This desert city has figured out innovative ways to cut down on leaks
America's water infrastructure is in crisis. Seven hundred water mains burst a year, costing the U.S. about $3 billion in lost water. As David Lepeska wrote this week:
The problem is most troubling in cities, where dense and increasing populations put greater demand on already-strained systems that municipal governments generally lack the funds to upgrade. Without robust, urgent action, the Environmental Protection Agency estimates that nearly half the nation's pipes will fall into the “poor, very poor or elapsed” categories by 2020, risking widespread failures and a considerable threat to public health.
Some cities have begun to replace their aging systems by leveraging new taxes on water users. But cities might be able to improve their system's efficiency without an expensive overhaul.
The first step is getting intimately aquainted with the pipes and pumps that provide a city its water, according to Tom Curtis of the American Water Works Association. This means understanding exactly which pipe is where, how long it's been there and how much longer it'll last.
If cities can do this, they can do more than just anticipate leaks. They can replace their systems gradually, rather than embarking on an expensive, across the board upgrade.
Ground zero for this type of thinking is Las Vegas. "Water is so scarce and precious that they can’t afford to have leaks," Curtis says. "They’ve been very aggressive at the efficiency of water delivery."
Las Vegas began building its current water infrastructure system in the 1950s. It grew rapidly in the 1980s and 1990s, and now encompasses some 4,000 square miles of pipes. According to Kevin Fisher, director of operations at the Las Vegas Valley Water District, the system protects against leaks in several ways.
For one thing, there are between 7,500 and 7,800 leak detection units distributed throughout the city's system. They're programmed to register anything that sounds like a leak. An employee visits each unit at least once a month and, if necessary, quickly dispatches a team to track where a leak is coming from.
The city also put an aggressive water conservation system in place, instituting laws about how much grass residents can have, setting water budgets for golf courses and installing time-of-day and day-of-week water restrictions. It paid off: water use was 32 billion gallons less in 2010 than in 2002. This despite the fact that the city population grew by 400,000 in that time.
"This takes off stress on the system," Fisher says. "Moving more water leads to more leaks."
But Las Vegas's most valuable tool is its asset management program. The city keeps a careful record of every part used in their water system: they know how old it is, when it'll need to be replaced, and how frequently it'll need maitenance.
This information allows officials to proactively replace parts before they cause major damage. Additionally, the city doesn't waste resources on parts that will be phased out. Engineers keep careful track of which pumps and valves work the best. This allows the city to spread out the cost of replacements over several years.
Fisher says that this system has saved Las Vegas money, a rare occurence these days. "We're making better decisions in the field," Fisher says.
Photo credit: Steve Marcus / Reuters