What is the biggest pumping plant in the CAP system?

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Wilmer Plant

With 14 pumping plants in the 336-mile CAP system lifting water nearly 3,000 vertical feet across the State of Arizona, one might imagine these plants are massive and active and amazingly engineered.

Mark Wilmer Pumping Plant at Lake Havasu, the first plant in the system, is the largest.

Here’s the “tale of the tape” for Wilmer:

  • Six pumps at 66,000 horsepower apiece (approximation based on motor efficiency);
  • Pumps lift water more than 800 vertical feet into Buckskin Mountain Tunnel;
  • With all six pumps running, an Olympic-sized swimming pool would fill in about 23 seconds.

This plant is named for Mark Wilmer, a water rights attorney who argued in the Supreme Court for Arizona to keep its full entitlement to its allocation of Colorado River water.

Fittingly, Wilmer kicks off a journey of that Colorado River water to central and southern Arizona, each plant in the system moving various volumes of water onto the next.

CAP is the largest single power user in Arizona – water is heavy and lifting it across the state requires a lot of energy – and more than 50-percent of CAP’s energy use occurs at the work-horse plant that is Mark Wilmer.