The project involved the construction of a system for collecting and transporting the waters of Lake Mead, located approximately 30 kilometres south-east of the city of Las Vegas (Nevada), in order to increase the supply of water, approximately 4.5 million cubic metres per day, for drinking and domestic use in the urban area of Las Vegas.
Lake Mead is the largest man-made lake in the United States and is formed from the Hoover Dam, which blocks the path of the Colorado River, a few kilometres from Las Vegas.
The works involved the construction of an access shaft, excavated in the rock on the shore of the lake, approximately 200 m deep and with a diameter of 9 m. A tunnel was constructed at the bottom of the shaft under the lake bed approximately 4,600 m long and with an excavation diameter of 7.2 m. The intake work is located at the end of the tunnel, approximately 100 metres below the surface of the lake, made from a pipe-shaped tubular steel structure with a diameter of 6 m and a height of approximately 30 m.
The water, drawn in from the bottom of the lake through the intake work openings, is directed along the tunnel to the access shaft, from where it is pumped to the treatment plant on the surface.
Awards. In September 2016 Tunnel Business Magazine (TBM), one of the industry’s leading magazines, assigned to the project the “Tunneling Achievement award of the year”. In November 2015 the Lake Mead Tunnel was nominated “Project of the Year” by the International Tunnelling Association in Switzerland, and, in December 2015, was awarded the “Project of the Year” prize by the New Civil Engineer (NCE), a prestigious organization of the British Tunneling Society. The project also won the (Engineering Excellence Award) of the American Society of Civil Engineers (ASCE) for the State of Nevada.
|MAIN TECHNICAL DATA:|
|Tunnel excavation: 195,000 m³|
|Shaft excavation: 4,500 m³|
|Underwater excavation: 30,000 m³|
|Structural Concrete: 10,935 m³|
Lake Mead intake hydraulic tunnel, Las Vegas