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LAKE MEAD INTAKE NO. 3 LOW LAKE LEVEL PUMPING STATION
UNDERGROUND

With the world’s deepest submersible pumps, the Low Lake Level Pumping Station can deliver up to 900 million gallons of water per day to Southern Nevada’s 2.2 million residents and 33 million annual visitors.

The pumping station, which draws water from Lake Mead's deepest intake, is part of SNWA's response to a persistent, decades-long drought in the Colorado River Basin. Barnard, as the CMAR, joined the project at the 50% design stage to provide insights on constructability, value engineering, cost estimating, and schedule. When the project moved into construction, Barnard self-performed the drill and blast excavation of the forebay, access shaft, and riser shaft. Upon completing the underground works, Barnard worked with a specialty subcontractor to drill the 34 pump shafts to precise tolerances. We subsequently installed the custom pumps, each weighing between 68-79 tons. Under separate contracts, Barnard constructed the large-diameter discharge aqueducts that deliver water from the pumping station to SNWA's existing water conveyance infrastructure and an electrical substation that powers the pumping station. All work was completed on time and below budget, with SNWA activating the pumps for the first time in April 2020.

OVERVIEW

Location: Boulder City, Nevada

Owner: Southern Nevada Water Authority (SNWA)

Engineer: MW/Hill A Joint Venture

Construction Manager: Parsons

Contract Type: Construction Manager at Risk (CMAR)

Status: Completed

HIGHLIGHTS

  • 2021 American Society of Civil Engineers Outstanding Civil Engineering Achievement Silver Award
  • 2020 ENR Southwest Project of the Year
  • 33-ft.-wide by 36-ft.-high by 377-ft.-long horseshoe-shaped forebay cavern
  • 535-ft.-deep access shaft with 26-ft. finished diameter
  • 80-ft.-deep riser shaft with 26-ft. finished diameter
  • 34 drilled 8-ft.-dia. by 500-ft.-deep well shafts with steel-lined 6-ft.-dia. casings
  • 34 30 MGD submersible pumps
  • Valves and discharge headers
  • Structure to house electrical controls and starting equipment
  • Surface piping connecting new pumping station to water treatment plants

377-ft.-long forebay cavern

58,000 CY of blasted rock

271 controlled blast rounds

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