- Water is a crucial building block for life, for farming, for food, and for showers.

Often water comes from far away.

For example, over half of Southern California's water is pumped out of the Colorado River.

It is then transported up and over a mountain range to be used in cities and farms.

But as rainfall and temperatures change, scientists are seeing a megadrought emerging the American West.

And much of that long-term drought is centered right over the Colorado River.

Which means giant cities like LA and rural farms alike could see a strain on their water supply.

In this episode, we'll learn why this drought is so bad and find out what lessons we can learn from people who've lived in the Southwest for thousands of years.

(upbeat music) A drainage basin is an area where precipitation collects and runs into a particular body of water.

The basin in the Colorado River spans seven States and two countries.

40 million people count on its water.

But what happens when rivers dry up and the water you're counting on doesn't come?

To understand, I first asked water and drought scientist, Brad Udall, what's going on.

- In 2000 a drought began that now 20 years later is the most severe drought since gauges were installed on the river in 1906 in some places.

The flow is down about 20%.

- Drought is usually defined as a period of abnormally low rainfall leading to a shortage of water.

But Brad told me that this drought is a bit different.

That's because while rain is down, that doesn't fully account for the low water levels.

- We now actually have a new term for this, it's hot drought.

So higher temperatures dry out the earth.

And what we're finding is that higher temperatures lead to greater evaporation in all its forms.

And that evaporation is the cause of this decline in flow.

- In other words, as temperatures increase over time, the process of evaporation takes more water away from rivers, lakes and snow-capped mountains.

This helps explain why river flow in the Colorado basin is down 20% despite precipitation only being down by 5%.

And droughts do end, but according to many scientists waiting for rain in this case is probably not a good idea.

- The term "drought" implies some kind of return to normal at some point.

Drought implies temporary, and most scientists nowadays have started talking about the aridification of the West, meaning a more permanent move to a dry state.

(car engine roaring) - Few people understand the threat of drought better than Nancy Caywood.

She's a fifth generation farmer in Pinal County where water either comes from the Colorado River through the Central Arizona Project canal or from other rivers and canals in the Colorado basin.

This represents liquid gold.

This is our water supply right here.

We take it out, there's a gate right there and it goes down a little lateral canal that takes it right to our farm.

I'm gonna open up this gate, we have the gate open, we'll open four of them, allow the water to flow in.

We have about 135 acres of alfalfa.

- This is an example of flood irrigation, one of the oldest and most common irrigation methods which distributes water over the soil by allowing it to flow downhill with gravity.

There's a beautiful simplicity to it, but it's actually the least efficient way to irrigate as much of the water either evaporates away or seeps into the soil out of reach of the plants' roots.

And on top of that, alfalfa is a very thirsty crop, which means the beef that comes from the cattle it feeds is the highest water use food commonly available.

Drip and sprinkler irrigation can be much more efficient, but Nancy told us she's not been able to get the permits needed to change the irrigation style on the farm.

And the Caywood alfalfa fields are in good company.

60% of farmland in the Colorado basin is used to grow feed crops.

Combine all that demand, and here in Pinal County is where the drought hits home.

- The last time the reservoir was full was in 1992.

One year, we had nothing planted on this farm at all.

- In 2019 water in Lake Mead, the nation's largest reservoir, dropped so low it triggered the first cutbacks in water allocations ever in the basin.

Pinal County farmers were the first to have their water reduced, fields lay fallow, prepped and ready, but unplanted.

- This is a fallow field and we just didn't have enough water to plant it.

We have 120 acres of fallow land.

- Good news here is, since about 1980 American water use has actually gone down.

Even in growing American cities in the South West, total consumption has gone down despite pretty big increases in population.

But worldwide irrigated agriculture uses upwards of 70% of water in rivers and municipalities use much, much less, 20% or less.

- That's partially due to household water conservation efforts, but it's mainly due to the way cities and homes use water.

When you shower, wash dishes or even flush the toilet, that water is treated and returned to surface or groundwater rather than evaporating.

The same goes for some industrial uses.

But the largest opportunity and challenge to reduce water use is in the agricultural sector.

That's because water used for farming either becomes part of the growing plants or it's lost to evaporation, meaning it doesn't return to the hydrologic cycle for a very long time.

Scientists say this is the worst drought in 1200 years, but the Hopi you have lived in this area for over 2000 years and have grown food through it all.

We met up with Max Taylor, a Hopi Water Resources technician to find out if lessons from one of the oldest communities in the United States can be applied to modern life in the drying Colorado basin.

- The Hopi's been known to use the least amount of water.

Than people throughout the whole United States, it's just because we live in the desert, here we are more aware of how much you use.

And so the use is very little.

So we're down at my field.

This is my blue corn, they're planted here.

All of these are dry farmed.

I don't do any irrigation.

And the technique we use is you clear off an area.

You'll dig a hole down about maybe eight to 10 inches deep, get maybe eight or 10 kernels of corn and toss in there.

The wet moisture that you've taken up, you push them back in, then you cover it with dry soil.

And that's dry farming.

- His garden is planted in a low lying area to collect the little moisture that falls each year.

And his crops are extremely adapted to the region.

They're planted far apart to avoid competition for water, and they grow very deep roots that tap into groundwater.

- Right now we're in September.

You can still feel a little bit of moisture in the ground, see that?

Not much, but just enough that it's still keeping them going.

- Amazingly Max uses seeds for his own farming consumption that produces crops in what seems like dust with no irrigation.

He's never watered this field.

We have seeds that are being passed on from generation to generation.

So they're adapted to this dry climate.

The corn's been with the Hopi at least several thousand years.

I think the lesson to learn is that you have to live within your environment.

And I think that's how the natives have survived in these areas because they were sustainable.

And we know this country.

- Shifting towards crops appropriate for and adapted to their environment provides a vast opportunity for water conservation.

That shift can happen on farms or in cities when we choose to eat foods that need less water to grow.

On paper, a shift from feed crops and cattle makes sense.

But if we wanna adapt to our warming climate in an equitable way, we can't write off farmers like Nancy and the families that have fed us for generations.

We would like to continue farming.

We don't plan on giving up this farm.

We are looking into alternatives, we're looking into alternative crops, we're looking at water conservation irrigation techniques.

Alfalfa takes seven to nine acre feet of water a year to grow it.

Olives would take about one and a half acre feet of water.

But if we were to get into say olives, there'd be a lot of soil preparation.

So it costs us a lot money to get started.

- But the question is, can we come together as a country and implement techniques to reduce the strain on our water supply before they're even more shortages?

- We need to be ready for some really big changes coming at us that are frankly outside of our comprehension.

This is how we make the best out of a bad situation and stand by those who end up facing the biggest changes and challenges.

And while we focus on the American Southwest in this episode, drought does affect almost every part of the country.

So practicing water conservation as a part of your daily life can help you prepare for when water supplies run low in your region.

Some of the most effective things you can do today are not that hard.

For example, never leave a faucet running when it's not being used, like when brushing your teeth or washing dishes.

Make sure to fix leaky faucets and choose energy and water efficient appliances.

If you want to get more involved, you can place a brick in the tank of your toilet so it uses less water for each flush, or convert your lawn to a beautiful landscape that doesn't need irrigation.

Or even install a rainwater catchment system.

Of course, there's another thing we can all do, and that's to fight the underlying cause of this drought, climate change.

The future of this drought is unwritten and the less warming we create the brighter our water future will be.

(soft music)