Tunnel machine digging again at Lake Mead

The Southern Nevada Water Authority's massive tunnel boring machine is chewing rock again at a work site 600 feet beneath Lake Mead.

The 1,500-ton digger began tunneling again on the authority's new water intake late Wednesday morning, 16 days after 44-year-old Thomas Albert Turner was killed at the site.

Turner was helping to assemble a ring of concrete pipe near the back of the tunnel boring machine when one of the ring sections slipped, releasing a stream of pressurized grout, mud and rock that hit the married father of two in the head.

It was the first accidental death at the construction site.

Work on the project was halted until Tuesday afternoon, when the Nevada Occupational Safety and Health Administration signed off on a corrective action plan by general contractor Vegas Tunnel Constructors.

State safety regulators are still investigating Turner's death.

Water authority spokesman J.C. Davis said the tunnel boring machine advanced about 30 feet in its first day of operation.

All told, the $25 million machine has excavated about 1,000 feet of a 23-foot-tall tunnel that will extend through three miles of solid rock to tap into the bottom of Lake Mead.

When finished, the $800 million third intake should keep water flowing to Las Vegas even if the reservoir shrinks low enough to shut down one of the two existing straws. Those pipes supply the valley with about 90 percent of its drinking water.

The project is running about 20 months behind schedule and is slated for completion in the summer of 2014.

Contact reporter Henry Brean at hbrean@reviewjournal.com or 702-383-0350.