Comments by "Laurence Fraser" (@laurencefraser) on "How do cities get enough fresh water?" video.

@michaelmichael2382 this is true, though grass (at least as used in most lawns) should be a much lower priority than it is. Also, When you water it is super important. Late evening is best. (No risk of the droplets causing lensing effects that damage the plants, And far less water is lost to evaporation.) Also, most other countries have less lawns than the USA, at least in areas that don't get enough rain to support the grass naturally. More proper farmland or high density housing, less suburban sprawl dumping huge amounts of water into unproductive uses like keeping the lawn green in the hottest part of the year (grass can, generally, survive the dry and heat of summer (in climates where summer is fairly dry), its leaves just go brown and dead in the meantime. But that doesn't look nice, so for maintaining lawns enough extra water is expended to simulate spring and autumn rains. Which is very wasteful.) Watering the plants that will actually die otherwise is perfectly reasonable (well, unless you've chosen Particularly unsuitable plants), likewise for food crops. Lawns, though, are mostly pure vanity, and in climates that don't naturally support them, utterly wasteful.
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Mostly because, on that scale, it's very easy for it to go very, very wrong. Also difficult Besides, the global water cycle being what it is, we're already doing this when the (mostly) cleaned up waste water is released back out into the environment. It gets evaporated and condensed and filtered and diluted in various ways as it cycles through that system before being recaptured and used again. Climate change is just problematically disrupting the old patterns of how much is where at any one time.
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Well, if you were just watering your lawn (Especially with those sprinklers that just clip onto the end of a hose and have no actual controls other than the incoming water pressure), he was probably right. On the other hand,if you were watering plants that actually need it (especially food producing plants) in a non-wasteful manner (actually going around and carefully only watering the bits that need it they amount that they need), then obviously not. Under normal conditions, at least.
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