Sipping from the Third Straw

Patricia Mulroy addresses a rapt WaterTech audience this afternoon.

“I’m not here to steal your water,” joked Patricia Mulroy as she took the stage this afternoon.

Funny she should say so. This year’s WaterTech, taking place in Banff, isn’t too far from Calgary, which is currently experiencing its own water shortage.

Mulroy is the general manager of the Southern Nevada Water Authority (SNWA), and, although she jests, water shortages are no joke to her. “The ten-year drought in the Colorado River has been devastating,” she said.

Southern Nevada relies on the tired, rapidly depleting Lake Mead for 90 per cent of its water (the other 10 per cent comes from groundwater). In just ten years, Mead’s elevation levels have dropped from approximately 1,225 to just over 1,080 feet—and they’re expected to be lower. “At 1,050 feet, we’ll see the end of the Hoover Dam,” said Mulroy.

Already it has two intakes to serve two million residents and 40 million annual visitors, but, due to Mead’s condition, Las Vegas’ first intake may soon be out of business. The SNWA has had no choice but to begin construction on a third “straw” at a lower elevation. The estimated cost? About US$800 million, including a $25-million tunnel boring machine. Despite the expense, said Mulroy, “failure is not an option.”

Not only is the first intake at risk, but now they face a new challenge: quagga mussels. The second intake (built in the mid-90s at elevation 1,000 feet) has been infested by this invasive species, she explained, showing images that make a Great Lakes-dweller like me shudder in fear.

In a chat prior to her talk, I asked Pat Mulroy if there were ever any other options for Las Vegas.

“There were no other projects. The only other alternative is to diversify where the water comes from, and that’s the next iteration. It’s not as if you could look at alternatives,” she said. “We’re racing the clock.”

Prior to beginning work on the third intake, they upgraded pumps on the second to higher capacity to ensure that they’d get through the summers of 2011 and 2012 if the drought beats the completion of the third.

When did real change start to take place? “We transformed everything in 2003,” she said. “We now recycle 100 per cent of all wastewater—whether it goes directly to a reuse facility and is delivered to parks and golf courses, or large tertiary plants that return the flow to Lake Mead. For every gallon of water we put back into Lake Mead, we can take out an additional gallon over our allotment. Since we can convert all our reuse water, we can increase our diversions to Lake Mead. Everything is reclaimed.”

What is Las Vegas doing to promote water conservation? They have a number of incentive programs, Mulroy told me. For example, for each square foot of grass removed from properties, customers receive US$1.50 per square foot. They’re also encouraged use desert-appropriate landscaping plans. “To date we’ve spent over US$130 million rebating to our customers to take turf out,” said Mulroy.

New construction must not have new grass; it must be desert landscaping. If customers want a fountain, they have to remove enough turf to equal 50 times the amount of water that the fountain would use in a year. Everyone is on a strict permanent watering schedule—they even have water cops, Mulroy told me. “We have a hefty fine schedule. You’re fined for every day you violate—if we see water running off your property, or you water on the wrong day, or you have a broken sprinkler head… we’re there to get people’s attention. Our water enforcement is going out to educate people.”

I asked Mulroy how the water shortage and restrictions have changed the behaviour of Las Vegas residents. “We’ve seen a huge paradigm shift,” she said. “We’ve been able to save 26 billion gallons of water. We drove our per capita consumption down from 365 down to 240 and have set a new goal of 199, and that’s diversion, so it will be way down there by the time we get to 199.”

The Bureau of Reclamation expects that Lake Mead will rebound “somewhat” over the next two years. What does Mulroy think about these claims? “I love it when they say those things because they’re predicting next year’s snowfall,” she said. “They want this [drought] to end just as much as we do. But those kinds of pronouncements are very annoying because they’re not borne in reality. You have to hope for the best and plan for the worst.”