Las Vegas and Conserving Water

I was more giggling over the idea of strapping a 1-ton AWG outside my condo window to make drinking water:

Per the first article, and already mentioned by others, total. And also per the first article, it’s 60% residential use.

Everyone should.

That wasn’t clear, the article seemed to focus on residential use, but that does change the picture a bit, still way too high, though, recycling or no.

Yeah, I should have pointed out that my usage is not the norm here (anymore - it was unavoidably so in the drought). But it is eminently attainable.

Depending both on rainfall (and having a roof) and relative humidity (and having outdoor space for an AWG.)

Even adding in what we get from condensate and the amount we use from rainwater, we’re not using more than 70 l/person/day. I know because that was our usage before installing tank and generator, and our lifestyle hasn’t changed.

So some things about that lifestyle - we don’t flush urine, we only water some herbs by watering can, not a lawn (we have some lawn, but even at the height of the drought, the challenge was more to stop it growing than anything else), we don’t have a pool, and our appliances are all eco-rated.

Like I said, our water generator is the size of a water cooler. It works inside the house and provides drinking water to a family of 4 (~20 l/day) Yes, that will be humidity-dependent.

We got 4.17 inches of rain here in Tucson in 2020. That’s not going to go far.

My swamp cooler only works in low humidity. I’d assume (but please prove me wrong) that in humidity where my swamp cooler works pulling water out of the air would be wildly inefficient.

Doesn’t Vegas have close to 500,000 “visitors” per day.

You would think they would be included in the water usage totals. Perhaps that’s why they don’t make sense.

You’d save much more water (but use more electricity) by replacing the swamp cooler with an air conditioner, because after all, the swamp cooler works by doing the opposite of a condenser.

I had a quick look at my water bill for Sept-Dec. By then I think I’d turned off my sprinklers, so just household use. I live in an area with no issues about water supply, so no major effort at conservation; I think our worst offense is running the kitchen taps full blast to rinse dishes fairly well before putting them in the dishwasher. Thanks to covid, we wash laundry almost daily instead of twice a week; but its a front loader, and a house built in 2007 has the water-efficient dual flush toilets, better appliances, etc. We don’t try to avoid flushing (“If it’s yellow, let it mellow…”) We’ve been doing showers instead of baths since Covid started…

Basically, standard careless North American water consumption. So two of us in 3 months used 37.1 cubic meters of water, or about 200L a day each. And I’m sure with judicious water management we could cut that in half, perhaps.

My understanding is that in areas of the American southwest where water is scarce, even collecting rainwater is often not allowed - you’re stealing water that would end up part of someone else’s river water rights.

My dad’s house here had both an AC and a swamp cooler. He said a swamp cooler was much cheaper to run than the AC.

Legally, I am not sure it is possible. IIRC, you can not collect rainfall in California. I am not sure about Nevada or a place like Arizona.

That’s insane. Trapping it for use right away is way better than having it as runoff that never does any good. I can understand if it’s all going to end up in a dam, or a living catchment somewhere, instead, but given the realities of urban runoff, that’s not the case.

Since 2017 we Nevadans can collect rain water off a single-family home roof for non-potable use only.

Since we average fewer than 4 inches of rainfall per year here in Las Vegas, this isn’t really a big perk.

Wildlife needs it.

They’re not going to get much of it from urban runoff. And if they do, they won’t like it. Much better to trap it as rainwater, use it, and then it ends up in the water treatment cycle.

You are absolutely right, that thinking is insane.

I recall being involved in a thread some years ago where I set out the rationale. Others were arguing that banning personal rainfall collection was sensible because it deprived “water-rights” owners downstream.

Nonsense of course.

Detailed studies were done and only a tiny percentage of any water collected from a roof would ever find itself into the water course. And of course ultimately if someone has a usage of xL per day is it better to collect xL locally with full efficiency?
or let it hit the ground, undergo evaporation (and other wastage), have a small percentage hit the watercourse, travel downstream (further wastage) be extracted for processing (further wastage and energy use) transported back to the user (further energy usage) and only then does the user extract that same xL?

16 KL (assuming the US average 17 squares roof) is not nothing. It’s 3-5 thousand toilet flushes if you have a decent toilet.

It is possible the logic of disallowing the collection of rainwater might be related to mosquitos. There have been claims that barrels provide a reservoir for mosquitos which may increase certain diseases in certain areas. However, it also seems there are ways of mitigating this - so perhaps outright restrictions are not the best path.