Lake-Mead-Intake-No3-pumping-station-suspended.

Lake Mead pumping station suspended.

Pictures.

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(Caption) Area Map of Lake Mead

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(caption) Band indicates drop in water levels.

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(Caption) Blasting on Saddle Island for access shaft

Lake Mead pumping station suspended Apr 2009

Paula Wallis, Reporter

Five bids came in last month, all well below the Engineer’s Estimate of $105 million, but it wasn’t enough. Funding shortfalls forced the owner to reject the bids and suspend construction of the new pumping station on the deep intake project at Lake Mead.

Since advertising for bids the Southern Nevada Water Authority (SNWA) prepared its budget and funding projections for the upcoming fiscal year and had to scale back its plans and cancel the contract.

“The local impacts of the developing global financial crisis are continuing to exert financial strain on our capital program budget,” said Robin Rocky, spokesperson for the Authority. “Revenues from charges for new water connections have dropped dramatically and we are assessing every opportunity for limiting capital expenditures as much as possible.”

According to the SNWA revenue from new water hookups dropped from $188.4 million in 2006 to a mere $61.5 million in 2008. In the first six weeks of 2009 reserves in its construction fund dropped 6 percent to $480 million putting severe strain on the Authority’s ability to repay the $500 million in bonds it plans to start selling later this year to complete the Lake Mead project.

As a result the SNWA is deferring major components of the Intake No. 3 Pumping Project for several years, by adding more pumps to increase capacity of the exiting Intake No. 2 completed in 2000 by Kiewit (operating as Lake Mead Construction).

KW Pipeline Inc., dba Renda Pacific entered the lowest bid at $78.7 million followed by the Vegas Tunnel Constructors, lead by Impregilo, at $86. 1 million, Clark Construction Group, LLC with a bid of $86.5, Kiewit Western Company at $88.2 million, and Barnard of Nevada at $99.1 million.

“Rejecting all bids on the pumping station will give our staff time to reevaluate and repackage the work to include only those components deemed necessary to assure water supplies are reliably conveyed through the new Intake No 3,” said Rocky.

The Authority’s decision is not impacting the major tunneling component of the Intake No3 project. The Intake Shaft and Tunnel contract was awarded in March, 2008 to the Vegas Tunnel Constructors – a joint venture of Impregilo Group and its U.S. subsidiary, S.A. Healy with Aurp as designer.

Construction of the $513 million design-build contract began June, 2008 with the access shaft on Saddle Island. As of April 2009 crews had excavated about 300ft of the roughly 640ft shaft.

Once complete, a Herrenknecht TBM, currently in production in Germany, will take over for the roughly three miles (4.8km) drive to an intake shaft on the bottom of Lake Mead about 600ft (182m) below water level. The project also includes a connection tunnel from the new intake to the existing No2 intake about 3000ft (915m) away.

“This No 3 intake will be a challenging project,” said Michael Feroz of Parsons Water Infrastructure and Principal Construction Manager of SNWA. “The new intake lies 200ft (60m) deeper in the lake than the existing intakes, both of which are also tunneled structures- the first built in the 1970’s and the second in 2000.”

Feroz said while those tunnels were drill+blast excavations, the new tunnel is a TBM operation starting in the open mode but having to go into closed slurry or EPB pressurized mode as the tunnel advances into softer formations where the heading might be subjected to as much as 600ft (182m) of hydrostatic head in the lake above.

Geological investigations indicate that Saddle Island is a block of Precambrian amphibolites and gneiss with the oldest known rocks in the area dating back 1.7 billion years. The alignment then moves into softer rocks and the water bearing silts and sands of the Muddy Creek Formation created by ancient rivers 5 to 11 million years ago.

The project is being driven by the worst10-year drought to hit the region in recorded history. Lake levels have been dropping about 1 percent a year since 1999 and by 2012 its surface could drop below the existing intake that delivers 40 percent of Las Vegas’ water supply.

Intake No3 is expected to be online by 2012.