For many years Halcrow's largest overseas project was the Macagua No 1 hydropower scheme on the River Caroni, a tributary of the Orinoco in Venezuela.
The River Caroni has a high discharge rate and is therefore ideally suited for the generation of hydroelectric energy.
Built to supply power to an integrated iron and steel works the project involved a 375MW power station designed by Halcrow’s architectural department.
A concrete gravity dam, 30m high and 213m long, with central buttress sections was designed to take advantage of a natural step in the rock, so that the dam stands 40m above the power-station which forms an integral part of the dam. The dam is served by 6 water-intakes controlled by 11m wide taintor gates. In order to ensure the stability of the down-stream toe, it was necessary to pre-stress the rock on which the water-intake was housed.
The power house, placed at the base of the intake structure and made to extend to its full length, forms an integral part of the dam.
Completed in 1959, on schedule, the scheme cost £15 million.