24.5 Trillion Gallons of Water | Hacker News Reader

24.5 Trillion Gallons of Water

washingtonpost.com

38 pointsjostmey57 comments

My favorite statistic is that 24.5 trillion gallons of water is 75 million acre-feet, or slightly more water than all California agriculture uses in 2 years.

The water "shortage" is more of a distribution problem.

Same with food, money, housing, etc.

I've heard this happen specifically with potatoes at some point in history.

My next startup will just be a shed full of potatoes

Will be targeting the English market

Acre-feet? Is this a satirical unit of measurement?!

That's common for water allotment and agriculture. Western water rights allow for users to take only a limited number of acre-feet of water per year. If there is less water, then some people get bumped off the list for that year.

I'm not a farmer but I would guess it's serious. Land area is measured in acres, and the amount of water that crops need per growing cycle could be measured in feet, hence acre-feet.

An acre-foot is the amount of water required to cover a one acre area in one foot of water, or about 1.2 million liters.

1 acre covered in 1 foot of water. Makes sense where farmland is measured in acres, and actually probably a bit easier to visualize than "10^6L"-- though I know what you mean.

Hmm... so 10^6L would be 0.1 hectare meters. Acre feet may be easy to visualize, but it's hard to convert.

Nope. A really common one. It's about the annual use of an american household, as well:

https://en.wikipedia.org/wiki/Acre-foot

It's serious, probably because reservoirs and inundated lands are conveniently measured in acres of area, and depths of water in feet.

For water resources and agricultural uses, it's (given that you are using US Customary units for length and land area to start with) a reasonably sensible unit.

It's roughly 150 trillion cubic microfurlongs, if we want to get silly about it.

By my math, if that were a single spherical water droplet, it would be almost 3.7 miles in diameter.

If you have trouble visualizing this (as I do), the height of the Empire State Building is 0.2 miles. So imagine a sphere of water 20 times taller than the Empire State Building falling on New York.

Of course, the area and rate it falls on is crucial, but as a way to think about the scale of it I found this useful.

Edit: just saw this was done nicely by the article dreamcompiler linked to!

There's been a bit of discussion about how Houston is prone to flooding to begin with because there's no zoning, etc.

This Guardian article was written 2 months ago:

“Where the built environment is a main force exacerbating the impacts of urban flooding, Houston is number one and it’s not even close.”

https://www.theguardian.com/environment/2017/jun/16/texas-fl...

A more recent Atlantic article:

https://www.theatlantic.com/technology/archive/2017/08/why-c...

These are rather viewpoint-based articles. As a thought experiment, test their cause-and-effect explanations against the historical floods that Houston has experienced since it was originated by the Allen brothers. Houston had terrible floods even in the 1920's and 30's. There was very little concrete and pavement in those days, especially in the areas they claim are lost prairie.

Saying there were bad floods before and there are bad floods now doesn’t negate the claim that humans have made the problem worse.

http://www.npr.org/2017/08/27/546603361/houstons-explosive-g...

Nothing in that article demonstrates that the flooding was made any worse by any of the claimed mal-administration. The only demonstrable difference these days is that very heavy rainfall events are more frequent, and more severe. Which does not support the hypothesis.

Edited to add: I will grant that there is more damage, because there are more structures now. Also that many of the structures built in the last decade or so a infill in flood-prone areas. So that's a good candidate for mal-administration. But the theory that the actual floods are worse, in terms of area flooded, flood depth, etc., is not supported IMO without better science. Could be true. But what we know for sure is it's raining more.

Hey, have you followed up with this story? Turns out could be true, is true.

There are ~500 cities with population over one million, so I think we are going to be seeing a 500-year disaster hit a million-plus city about once a year.

Sampling a timeseries is not like sampling an ensemble. But nonetheless I agree we will probably see many more large-scale climate events than we have.

This includes a visualization of a "cube" that doesn't have parallel planes. I'm not sure how much I can trust that lol

That' almost 100 trillon litres. In a few hours it is.

So 1 with 14 zeros after. A cubic meter is 1,000 litres. So we are talking 100 billion cubic meters. Or the same as 100 cubic km.

Or the same amount of water as in a deep square lake which is 10 times 10 km wide and 1 km deep.

Or a square lake which is almost 32 km on each side and 100 meters deep.

Or a shallow square lake which is 1 meter deep and roughly 317 km on each side.

I prefer all my lakes to be hexagonal or octagonal - please edit your comment.

As they say: Is that a lot? I hate the way headlines measure things in useless units, just to get a bigger exponent. Why didn't they say it was 19000 trillion teaspoons? That's just as easy -- i.e. impossible -- to visualize. I think a possibly easier-to-visualize description is enough water to cover the whole state of Texas six inches deep.

