Las Vegas Drilled A New Straw Under Lake Mead #engineering #lasvegas

“Las Vegas drinks Lake Mead through pipes cut into rock. The problem with a pipe cut into rock is that its height never changes. Two intakes were built for a lake that behaved. For most of fifty years Lake Mead sat between 1,180 and 1,220 feet above sea level. Intake No. 1 stops working when the surface falls to about 1,050 feet. Intake No. 2 stops at about 1,000. Below the hole there is nothing left to draw, and no pump fixes that — running them harder cannot move an opening that was drilled at one elevation. By August 2006 the surface already read 1,127 feet, under the band it had held for half a century. Both straws were counting down. So the answer went under the lake instead of into it. A tunnel boring machine cut a bore roughly 20 feet across and about 18,000 feet long beneath the lake bed, lined with precast concrete segments, and the new intake opening was set at 860 feet — deliberately deep, below the thermocline, where the water stays coldest and cleanest. The US Geological Survey lists that bore as a monitoring site in Clark County, classified as a tunnel. Then in July 2022 Lake Mead fell to 1,040.92 feet, its record low — below the level where the first intake stops working. Sources: US National Park Service — Lake Mead Intake No. 3 Environmental Assessment US Bureau of Reclamation — Lake Mead at Hoover Dam, end of month elevation US Geological Survey — Lake Mead Intake No3 Connector Tunnel monitoring site AI notice: the visuals in this video are AI-generated. The engineering and the figures are not. Every number here comes from published federal material. #engineering #lasvegas #lakemead #water #desert #howitworks”