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Sometimes I run the tap while i'm brushing my teeth and think about how when I'm old I'm going to look back on this and feel like an idiot.
July 10, 2012 1:21 AM   Subscribe

Assume I will live for another 50 years and that I live in North America. Will we "run out" of drinkable water in my lifetime? If not, how bad will the upcoming decades get as far as availability and pricing?
posted by radiosilents to Science & Nature (15 answers total) 11 users marked this as a favorite
 
It depends where you live. Some areas that depend on dwindling aquifers will be hit harder than areas with abundant areas of fresh water. Arizona will most likely be worse off than living in the Great Lakes Basin, for example.
posted by JJ86 at 1:39 AM on July 10, 2012 [1 favorite]


Wait, what?

Oy

For most regions water is not a finite resource, rain happens. Also check out how trends in water use have been changing over the last 60 years. Total water withdrawals have stayed constant, and even decreased by 9% over the last 30 years, even in the face of increased population. This is largely due to advances in the sectors that consume the vast majority of water in the United States, Irrigation and Thermoelectric power. We will never run out of potable water for drinking, the water you use to brush your teeth is such a miniscule amount of the total as to be an insignificant blip. That is unless you live in Southern California, Arizona, Florida, or some regions of the Great Plains. There total domestic water use does become a significant part of the responsible annual total and is worth considering, but still, if push came to shove, could always be serviced by forcibly (and painfully) reducing demand by farmers, industry, utilities, and the environment.

This is not to say that it is not important for other reasons. The water you used to brush your teeth must still be processed as waste water, which is expensive and difficult for your municipality. Also, if you live in a water pressed region, the less you consume the more becomes available for farmers, industry, utilities, and the environment.
posted by Blasdelb at 1:56 AM on July 10, 2012 [9 favorites]


Don't think of water like oil, think of it like parking spaces: There are only a finite number of parking spaces in a neighborhood, so the more people using them, the more scarce they become, but that doesn't mean that you will one day "run out" of parking.
posted by cirgue at 2:12 AM on July 10, 2012 [5 favorites]


Yep, water doesn't disappear, it just gets more expensive.
posted by jon1270 at 2:41 AM on July 10, 2012 [1 favorite]


Even if existing sources of water were exhausted by some eventuality, nanotechnology seems to offer a variety of potential approaches to drastically decrease the cost of desalination that may compensate as they become viable. So it could actually be easier to get drinkable water in the future.
posted by XMLicious at 2:44 AM on July 10, 2012


I think this is heavily dependent on where you live in North America.

Most of the major settlements in the High Plains and in the Southwesterns deserts are possible because they've found ways to draw water up out of the local aquifers to supplement the water they get from the rivers, etc. It took a while to figure this out, which is why much of the American West remained "The Great American Desert" for a long time. And aquifers are actually a finite resource: as you draw water up out of them, the rock that used to hold the water settles down and compresses. They used to think that you could just inject more water back into the old aquifer, but as far as I know, that has never been very successful. And I've read that the engineers and hydrologists who started tapping the Ogallala Aquifer about 30 years ago, which is one of the largest aquifers in the world and runs along the north-south access of the High Plains, were pretty sure that if they continued tapping it at the same rate, they'd run the Ogallala dry in about 50 years.

Also, most cities and farms/ranches that are in the mountainous West rely on snowmelt for both water and hydro-electric power. I think this is something that a lot of Easterners don't have a good handle on. Without dams on all of the major western rivers, the American West couldn't exist as we know it, because it simply doesn't receive enough consistent precipitation. Most of the West's precipitation falls as snow in the winter, which then becomes the snowmelt run-off in the spring. We've built a lot of dams so that we can store than run-off and let it through gradually throughout the year, instead of just watching it thunder by for a month every spring. So if the climate changes enough that it stops snowing in the West as much as it used to, then the West is going to have a major problem. Because, among other things, dams require a certain base-level amount of water to continue being effective: not just for hydro-electric power, but because of the amount of silt that accumulates if there isn't enough water moving through them (I think). Anyway, there are a couple of major reservoirs in the Southwest, like Lake Powell, that are already pretty close to reaching the level of un-usability because of the persistent drought or semi-drought conditions in the Southwest.

And, finally, there are already problems with how the precious river water/snowmelt is divied up in the West. The Colorado River compact is a good example of this problem: seven western American states decided to divy up the water from the Colorado River between them in 1922. According to agreements signed with Mexico, they also had to budget for a certain amount of water that would be allowed to flow across the border. For reasons I will never understand, the people in charge of calculating the average flow of the Colorado River only looked at a few years worth of data, which happened to be particularly wet years, and decided that the average flow of the Colorado River was actually a lot higher than it is in normal conditions. So they wrote up the agreement, only to discover a couple of years later that they'd alloted more water than actually existed. As it stands, Arizona doesn't use all of its allotment, which allows California to use more than it is officially allowed. And the water is so full of chemicals and pesticides (because it gets used and re-used so often and the river winds mostly through serious desert country) by the time it gets to Mexico, that the U.S. had to build Mexico a de-salinization plant just across the border to make the water from the Colorado usable.

