May '08 Our Diverse Community—Italian Community Column

On March 20, 2008, the Southern Nevada Water Authority awarded a $447 million design-build contract to Vegas Tunnel Constructors, a joint venture of Italian building company Impregilo and its U.S. subsidiary, S.A. Healy, to build a water intake tunnel at Lake Mead.

The 20-foot-diameter, three-mile-long concrete lined tunnel will be excavated under Lake Mead and will draw water from deep into the lake, where water is clean and protected from fluctuating lake elevations due to an extended drought in the Western United States. During the course of construction, a tunnel boring machine will be manufactured in Germany specifically for this project and shipped to the job site in order to complete the deep tunnel excavation.

“The new intake won’t add to capacity,” says Marc Jensen, SNWA Director of Engineering. “It will provide a better quality of water and act as insurance in the event one of our current intakes becomes inoperable.”

Construction will begin later this year and is expected to be complete by 2013.

The Italian based company Impregilo specializes in the type of excavation needed by the SNWA. Throughout the continent of Europe and especially in Italy, Impregilo has been shaping the landscape for railways and other construction sites. One major project Impregilo undertook was for the “Italian High Speed Train System,” which involved the improvement and re-designing of the old Italian National Railway Network. The new two-way railway line is 78,482m long, of which 73,316m are tunnels (including cut and cover sections for a total length of 1,490 m), 5,166m open-air works and 1,071m are bridges or viaducts. The new railway line which just completed construction this year began back in 1998.

It includes:

· 9 tunnels

· 11 bridges

A junction with the existing rail line network Bologna-Florence at San Ruffillo, near Bologna
6 reinforced concrete or steel/concrete mix bridges
Earthmoving works for rail embankment construction, including land reclamation and minor structures
Superstructures and electrical plants, signaling, telephone connections, lighting, safety and remote control, power installations
Civil and industrial buildings
Diversion of local roads and relocation of public utilities
Preparation of the spoil areas
Temporary worksite areas
Social and environmental impact mitigation works, including construction of roads, car parking, water supply network, landscaping works.

Impregilo has also built railways, roadways and subways around the world, from Switzerland to Venezuela. They have also built two hospitals in Great Britain, completing their construction in 2003 and 2008.

The St. Gothard railway tunnel in Switzerland may be considered the essential part of the overall project called AlpTransit, which the Swiss Federation intends to modernize the existing railway network crossing the Alps, especially with regard to the new European High Speed Train System. The project connects the cities of Milan and Zûrich, both from Bodio (Canton of Ticino) and Erstfeld (Canton Uri) portals.

Another huge contract that Impregilo took on was The Kárahnjukar Hydroelectric Project, which was completed in December of 2007 in Iceland. The project when it was actually under construction was considered the most important for the nation. The main purpose of the project was to store the glacier waters of the river Jokulsa a Dal in the Halslòn reservoir. The waters are then conveyed to an underground powerhouse.

The purpose of the contract was the construction of a concrete-faced rock fill dam. The dam is the biggest ever constructed in Iceland and one of the highest, of this type, in the world.

As for the work at Lake Mead, the job is considered dangerous. The company will excavate a 20-foot-tall concrete-lined shaft 75 feet below the lake bed. In the end, the tunnel beneath Lake Mead will keep water flowing to Las Vegas even if the reservoir were to drop another 120 feet. The project’s completion in 2013 will include:

· A new pumping station inside Lake Mead’s Saddle Island

· A pipeline linking the third ‘straw’ to the valley’s two existing water intakes and treatments plants

· The new intake will draw water from the Boulder Basin, one of the deepest points