Las Vegas and Conserving Water

Sinclair, in his book Lifespan, is making the point on the importance of conserving water with growing populations - that global population is less relevant than consumption.

“We also need to solve the shortage of fresh, drinkable water. Cities such as Las Vegas, a very thirsty town in the middle of the driest place in the United States, have demonstrated that by marrying conservation and innovation, efficient water recycling is not only possible but profitable; whereas metro Vegas grew by half a million people from 2000 to 2016, its total water use fell by a third.”

Hmm. I thought. Is this so? Google-fu led me to this article.

It discusses some intelligent reforms, and states:

“The efforts are paying off. Though total water use for the city rose only slightly between 2000 and 2010—by about 1.5 percent—Vegas added more than a million people. That works out to a 33 percent per person drop in water use. Vegas water officials hope to go even lower, with a per capita water-use goal of 199 gallons per person per day by 2035. That’s 20 fewer gallons a day than is used today.”

The savings sound impressive and important. But these two articles say different things (a per capita drop vs. reducing totals) and are hardly definitive anyway. So how big are the water savings in Vegas really? How do people feel about them?

Well, Albuquerque, which has taken water conservation seriously ever since I was a kid (seriously, it was covered in elementary school–simple things like turn off the faucet while brushing your teeth) is down to an average residential use of 56 gallons per person per day. Taking all water usage from all sources (so including residential, business, government, and so on) it’s more like 125 gallons a day. According to the city, that’s a reduction of 125 gpcd from around 250 gpcd in 1994. So my personal opinion would be it’s probably still not enough, with the caveat that Las Vegas has a very different source of supply. (Albuquerque is still somewhat aquifer, but a lot these days comes from diversion of the San Juan and Chama rivers).

The two articles presumably give different amounts because they’re looking at different timespans. It’s quite possible for both to be true. In any event, the bottom line of both is the same: Vegas is doing a good job of water conservation.

That said, the Albuquerque example makes it sound like they could be doing a much better job yet than they are.

I realized the time spans differ by a few years. But it is still unlikely (though possible) both are true.

If you’re interested in water management in general, you should also look at what Singapore is doing. I was there two years ago, and one of my tours discussed this issue a lot, and the things they were doing to manage their water supply were quite interesting. The tour guide pointed out one new building that had an almost completely closed water system. They re-processed almost all of their water within the building, with almost no top-up input from the city sources.

It’s possible one is looking at the city and the other the metro area, which has ~3x the population IIRC. Or even all of Clark County.

An image search for

las vegas water use by year

shows different plots with different boundaries.

This is true, but it does help that Singapore get 2.3 metres (91 inches) of rainfall annually while Las Vegas gets 0.01 metres (4 inches)

I’ve lived here for 25 years now and I can attest to the fact that we take our water conservation very seriously. And yes, we are noticably more xeriscaped today than the developed areas were when I got here.

I grew up mostly in the swamp; living in the desert took some adjusting.

It is personally horrifying to me that 753 l/person/day is seen as an aspirational water use goal for distant 2035.

That’s over 10x what we consume in our household. And we’re not exactly washing our butts with sand.

During our recent drought, we had it down to <50l/person/day

It seems kinda crazy high to me as well and I’m another wasteful American. In CA which is vaguely SA-like in terms of climate the current aspirational goal is about 208l/person/day (55 gallons), which a number of cities have recently managed to better (i.e. San Francisco was at 43 gpd in 2019-2020). During our own recent drought I was roughly at about 25 gpd with a largeish yard and was feeling reasonably good about that.

But now I don’t - 13-14 gpd is pretty impressive. Sure you weren’t using just a little sand :wink:?

Americans who live in single family homes do of course have this weird lawn obsession. That is only very slowly starting to break down in CA as drought becomes a way of life. Xeric landscaping is probably the way to go and some are starting move in that direction. But I do admit to having an attachment to lush English gardens - sadly they’re kinda wasteful in mostly Mediterranean climates like much of CA or high desert climates like Las Vegas.

Maybe they’re including swimming pools.

Based on the most recent data I could find, from 2015, the average Israeli uses 101 liters of water per day. God knows what the Americans are doing with all that water.

That total doesn’t include the condensed-from-air water we use for drinking (a machine the size of a watercooler), or the rainwater we capture ourselves for flushing.

So, you’re saying that Las Vegans should collect rainwater for flushing?

The Vegas figures also include non-residential use.

Rainbarrel collection did become legal there a few years ago. But only for single family homes.

I just looked up here that Cape Town water consumption (total for all purposes) was 793 megalitres per day as of last week.

The population is approximately 4 million, so that’s about 200 litres per person per day, or about 53 gallons, both residential and non-residential.

So for Las Vegas, 199 gallons per person per day by 2035… unless that’s used for irrigation… :face_with_raised_eyebrow:

Everything I can find shows that total water use for the metro area decreased. It’s possible that use for the city went up slightly, but I can’t find that number. And even then, it wouldn’t be appropriate for the second article to use city water use but metro population.

No, I’m wrong. Both articles are correct. It’s all about the dates. They used slightly more water in 2010 than in 2000, but less in 2012 and trending down.

Watering lawns. No, seriously. When it’s cheap with no restrictions, people will grow grass in the desert. They have since passed more regulations. The articles in the OP discuss this.

Is this per capita water use the total water use of an area (including industrial, commercial, etc.) divided over the population? Or is it actually looking at residential water use?

If it’s the former, it’s much more understandable, because something like 95%+ of water use is not residential in many places. If we’re dividing the total industrial/commercial/residential use divided by population and getting 200-300 gallons, that’s understandable. If we’re just talking about residential that sounds like too much.