WorldWide Drilling Resource

Lake Mead Intake Among World’s Best Projects Adapted from Information Provided by Southern Nevada Water Authority The recently completed drinking water intake constructed to protect Southern Nevada residents from continuing drought was nominated for the 2016 Outstanding Civil Engineering Achievement Award by the prestigious American Society of Civil Engineers (ASCE). Listed among six projects selected from around the world, Lake Mead Intake No. 3 is the world’s deepest subaqueous tunnel and is considered one of the most challenging tunneling projects ever undertaken. Requiring construction of a three-mile concrete-lined tunnel beneath the lakebed, the project demanded excavation at unprecedented hydro- static pressure caused by the weight of hundreds of feet of lake water above the tunnel alignment. As a 1700-ton tunnel boring machine (TBM) inched its way through difficult geologic conditions for several years, workers constructed a railroad track in its wake to remove material and deliver supplies. In December 2014, the machine docked with an intake structure deep within the lake, secured to the bottom by over 1000 truckloads of concrete. After more than 15,000 feet of underground tunneling spanning three years, the crew carefully mined through the intake’s port within millimeters of the center mark. “Together with the designer and builder of the intake project, we are honored to be considered for this award, which represents the pinnacle of modern civil engineering achievement,” said Marcus Jensen, Director of Engineering for the Southern Nevada Water Authority (SNWA). “Lake Mead Intake No. 3 has been the most ambitious project ever undertaken by the SNWA. During the course of the project, our team focus was singularly on the task at hand. However, once the work was done, we had the opportunity to step back and consider the challenges we overcame and the magnitude of what we accomplished. It is quite humbling.” Editor’s Note: In between our print issues, the WWDR Team prepares an electronic newsletter called E N s h - ew Flas . Based on readership, this was the most popular - ew a E N s Fl sh article of the month. A previous article about Lake Mead’s Intake No. 3 was the E N s h - ew Flas Readers’ Choice in the March 2015 issue. For additional information a bout the project, visi t worldwidedrillingresource.info/archiv/2015/March15/index.html?pageNumber=74 Get in on the action and subscribe today at: www.worldwidedrillingresource.com Photo taken onboard the 600-foot-long gentry that trailed behind the TBM. Train tracks down the middle were used to convey materials and supplies to and from the TBM using a small train. 48 APRIL 2016 WorldWide Drilling Resource ®