Even if you don't live in the Southwest, scientists say everyone in the U.S. should be concerned about a shrinking Colorado River.
"Looking at Lake Mead, it's really evident just how much the lake has declined over the past 20 years with the white bathtub ring that you can see along the shoreline," said Southern Nevada Water Authority's Bronson Mack.
Mack says 40 million people depend on water from the Colorado River.
"And if we don't all adapt and reduce our water demands collectively, we're going to end up in a situation where demand is going to exceed supply," Mack said.
David Kreamer, a hydrologist at the University of Nevada Las Vegas, says Lake Mead, which is fed by the Colorado River, is only about 100 feet above what is called "dead pool."
"If the lake goes down to a dead pool level, about 950 feet above sea level, no more water can go through Hoover Dam and go downstream to California, to the crops and the fields that are located there," Kreamer said. "And that would be a pretty tremendous impact, not only for the Southwest but for the entire United States."
Kreamer says it would take about a decade of considerable snow and rain to replenish levels. Since weather can't be controlled, Kreamer says a quick solution is water conservation by incentivizing water savings.
Neighborhoods all over Southern Nevada have been ripping up grass for cash, replacing it with rocks, artificial turf, and desert plants. To replace the grass, Kam Bryan, CEO of Par 3 Landscape Management, says they use an herbicide, let the grass dry up, go back in a few weeks and power rake the grass, and then they go back to put in new trees and plants.
"Nevada passed a law about a year and a half ago that requires all commercial, and that would include homeowners associations, to remove all grass," Bryan said. "That is what they call nonfunctional. So if you can't play on it."
Southern Nevada Water Authority says it pays property owners three dollars a square foot to replace the grass with water-efficient landscaping.
"We have removed more than 200 million square feet of grass and collectively saved more than 170 billion gallons of water simply by taking out grass that nobody is using," Mack said.
It's part of a series of incentive programs, Mack says, the Las Vegas area implemented in the early 2000s.
"Providing those financial incentives definitely has been a key to our conservation success," Mack said.
Now, the rest of the Southwest is looking to Southern Nevada as a national model in conservation efforts.
"Just recently, 30 cities throughout the Colorado River Basin, in nearly every state of the Colorado River Basin, signed on to a conservation memorandum of understanding, all agreeing to implement best practices when it comes to water conservation," Mack said.
Mack says water conservation isn't a one-size-fits-all solution, but collaboration between communities will help as they navigate the future of limited water supply. Other water conservation solutions include seasonal watering restrictions, pool cover rebates and rebates for irrigation controllers.