Excess Water Slows Lake Mead Connector Tunnel

A local news report said completion of a half-mile connector tunnel will come in January and cost $5 million more than a previous estimate because more water is seeping into the work site than expected.

The Southern Nevada Water Authority’s drinking water Intake No. 3 project has been slowed a bit, according to a report published by the Las Vegas Review-Journal. The newspaper reported the authority’s board voted May 17 to approve a $5 million change order that means a half-mile connector tunnel won’t be finished until January 2013.

The reason is that more water is seeping into the work site around 400 feet underground than expected, according to the report, which said the $800 million project already has fallen about 20 months behind schedule.

The project initially won approval in May 2005 in response to unprecedented drought conditions. It is intended to protect southern Nevada's primary water source, Lake Mead, and when completed will allow the authority to draw upon Colorado River water at lake elevations as low as 1,000 feet above sea level (ensuring system capacity if lake levels fell low enough to put Intake No. 1 out of service). Intake No. 3 will connect existing Intake No. 2 to carry water to the authority’s water treatment facilities.

In March 2012, the concrete pour for the structure of Intake No. 3 was completed 2.5 miles off the shore of Lake Mead over a period of 12 days. The work required 12,000 cubic yards of concrete pumped from 1,086 trucks that were carried to the site on 143 barges.