Editor’s note: Marshall Brain – futurist, inventor, NCSU professor, writer and creator of “How Stuff Works” is a contributor to WRAL TechWire.  Brain takes a serious as well as entertaining look at a world of possibilities for Earth and the human race.  He’s also author of “The Doomsday Book: The Science Behind Humanity’s Greatest Threats.” Brain has written several posts recently about the threat of climate change. His exclusive columns written for TechWire are published on Fridays.

+++

RALEIGH – It is impossible to miss all the headlines talking about the water crisis happening (and worsening) in the American Southwest. Here are five of the more alarming:

This is a doomsday scenario affecting tens of millions of people. Lake Mead supplies their drinking water and has traditionally been a source of electricity for cities like Las Vegas.

In California, with a population of 39 million people, the problem has the potential of becoming especially dire. The governor, Gavin Newsom, recently announced a $8 billion spending package which attacks California’s water scarcity problems from four different angles:

  1. 260 billion gallons of water created through recycling
  2. 160 billion gallons of water saved through conservation efforts
  3. 3 trillion gallons of new storage space (e.g. lakes) so when there is a big storm there is a place to put the water
  4. New desalination plants

The federal government is also adding billions of dollars more through spending in the Inflation Reduction Act.

It is an enormous amount of money to spend on California’s water scarcity problem. But what if all of these billions of dollars are ignoring the elephant in the room? What if there are several easy solutions that could save trillions of gallons of water per year?

In order to talk about the elephant, we need to understand how much water people in a city like Los Angeles use.

Understanding Water Use in Los Angeles

Think about the City of Los Angeles. It is a huge, sprawling metropolis; the second largest metro area in the United States behind New York city. There is the official city Los Angeles, with 4 million people. Then there is Los Angeles County with a population of 10 million people. And then there is the greater Los Angeles metro area with a population 18.5 million people. This is the 5-county region including Los Angeles County and adding in Orange, Riverside, San Bernadino and Ventura counties.

In round numbers, about half of California’s total population of 39 million people lives in the Greater Los Angeles area. And 5.6% of all of the people in the United States live in this area. It is a huge number of people compressed into a land area of about 2,300 square miles.

How much water do all of these people use? On average they are using about 130 gallons per person per day. If you have never seen it before, this might seem like a big number. But this is completely normal for the average American. It includes all of the water for drinking, showering, cooking, dishwashing, clothes washing, car washing, toilet flushing, garden watering and everything else. So how much water do all of the people in the greater Los Angeles area need? On a daily basis is it:

18,500,000 * 130 = 2.4 billion gallons per day

On an annual basis the 18.5 million people in the greater Los Angeles need nearly one trillion gallons of water.

Where does this water come from? The Los Angeles Department of Water and Power is a water supplier for a portion of this population, and their water comes from these sources:

  • 45% from the California Aqueduct, which brings water down from the San Francisco bay area
  • 34% from the Los Angeles Aqueduct, which brings in water from the eastern Sierra Nevada Mountain area
  • 8% from the Colorado River Aqueduct, which is bringing water from the Colorado river and therefore Lake Mead
  • 12% from local groundwater pumping
  • 1% from recycling

If all of these sources of water were to dry up, then Los Angeles has a fallback position. Los Angeles has the Pacific Ocean next door and many miles of coastline. The city could build desalination plants that use electricity and reverse osmosis filtering to turn seawater into fresh water. As described in this article, this option is completely feasible, but there are two problems: this desalinated water is expensive, and the brine can cause ecological impacts. Therefore, everyone’s water bill would go up and the environment would suffer. See this video for details – https://youtu.be/bfr82RB72U8?t=165

The Elephant in the Room when it Comes to California Water

But do Los Angeles (and other cities in California) need to go down the desalination path? This is where we get to the elephant in the room.

As we have seen above, people do use a lot of water in California. But there is another aspect to California that uses an incredible amount of water, and this is agriculture.