All of this means, that although the continent itself is not going to "run out of water" I think it is pretty reasonable to assume that there are going to be struggles over water in the next 50 years, as cities in the West fight for their right to survive. If you're living in the humid East or the South, you might not notice it much. But I do think that something's got to give in the West eventually, and when it does, I think we'll see the re-concentration of the population in a couple of Western urban centers, and I think a lot of the mid-size cities will fade when they lose the water battles, which will force a lot of people to move back to areas where water is a more intrinsic part of the landscape.
posted by colfax at 3:30 AM on July 10, 2012 [13 favorites]


Erm, correction: we started tapping the Ogallala Aquifer in the 40s, I think, which means it was longer than 30 years ago. But the point still stands that the people tapping it have never been planning on using it in a long-term sustainable way, which means at some point, the usable water in it is going to run out.
posted by colfax at 3:59 AM on July 10, 2012


I live in Central Florida. At first glance, it seems like we have lots of fresh water - but in reality, we have a problem. There are people who predict that many towns around here will have to institute a "toilet to tap" policy to have enough water within the next 30 years. That means that toilet water is filtered, and returned back to tap water in kitchens.
posted by Flood at 4:31 AM on July 10, 2012


A historical note: there was a civilization in the Sahara called the Garamantes who the Romans interacted with. They dug deep wells to get water in the desert and are "believed to have marked the first time in history when a riverless area of a major desert was settled by a complex urban society which planned its towns and imported luxury goods." The current theory of the researchers studying them seems to be that their settlements disappeared after a combination of depletion and a change in the North African climate wiped out the water supply.
posted by XMLicious at 5:10 AM on July 10, 2012 [1 favorite]


Yeah, it depends on the area - there are chunks of Texas where most of the water in the rivers is treated wastewater. Not the worst thing, really, we do a Pretty Good job of treating wastewater. But as more people then use resources that are largely treated wastewater for their municipal water, it drives up the cost of treatment.

Americans are still Incredibly wasteful with water compared to other places. There are huge efficiency gains still yet to be had, but as many have noted, the biggest efficiencies will come from irrigation and industrial uses.

There's a long and storied history here and elsewhere of people fighting over water - from plans to pipe the Great Lakes' water over the Rockies to the Three Gorges Dam. If you're interested, there are some great books on the subject.

For most of the US, though - your drinking water, if it's municipal, is incredibly safe and cheap well regulated. Don't waste it, but don't sweat it, either.
posted by ldthomps at 6:28 AM on July 10, 2012


According to the USGS, "public supply," i.e. drinking water, only counts for about 18% of the total daily draw. Irrigation is more than three times that.

There is definitely going to be fresh water to be had. The real question is how much it's going to cost. If we have to transport it any appreciable distance, this is going to be expensive, because water is heavy. But pollution will also be a cost driver, as filtering and purifying water is also expensive.

We'll wind up doing it regardless, but it may get to be pretty pricey. Water costs are kind of like energy costs: increases there are carried all the way down the line.
posted by valkyryn at 6:52 AM on July 10, 2012


There are people who predict that many towns around here will have to institute a "toilet to tap" policy to have enough water within the next 30 years. That means that toilet water is filtered, and returned back to tap water in kitchens.

The problem with "toilet to tap" is birth control pills. Women who take the pill excrete certain hormone analogs in their urine, which ends up in the sewage. The treatment process which converts sewage back to potable water does remove harmful bacteria etc but it doesn't remove those hormones.

They're not present in very great quantities, but when it comes to continual exposure to hormones they don't have to be, and they would affect everyone. Girls would start blooming earlier, for example. But the biggest problem would be effects on men, and even more so on boys.

Until someone can come up with an effective way to remove those hormones, you won't see widespread adoption of "toilet to tap" reprocessing. Ocean desalinization is more likely; the only issue there is that it uses a huge amount of energy, so it will cost a lot. That's probably what's going to happen with the Colorado: a greater percentage of the water will go to Arizona and New Mexico, and Los Angeles and San Diego will start relying on desalinization of ocean water.
posted by Chocolate Pickle at 7:39 AM on July 10, 2012 [1 favorite]


Two thirds of the surface of the world is covered in water. We won't run out. We will face challenges in making sure water gets used wisely. It will require us to change and do things differently. It will involve expense.

IIRC, earthships can supply household water for the year with as little as ten inches of rain per year. There are very few places in North America which don't get at least that much rain. (I think average rainfall is about 30 or 40 inches per year. I have lived in places that were considered "arid" and had twenty inches per year.) Areas which are currently viewed as "unsustainable" could become sustainable by adopting more grey water reuse, local rain water capture and other principles used by earthships.

Most folks are slow to adapt to change. People tend to have to be in a lot of pain to change. If we were more proactive, this could be a lot less painful than it is likely to wind up being. In shir, if some locales run out, it will partly be their own fault.
posted by Michele in California at 11:34 AM on July 10, 2012


The problem with "toilet to tap" is birth control pills.

And heavy metals and pesticides and herbicides and antibiotics and antidepressants and nanoparticles.

Pick your poison.
posted by BlueHorse at 4:47 PM on July 10, 2012 [1 favorite]


All of the questions you mentioned and a lot brought up in this thread are addressed in the really really good book The Big Thirst: the secret life and turbulent future of water. It just came out this year and I'm only half-way through it but it totally addresses what you're asking about. The short answer is: we're going to have be smarter about how we distribute and consume water and what needs get privileged (farming, housing, or microchip plants?) but water is not a consumable resource and if we can adapt our consumption we will be okay.
posted by librarylis at 9:50 PM on July 10, 2012


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