Drought is causing water levels to drop in Lake Mead, where Las Vegas and surrounding areas get 90% of their water. There are two intakes in the Lake. One could go dry. That’s why this third intake, which will be at the bottom of the lake, is crucial for continued and steady water supplies to the area.
It’s one of the complicated and dangerous tunneling jobs ever, three miles long, drilling through sometimes fractured rock. They are halfway there now, proceeding at an inch or so a minute.