Thursday, October 21, 2004
Copyright © Las Vegas Review-Journal

HOOVER DAM BYPASS: Dam bridge moves closer

Nevada, Arizona dignitaries gather to mark progress

Michael Kondelis, an Arizona Department of Transportation engineer, stands near the Arizona starting point for the Hoover Dam bypass bridge on Wednesday. Work is scheduled to begin on the bridge before the end of the year. Photo by John Locher. Click image for enlargement. Graphic by Mike Johnson.

With financial and preparatory hurdles largely in the past, builders of the Hoover Dam bypass bridge are now focusing on a pair of more fundamental foes: rock and wind.

Topography and weather will challenge crews as the 1,905-foot span over the Colorado River just downstream of the dam begins to take shape by the end of this year.

"This is a tough job," Dave Zanetell, the Federal Highway Administration's bypass project manager, said prior to a bridge work celebration Wednesday attended by Gov. Kenny Guinn, U.S. Sen. Harry Reid and other dignitaries.

"It fulfills so many needs for our region, our states and our country," said Arizona Gov. Janet Napolitano, one of the attendees. "Economically, for our region, it's huge."

Work on the $234 million bypass and four-lane bridge is on-budget and in line to be finished in 2008.

When complete, the bypass will carry U.S. Highway 93 traffic now crossing the river atop the dam and become part of the planned CANAMEX trade corridor, linking Mexico, the western United States and Canada via one highway.

The bridge's Arizona approach is almost finished, and the Nevada approach is half-done.

"The only thing missing is that big bridge," Zanetell said. "That's what we are going to get started on."

The bridge, which will rise almost 900 feet above the river about a quarter-mile south of the dam, will be the longest concrete arch in the United States.

Building it will be tricky. "The big challenge is the wind," said Zanetell, adding that gusts of 30 mph or more are not uncommon in the area.

"The bottom line is we expect for there to be 20 percent of days where the wind conditions will be such that they'll be unable to work," Zanetell said.

When constructed, the bridge should be able to withstand winds of up to 100 mph, Zanetell said.

The bridge's supports will be built into solid rock. "Truly, it's the good news and the bad news," Zanetell said.

That's because rock provides a wonderfully stable base but is notoriously tough to dig through and dispose of.

Getting rid of rock safely is a special concern, as falling rock could damage the dam's existing structures.

The heavy work high above the river could be risky for the 1,200 laborers expected on the project.

"The good news is we are able to do with equipment what used to be done manually," Zanetell said. "We take the workers out of harm's way."

The bridge will require 243 million pounds of concrete and 16 million pounds of steel to build.

Funds to finish the project were secured only earlier this year, when Nevada and Arizona offered $89.5 million in bond money to start work on the bridge.

That money will fill in for an anticipated federal grant that has yet to arrive. The cash is part of a transportation funding bill stalled in Congress.

The bridge had been planned for more than two decades before the bulk of funding, from the federal government, came on line in 2001.

"The push that got us here is homeland security, 9-11. That's why we're here now," Reid said.

That's because the dam has been off-limits to trucks since the East Coast terror attacks of 2001, forcing more than 2,000 trucks a day to cross the river on U.S. Highway 95 at Laughlin, a detour of about 23 miles.

Bids for the bridge work were opened last month and the contract will be awarded on Nov. 1. A collaboration of two multinational firms, Obayashi/Mitsubishi PSM, was the low bidder at $114 million.

That is about $12 million over expectations, but the entire project is around $15 million under budget, making the overrun a wash.