必旺我头条 | 2022-09-03
For a city in the desert, water conservation must be a way of life. But amid a prolonged megadrought that has depleted water resources across the Southwest, the need to save every drop has intensified in Southern Nevada.
Las Vegas knows the stakes are high, and it isn't gambling on Mother Nature to solve its water problems.
Instead, the city is betting on extreme water-saving measures to keep the taps flowing. Here's how it intends to win.
A home with a swimming pool abuts the desert on the edge of the Las Vegas Valley.
Las Vegans are no longer allowed to build giant swimming pools or spas at single-family homes.
The Southern Nevada Water Authority says there's been a proliferation of giant pools -- some larger than 3,000 square feet -- in recent years. The new building code limits new pools to no more than 600 square feet -- a move the Las Vegas Valley Water District says will save more than 32 million gallons of water over the next decade. The average pool size in southern Nevada is 470 square feet.
The idea was to prevent people from building pools that were more like "water features" at some homes, rather than recreational swimming pools, said Bronson Mack, public outreach officer for the Water Authority, which manages water resources for 2.2 million people including Las Vegas.
"A lot of these more affluent homes, they're not even occupied year-round," Mack told CNN. "And yet they have all of this water in their backyard."
The "bathtub rings" are seen around Lake Mead, a sign of how far the water level has dropped.
Most of the Water Authority's conservation efforts focus on outdoor water. But indoor water can be recycled.
"Water that we used indoors all gets reclaimed," Mack said. "We treat that water to clean water standards, then return it to Lake Mead, our primary water source. Every gallon that we return to Lake Mead allows us to take another gallon out of the lake without counting against our limited water allocation."
According to the Water Authority, only 10% of its water comes from local groundwater. The other 90% comes from the Colorado River's Lake Mead, the largest man-made reservoir in the country, which continues to fall to record lows. In April, the Water Authority had to decommission one of the original intake valves in the lake because the water level had fallen so low.
And in August, the federal government enacted a Tier 2 shortage, which will limit the amount of water southern Nevada can pull from Lake Mead beginning in January by about 8.1 billion gallons a year.
Yet, on the Las Vegas Strip, glasses of water may still be served to restaurant customers since all that water will be recycled.
"Even if you don't drink that glass of water ... they're going to dump that down the drain, and all of that water gets reclaimed," Mack said, noting this practice began in the 1950s. "That dish is going to go through the dishwasher -- all of the dishwasher water gets reclaimed and recycled back to Lake Mead."
The Bellagio fountain is an iconic feature of Las Vegas. It can lose up to 48 gallons of water per square foot per year due to evaporation alone.
As for the Strip, the economic engine of southern Nevada, Mack said the region's resort, casino and hotel sector is not as water-wasteful as it seems, despite its reputation for excess.
Mack said it only uses 5% of the community's total water supply, while also making up its largest employment base, supporting some 40 million visitors a year.
There are also limitations on swimming pool size for the resorts based on the number of hotel rooms and guests they serve.
"We could turn on every shower and every sink in every hotel room on the Las Vegas Strip, and it wouldn't increase the amount of water we deplete from the Colorado River because all of that gets cycled back through our wastewater system, gets treated and returned to Lake Mead," Mack explained.
As for the Las Vegas strip's iconic fountains? They lose a lot of water to evaporation. According to the Water Authority, the fountain at the Bellagio is fed from a privately owned groundwater well and doesn't use water from the Colorado River. But it estimates those outdoor water features can lose 48 gallons of water per square foot a year to evaporation -- in a place where every drop counts.
The canals in the Venetian Resort recirculate their water, which does come from Colorado River. However, since the water is used indoors it can be reclaimed, Mack said.
As the climate crisis intensifies and water resources decline, the Las Vegas Valley Water District is considering a ban on all new ornamental water features at resort hotels, unless the feature is completely indoors and supplied by a privately owned water source.