In particular, California is the home to an unbelievable number of almond trees. Let’s focus on this one crop that California produces, because it is so incredibly interesting. To get a sense of the size of the almond crop in California, try this:

  • Go to Google Maps
  • Turn on the satellite view
  • Take a look around the city of Wasco, California.
  • In particular, look to the right of the city and zoom in. You are going to see trees – thousands and thousands and thousands of nut trees in neat rows.
  • If you look around you will also see canals running through the area to bring in water.

Look all around Wasco, California – the number of trees growing here in what is approximately a desert area is impossible to believe. There are millions of nut trees in this region. See also this video:

It turns out that the world eats about 4 million tons of almonds per year, and about half of the world’s almonds come from California. Specifically, California is producing about 5.2 billion pounds of almonds per year on roughly one million acres (1,600 square miles) of California farmland.

A pound of almonds contains about 400 individual almonds. Therefore, in round numbers, there are roughly 2 trillion individual almonds being produced in California per year.

Why do we care that there are 2 trillion almonds produced in California per year? It’s because of this fun fact: each almond takes about a gallon of water to produce. Therefore, the state of California is using about 2 trillion gallons of water per year to produce this almond crop. The water comes in either through canals or by being pumped out of underground aquifers.

To put it another way, the almond crop in California – just this one crop – consumes about twice as much water as the 18.5 million people living in the Greater Los Angeles area.

Even more amazing is the fact that most of these almonds get exported to other countries. So we are taking this enormous amount of scarce water out of California and sending it across the world.

Let’s look at another example

It seems impossible that California is using trillions of gallons of water to produce its almond crop. Therefore, let’s look at another example. Watch a minute or two of this video:

What you see here is a farmer explaining how they flood-irrigate their hay fields. You see an absolutely enormous amount of water flowing onto these fields. So. Much. Water.

Then you look up this farm on Google Maps, and you realize it is just outside Phoenix, Arizona. This is a straight up desert area of the United States. And they are using millions of gallons of water to grow hay here. It seems absolutely impossible, yet this kind of thing is happening all across the Southwestern United States. The water for the canal in this video would be flowing in the Gila river if it were not flooding this hay field. And the Gila river would join the Colorado river, giving it that much more water for people downstream.

What if the world gave up Almonds?

Now we as human beings can step back from all of this information and, if we are rational people, we start asking questions. For example, if almonds require so much water, and water is becoming so scarce in places like California, does the world actually need almonds from California? What if we made almonds in California extinct?

Or to put it another way: What if we banned almond trees in California and freed up two trillion gallons of water? This water would either stay underground, where it is desperately needed to prevent subsidence and falling water tables, or it could stay in rivers so that the rivers are not sucking our reservoirs like Lake Mead dry.

If you do not like the idea of banning things, what if we set the price of water for farmers at 5 cents a gallon? Then a pound of almonds would contain $20 worth of water, and economic forces would naturally reduce demand for almonds. Many of the farms would close due to lack of demand and the problem would solve itself.

What if we stopped growing crops like hay and alfalfa in the desert and freed up all of that water too? We could do it either by banning the crops or by raising the price of the water to 5 cents a gallon. This video demonstrates the problem.

What if we looked at other crops? For example, California produces many of the salad vegetables like lettuce and tomatoes in the United States. Does it make sense to grow these crops in open fields in an arid place like California? Probably not. What if instead we started growing crops like these in vertical farms near the people who eat them? This is exactly what has happened in Dubai this year:

The World’s Biggest Vertical Farm Just Opened in Dubai

“The Dubai facility has the capacity to produce over two million pounds of leafy greens annually, and will grow lettuces, arugula, mixed salad greens, and spinach… that means vertical farms could use energy from solar panels to grow food indoors using 95 percent less water than traditional agriculture. ECO 1’s location just outside Dubai follows the trend of most vertical farms being near big cities.”

See this video for a look inside the facility:

The point is, we are at the point where we are about to suck our reservoirs like Lake Mead (and many others) down to dead pool status. We are sucking our underground aquifers dry as well. We don’t need to do this. There are easy solutions to these problems if we think about them rationally. Either start banning irrational crops in arid regions where water is scarce, or raise the price of water so that growing the crops in arid regions no longer makes economic sense. Either way, we can start to gain control of the water scarcity problems we see in the American Southwest.

Sources