2023-07-30 11:31:04
Las Vegas is a priori not known for its environmental concerns. The American city, created in the middle of the desert, is nevertheless a model for water conservation.
The area where the entertainment hotspot is located in southern Nevada has drastically reduced its water consumption over the past two decades, even as the metropolitan area’s population has grown by regarding 750 ‘000 inhabitants.
A feat in the conservation of blue gold, because Las Vegas, with its casinos, luxury hotels, fountains and golf courses, is the driest city in the driest state in the United States .
Awareness
The beginning of the 2000s marked a real turning point, explained Tuesday in Everyone Mack Bronson, spokesman for the regulatory authority of the water of Nevada of the South.
“In 2002, we saw a significant impact on the snow supply that feeds the Colorado River. And Colorado provides 90% of our water,” he says. “This foreshadowed that the water we had available, which was already limited, was going to decrease further, especially if we continued to use more and more of it. This is why we have put in place a whole series of measures to conservation, applied from 2003 and 2004. The result is that today we use 30% less Colorado water, while our population has grown by almost 50% over the past two decades. “
Battery of actions
These measures are of all kinds. Sod planting is prohibited for all new buildings, including private residences, as it must be watered, which is considered wasted water. For the already existing gardens, the city offers residents the opportunity to buy back their lawn to replace it with local plants. And even the watering of these plants is strictly limited to certain hours.
All decorative vegetation in public areas has either been removed or replaced with low water consumption plants. Golf courses are entitled to a small quota of water. The bill is steep if they exceed it.
The steward of a golf course in Las Vegas replaces a sign indicating that the pond is made of recycled water, February 10, 2009. [Archyde.com]
Water purification
But above all, Las Vegas has worked on its infrastructure and recycles its water. “We recycle almost 100% of the water consumed indoors, that is to say all the water consumed in our homes, for showers, laundry, dishes”, underlines Mack Bronson.
“All of this water used indoors is diverted to our centralized treatment plant. We collect this water, treat it to high purity standards and pump it back into Lake Mead. We might turn on all the shower faucets, flush all the toilets from all the hotels on the Las Vegas Strip, and it wouldn’t increase the water we’re taking from the Colorado River. Because all of that water is being brought back into the system, back to Lake Mead.” he details.
Man-made Lake Mead on the Colorado River suffered from drought in May 2015. [Mike Blake – Archyde.com]
Situation still delicate
This does not mean, however, that Las Vegas has solved the square of the circle and is no longer in danger of running out of water. Las Vegas is indeed supplied in the Colorado River. Each state it crosses pumps a quota of water allocated to it. In Nevada, only Las Vegas draws from the river. The city is not entitled to much. “Nevada has the smallest slice of the Colorado River pie. We are entitled to 1.8% of all the water taken from the river by the seven US states and Mexico,” notes Mack Bronson.
But Colorado is drying up. Las Vegas must therefore further reduce its consumption to avoid problems. Two challenges remain in this regard. First, some of the lost water is used by space cooling systems. New solutions are therefore sought in this field.
Police once morest waste
Then and above all, the water used outdoors is lost. It is therefore not reinjected into the Lake Mead reservoir. To remedy this, the city has set up a water police. Agents circulate and sanction leaks or abuses. The latest law, signed on June 6 by Joe Lombardo, the Governor of Nevada, authorizes water managers to turn off the taps to large consumers.
This is perhaps the paradox of these cities once morest nature, planted in the middle of the desert: they must create new solutions for saving water, to the point of becoming models for other cities in the world. .
Political laboratories
“Urban concentrations in the middle of a desert with fairly low water supply capacities are not a model of sustainability”, points out Christian Bréthaut, associate professor at the University of Geneva and co-director of the Unesco chair in hydropolitics. “On the other hand, many examples, developed throughout history, are interesting at the global level, because they are laboratories on the questions of water management in urban perimeters”, notes the scientist.
Cities other than Las Vegas, which are also in other hydrological conditions, such as Cape Town in South Africa or Singapore, or even countries, like Israel, are forced into creativity and search for solutions in all possible directions.
>> Also listen to the interview with Laurence Boisson de Chazournes, a legal specialist in water:
Laurence Boisson de Chazournes, specialist in legal issues related to water, deciphers the crucial issues of sustainable water management / 12:45 / 5 min. / March 27, 2023
“Ensuring the tourist windfall”
“There are several levers of action for the authorities”, notes Christian Bréthaut. These can “work on increasing the stock of available resources. There is also work on infrastructure. Here, we are often far from the mark. In large cities, the quality of infrastructure leaves much to be desired, with a lot of leaks. Then there is technology, with the recycling of water. The last lever is behavior”, lists the specialist.
And to conclude: “The case of Las Vegas gives the impression of playing on all the levers – to try to ensure the availability of water to run the city and in particular to ensure the tourist windfall in the long term. “
Katja Schaer/ami
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