[intro plays]

Sabrina: Last time we talked, things got a little heated, so let's try to cool things off. We were talking about waters, specifically about what happens to people when this crucial resource becomes scarce. Scarcity leads to cutting back, conflict, and some seriously difficult decisions. It's a big problem, no doubt, but it's also an opportunity, because scarcity inspires people to come up with creative solutions. Water is in short supply in California these days, but that's not the only place that has to deal with this problem. So how have people dealt with the scarcity of water in other places, and at other times?

[Text: Big Question]

Maybe there's a lesson from ancient people, other countries, or even from astronauts that can help California out. Even though all of these people have the same problem (not enough freshwater) they all dealt with the problem differently? Why? Because they all faced different kinds of challenges when it came to their water supply and had different resources available that they could use to fix the problem. So let's look at some ways people have dealt with the scarcity of water.

[Text: Investigation]

First we'll go back. Way back. A couple thousand years ago, to ancient Rome. The Romans built cities all over their empire and sometimes they didn't build those cities by a natural source of water like a river, but instead they stuck them in the middle of a dry plain. So how did those people get their water? Engineering. The Romans built long channels called aqueducts that flowed from springs in the mountains down to the city. The city of Rome itself was built on the Tiger River, but the city's water also came from aqueducts. That's because the Romans polluted the water so much with their waste that it was undrinkable. So clean water flowed from the mountains and their gross waste water got dumped in the river. Without aqueducts, Roman cities couldn't have had their public bath houses where people bathed, and most importantly, they wouldn't have had clean drinking water.

Now, other people have lived right on the water but they still didn't have anything to drink. It's that old paradox: you want a beautiful beach side villa, but you can't can't drink seawater. Or can you? Israel is a country on the Mediterranean sea and most of Israel's drinking water comes from the sea. How? Israel has a bunch of desalination plants. These factories remove the salt and other impurities from the saltwater, creating delicious clean drinking water. Now maybe you're wondering: If we know how to make saltwater drinkable, how could anyone possibly have a water problem? Well, there are drawbacks. The process of getting the salt and other impurities out of the water is very expensive and it requires a lot of energy, so in most cases, it's just not practical.

But if you want to know the coolest, most out-of-this-world way to reuse water, that's gotta be the astronaut way. Part of why we humans go through so much freshwater is just that we turn it into urine and sweat really quickly, which is a problem for astronauts because it's way too expensive and difficult to keep sending water up to the international space station. But when you think about it, pee, sweat, and dirty wash water are all still just water. Just very impure water. And we know that in nature, all water is recycled, so what do the astronauts do? They recycle their pee. Using a special set of filters, astronauts are able to recover 93% of the water that's in their urine and other used water. It's like a tiny water cycle up in space, recycling the same water particles every single day. This makes astronauts real pros at conservation: protecting the water they have. And even though the thought of drinking recycled pee might sound super mega gross, the water on the International Space Station is actually purer than the water that comes out of most faucets here on Earth. Not sounding so bad now, huh?

[text: Conclusion]

So maybe now we've got some new ideas for California. First, bring in water from other sources, like the Romans did. California's already doing that, it's cities rely on snow melt and river waters from other areas. But as the drought continues, this solution is becoming less and less sustainable. Water isn't being replenished fast enough so there simply isn't enough to go around.

There are also desalination plants turning seawater into drinking water. California is a coastal state after all and in fact California's already planning on building some of these desalination plants. But if California is much, much larger than Israel, so these factories won't be able to meet all of the state's enormous needs.

How about recycling? In California, a lot of waste water is already recycled for use on crops and lawns, but new plants have already been built that could help turn that used water into drinking water too. Scientists are also trying to engineer new crops or create new forms of farming that use less water. It's going to take a lot of innovation and teamwork to come up with a solution to California's water problem. But that's the beauty of difficult situations, we get an opportunity to come up with a solution, perhaps a solution that's even better than the system we had before. In the meantime, we can all help out. Take shorter showers, and turn the faucet off when we brush our teeth. In other words, you can be part of the solution.

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