A common misconception is southern Nevada and Las Vegas are huge water pigs. The opposite is true. Per capita water use has dropped since 2001, thanks to a smart region-wide water authority that encourages conservation and a world-class system that recycles and reuses every drop of water that goes down a drain or toilet, as well as saving rainwater, by letting it all flow back into Lake Mead where it is reused.
The entire rainwater capture system works by gravity. There are no pumps. Rain is captured in huge basins, flows downhill to water treatment plants, marshlands, Lake Las Vegas, then into Lake Mead. By law, southern Nevada can use 1.8% of water in Lake Mead. However, recaptured water does not count towards that total. It’s one of the most innovative water systems anywhere.
In the early 1990s, southern Nevada was headed towards a water crisis. One problem was there were seven water agencies. They joined together to create the Southern Nevada Water Authority, which shares resources.
The ability to band together to take collective action for the common good is a key to resilience in human systems.
The Southern Nevada Water Authority created a regional framework for the pursuit of conservation, and pursue it Las Vegas did. With publicity campaigns, restrictions on landscaping in new construction, and policies like lawn buy-back programs, Las Vegas residents’ water use began to drop. From 1994 to 2014, per capita water use declined by 36 percent. Conservation soon outstripped population growth, such that total water use peaked in 2002 and has been declining ever since.
From the comments. This is key. Charge more for water and people will use less.
Fun fact – in Nevada, it is legal for a water authority to raise prices with the intent of encouraging conservation in usage. Aggressive pricing of a scarce resource is a key driver in reducing Vegas’ water usage per capita, along with the other policies you mention. In contrast, In California water authorities can only charge for cost of service, which makes it much harder to reduce water usage per capita.