms.
Mexican President Felipe Calderon Hinojosa authorized the project September 10. CFE said the project would ensure normal operation of the Grijalva River hydro projects, 1,080-MW Malpaso (also called Nezahualcoyotl), 420-MW Penitas (Angel Albino Corzo), 2,430-MW Chicoasen (Manuel Moreno Torres), and 900-MW La Angostura (Belisario Dominguez). (HNN 1/5/07)
CFE said it a solicitation for the tunnels’ construction would be carried out by the end of the year, with construction expected to require 18 to 24 months. CFE estimated the project would cost 600 million pesos (US$56.6 million).
For information, contact Comision Federal de Electricidad, Gerencia de Licitaciones y Contratacion de Proyectos, Subdireccion de Contratacion de Proyectos de Inversion Financiada, Paseo de la Reforma 164, Mezzanine 1, Colonia Juarez, Distrito Federal 06600 Mexico; Fax: (52) 5229-4755; E-mail: email@example.com; Internet: www.cfe.gob.mx.