Rebecca Maloney
Americas Press Office ,Boston
Arup, along with our collaborators Salini-Impregilo and S.A. Healy, was awarded Global Tunnelling Project of the Year at the 2015 NCE Tunnelling and Underground Space Awards.
We led the engineering design of the vital new intake tunnel for Lake Mead, the largest man-made reservoir in the United States, which provides water to Las Vegas residents. The deepest sub-aqueous tunnel in the world, the 4.6km-long, 6.8m-diameter tunnel boring machine tunnel at intake No. 3 will safeguard future water quality and supply amid declining lake levels and ensure that Lake Mead can provide water in case of severe drought.
Lake Mead covers 247mi2 and has a depth of 532ft at full capacity. Before the tunnel at intake No. 3 was completed, the lake had two intake shafts. These shafts risked becoming inoperable as the lake’s water level continued to drop, potentially shutting off water supply from the lake to Las Vegas residents.
Arup provided structural, geotechnical, highway, maritime, and water engineering, as well as site supervision services and tunnel design. The tunnel passes through extremely challenging ground and groundwater conditions and required the expertise of Arup's materials and hydraulics specialists to design the project’s deep water lake intake.
“The integrated design of this significant and technically advanced assignment involved a team of global Arup engineers, and called on the firm’s expertise in tunnelling, geotechnics, hydraulics, site development and offshore design. The technical complexity and sheer risk to human health and viability make this project one of the most critical undertakings in the United States at the moment.
Don Phillips, Arup principal and design manager for the project.