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Comment by finfinfin | Hacker News Reader

> Residential water use has plummeted in the west. Some areas, like vegas, use less water than the 70s, not accounting for population changes.

What's the point of this argument? Vegas population has increased more than 10x since the 70s, why would we not account for population growth when discussing the usage of a limited resource?

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I think you misunderstood. Vegas uses less water in total than in the 70s, in spite of the population difference.

Does this include the suburbs of Las Vegas? A quick google search gives a report that the whole state of Nevada as a whole has increased their water use (edit: at least for domestic usage). This is in line with most of the population moving out of city centers as people moved into the suburbs that has happened for the last few decades.[0]

Anyway, the fact that the water use of the state as a whole has increased throws out any suggestion that "here, this one segment of the state has decreased their usage" as if that is a serious argument against the rise of water consumption being an issue.

[0] It's a report with data until 1995 but lucky for us it compares levels with 1970 and it did increase significantly EDIT: sorry, figure 1-3

http://water.nv.gov/programs/planning/stateplan/documents/pt...

Can't say about the 1970s, but there's a chart in this article showing that total water usage for southern Nevada has indeed decreased since 2002.

https://www.watereducation.org/western-water/climate-change-...

According to that graph 2020 usage is almost identical to 2003. So the only significant drop happened between 2002 and 2003. Not to nitpick, just to emphasize that the missing data from 1970 to 2002 could contain numerous large changes too.

I find this very hard to believe. Do you have any links to official state data?

The drop comes from two critical changes:

1. improvements in domestic water usage arising from changes to in-home fixtures and appliances. Per capita use in cities across the US southwest has dropped by 30% or more over the last few decades.

2. switching over to grey/recycled water usage for a huge chunk of municipal water irrigation (eg. city parks, highway medians etc.). This uses a significant amount of water, and switching to water that has already been used once has a dramatic impact.

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