Friday, Sept. 11, 2015 | 4:20 p.m.
A careful flooding operation has begun on a so-called "Third Straw" pipeline to draw Las Vegas drinking water from near the bottom of drought-stricken Lake Mead.
Southern Nevada Water Authority spokesman Bronson Mack said Friday that contractors began this week to allow in the first 11 million gallons of the 41 million gallons need to flood the 3-mile tunnel.
The process is expected to take several weeks before a cap is removed and the Colorado River reservoir will directly flow to pumping stations.
The third intake cost some $817 million to build.
It's designed to ensure that Las Vegas can still get water if the lake surface drops below two existing intakes.
Las Vegas gets about 90 percent of its drinking water from the reservoir behind Hoover Dam.