The diagram of the huge cube of water hovering over the city wasn't enough to help you visualize that it's a huge amount of water?

They included several other visualization descriptions in the article. They can't put it all in the headline.

24.5 trillion gallons of water is a huge problem... and also a huge resource. It's just in the wrong place, right? What if we had a system for rerouting water dumps like this around the country and could send it to a drought region?

We have interstate highways. How about interstate drainage?

Well, I guess that's what rivers are....

Another nice visualization: https://www.vox.com/science-and-health/2017/8/28/16217626/ha...

That's it! We need a new unit of volume to replace gallons. A gallon is way too small. A barrel is difficult to understand. If only we had something standard like swimming pool or something...

24 climate-change units of water?

Melted Icebergs of water.

So basically, we need a pipeline from Houston to California.

Yeah, and the pumps/tunnels to get it over/under the Rockies and the Sierras.

US already has a wall to build.

To make at least a dent in Houston's problems, it would have to be able to move 10 trillion gallons in a few days. But, hey, let's give it all year, just to make it easier. That's 27 billion gallons a day, just over a billion gallons an hour, 19 million gallons a minute, or 317,000 gallons a second. That's... improbable. That's 508,000 cubic feet per second.

Assuming a velocity of 1000 miles per hour, or 1467 feet per second (also improbable), you'd need a cross section of 346 square feet. That's a pipe that is 21 feet in diameter, which is not completely impossible. Or four pipes that are each 10.5 feet in diameter. That's doable. The 1000 miles per hour pumping speed is a bit of an obstacle, though...

California has only 20 million acre feet of reservoir capacity, which is currently filled to 125% of typical levels. The last thing that state needs is another 75 million acre feet of water.

A pipe delivering enough to refill groundwater levels in CA would still be very useful though...

We could have a "water your lawn" day and use up a bunch without touching the reservoirs.

California has very roughly a billion acre-feet of groundwater capacity[0], and it is so severely depleted from being pumped out to cope with surface-water shortfalls over the years that the Central Valley is sinking (and eroding groundwater capacity in the process.)

California doesn't need 75 million more acre-feet of surface water, but it could probably benefit from multiples of that being pumped back into the ground.

[0] CA Dept of Water Resources estimates between 850 million and 1.3 billion, http://waterinthewest.stanford.edu/groundwater/recharge/

You jest, but there are serious (abstract) proposals[2][1] to build inter-regional water banking mechanisms, such as pumping water from flood years in the Missouri/Mississippi watershed to be stored in CA/NV aquifers, and vice versa. It's not a bad idea.

[1] http://www.hcn.org/issues/47.4/the-water-czar-who-reshaped-c...

[2] https://www.reviewjournal.com/news/exit-interview-mulroy-tal...

NYC has reservoirs close to 500 billion gallons of water combined. And the water level only goes down to 80% during the summer.

If my math is correct, that would be 2.6 hours of foz de iguaçu falls.

Fyi...there are no basements in Houston (or Texas really) despite what the article states about how water will have to be pumped out of all the basements.

Can't view the page. It blocks me because of ad blocker.

It works for me with Firefox and uBlock Origin.

https://addons.mozilla.org/en-US/firefox/addon/ublock-origin...

uBlock doesn't work with Nightly yet :(

RC works fine so far

https://addons.mozilla.org/en-US/firefox/addon/ublock-origin...

awesome, thank you! Have you tried uBlock + ghostery together, necessary? conflicts?

It is if you click on the "development channel" button at the very bottom.

Thanks for heads up!

It blocks me without ad blocker because it wants me to subscribe to continue reading.

Deleting "drawbridge-up" from the html tag and the <div id="drawbridge-root"> tree does the trick.

This has been working really well for wapo articles, https://outline.com/

Works for me as well, NoScript in default deny all javascript mode.

The take away is that there aren't likely to be technological remedies to the affects of climate change. Once the earths defense systems are triggered we simply die.

> Once the earths defense systems are triggered we simply die.

Citation/clarification needed. Does your 'we' mean 'all of us'?

To be clear, there are very few people who have been alarmed for as many years as I have been about climate change. And my alarm only deepens over the years.

It's hard for me to imagine a reasonable way that humans will become extinct. I can imagine billions of us passing away.

How is that a takeaway? The article didn't even mention climate change (and it's impossible to definitively attribute a single event to climate change.

How is a big wet storm a "defense mechanism"? Why would the earth even have active "defense" mechanisms? What it is it defending?

It doesn't seem like a very effective defense mechanism, so far reports are that there were only 20 - 30 confirmed deaths due to the floods out of 6 million in the metro area. While tragic in the real sense, more people than that must die of natural causes in the Houston area every day.

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