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Comment by digdugdirk | Hacker News Reader

Has there been any research into what areas will be the canary in the coal mine for when things go bad bad? Aquifers, rivers, lakes, etc - I'm curious if it's possible to follow the watersheds from the continental divide and determine what the key choke points are.

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I'm not sure what makes you think things aren't going bad bad right now and people aren't paying attention.

I think Bad bad will be a major metro loses reliable water service across their jurisdiction. It would be a major region of the US running out of basic foodstuffs across the board (though logistics of moving food is easier than water).

The current disasters are amplifications and slow creeps of things we've seen before, heat wave, fire, drought.

It's not going to be just one metro. Water planning and distribution focuses strongly on making sure pretty much everyone has at least some water. If water ever becomes too scarce, everyone will feel it at once.

The slow creep is the warning sign -- according to experts we should be doing a lot more than we currently are right now.

Typically water delivery is done to several 'tiers' of customers, where the top tier is consumers. Farmers sit below that and industry below that. This sort of thing will have massive effect, especially if it lasts longer than a few days or weeks, at some point vegetation will die off, cattle will die and people will start moving.

Everyone in that geographic area. We don’t have any ability to move water across the country at present.

Nor should we. There is no reason to build pipelines to send fresh water to the desert.

Why not? It is a hell of a lot cheaper than moving people to the fresh water.

In the long run it isn’t.

I don't think that is at all clear. Building a pipeline has a financial and environmental cost, but so does moving 10s of millions of people.

There are only two sources of water that are "free" (as in not already heavily taxed for human use) and that would really move the needle on the Southwest's water supply: the Canadian Pacific Northwest (Yukon & McKenzie River Watersheds) or, even more quixotic, the Mississippi.

To move that water, in either case, you have to maintain a sufficient drop in your canals/pipes to keep water flowing and prevent sediment buildup. This means that building a flat tunnel across 1000 miles, including through mountains (already an obscenely expensive proposition) is out of the question--you have to pump water up to allow it to flow downward. The energy costs--to speak of nothing else--would be incomprehensible. IIRC, damming up every possible spot in North America wouldn't suffice to provide the energy required.

More to the point, we've already put way more water in the desert than was ever there naturally, and we've irrigated perhaps 10% of it. People always want more. We've already surpassed the long-term carrying capacity of all watersheds within 500+ miles. If we pump more water in from elsewhere, we're just kicking the real problem down the road and making it worse for a future generation. There will never be enough water.

I highly recommend reading Cadillac Desert, it really clarifies this issue.

You're right. Major crop failure (especially in the Midwest) would be a real bad thing. Far worse than a major city running out of water.

I'd watch the various Great Plains aquifers. I think the main outcome of drying isn't going to be thirst, but hunger, and that's the area to keep your eye on for when that'll really kick into high gear. Those aquifers were on track to dry up absent climate change, AFAIK, from severe overuse by agriculture.

Yes, very much, so: https://en.wikipedia.org/wiki/Ogallala_Aquifer is what I think you're talking about. https://www.pnas.org/doi/10.1073/pnas.1220351110 is depressing reading.

https://en.wikipedia.org/wiki/Nubian_Sandstone_Aquifer_Syste..., also.

Florida is also a large source of many crops, particularly off-season, and they are damaging the Florida aquifer through overuse which is being exacerbated by saltwater intrusion due to rising sea levels (rain falling over land creates hydrostatic pressure along the coasts): https://www.nationalgeographic.com/science/article/partner-c...

Shallow wells running dry would be a pretty good early warning sign.

See:

https://theconversation.com/water-wells-are-at-risk-of-going...

The Colorado River Basin states are already in crisis mode. The governors just agreed to some emergency action that may head off the worst but drought conditions are expected to keep going so who knows if the reservoirs will recover.

This is a very good question. The world, and in particular the US and its local geographies, are very well interconnected. I think the "bad bad" is at the systemic level of these interconnections, no single element will point it out.

Move to coastal California. There's enough sun & ocean water to fall back to desalination if need be.

I suspect Arizona will be screwed as they've had a housing surge without similar investment in securing new water sources.

Re: California, not if nimbyism prevails. The brine discharged from a desalination plant is an environmental concern.

https://calcoasttimes.com/2022/05/14/california-coastal-comm...

Aside from nimbyism, replacing natural fresh water source with energy-intense desalination isn't a solution, especially not in the short term. We're already using way too much energy, and at the current rate of decarbonization it'll be decades to a century until climate change will be getting better. Solving the problems brought about by climate change with using more energy will just set us up for a dead spiral.

The problem isn’t that we’re using too much energy. It’s that we aren’t producing enough carbon neutral energy.

Residential use is a tiny % of total use. There is a lot of unnecessary water use in agriculture, lawns, etc that would give before any individual resident is meaningfully affected.

In our water district, we're already at 8 minutes per week of irrigation. With threats of going to 0 minutes per week. Normally we're allowed 45 minutes - 15 minutes, 3x a week.

> that would give before any individual resident is meaningfully affected.

I think we're a lot closer to this than you seem to think.

California has seen droughts before and is currently more at risk than ever before: https://drought.ca.gov/

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