This post is a thought experiment. Clearly, I’m missing some of the nuance around this issue. However, thinking about how to solve this was fun, and I think some of the below ideas could be useful.

Lately, there has been a loooot of fighting, politicizing and hand-wringing about the drought in California (see CA website). You know it’s been going on for a while when the state government has time to put a webpage up about it!

from MIT’s Technology Review

States measure water in acre-feet, where one acre-foot is the amount of water required to cover an area of one acre to a depth of one foot. One acre-foot is the equivalent of 326,000 gallons of water, or the average use of an American household per year.

Right now, California faces a shortage of roughly 6 million acre-feet. This shortage is due to a lack of rainfall and snowstorms that replenish California streams. To make up for this shortfall, California is tapping groundwater sources (called “aquifers”), drilling deep into the ground to reach non-renewable sources of water.

Scott from Slate Star Codex (one of my favorite blogs on the internet) wrote an excellent piece on the California water drought that’s well worth reading. In it, he pulled together the below infographic that shows where California’s 80million acre-feet of water goes each year:

As you can see, roughly 3.5% of all water usage comes from the 40 million citizens of California. This 2.8 million acre-feet includes every gallon of water used for laundry, toilets, showers and faucets by every person, every year.

Thus, if every person was to completely stop using water for an entire year, the state would still be short 3.2 million acre-feet.

Hmm. Unlikely the voters would pass this.

What about if people stopped watering their lawns? That’d save 3.8 million acre-feet of water per year, leaving “just” a 2.2 million acre-feet shortage.

This faces a similar problem: people won’t stop watering their lawns. And, to be fair, one person watering their lawn once a week doesn’t make much of a difference… but that individual decision, compounded 20 million times over, has a large impact on the California water shortage.

A California entirely run and inhabited by robots would only just have enough water in these drought conditions to continue agricultural and industrial production. That’s not a good sign for the 40 million Californians. So, what options do we have?

Potential Solutions

Before I talk about ideas for potential solutions, I’ll start by saying I will notrecommend anything that has to do with large-scale behavioral change or sweeping policy changes (like taxing or regulating water usage by big agriculture companies). In my opinion, both are unlikely to occur, so I’ll focus on technology solutions.

Idea #1: Raise the Price of Water

In several articles I’ve read online, commenters have said that simply creating a market around water prices would solve this issue. Raise the price, fewer people will use it, and bam: water crisis solved.

However, this article from Bloomberg tells a different story. Farmers in California — that group that uses 40%+ of California’s annual water — arealready paying 10x more for water than they were just a year or two ago. Yet, they keep using water.

Why?

From what I can tell, as a farmer you can’t just stop farming. “Not farming” is not an option. Farmers have already invested in the land, equipment, labor, and machines that make large-scale agriculture work — not farming means they make zero money.

So, what they do instead, in a world of 10x water prices, is plant less and charge more. The article mentions some farmers that can’t get water (or can’t afford it) are leaving large tracts of land unplanted to save money. At the same time, the cost of fruits, vegetables and nuts (of which California makes up half the US supply) is set to rise upwards of 6%.

One area where price increases could have an impact is on well water. Right now, well water — the water source that California is currently drilling dry — is priced as if it will never, ever run out, about 1/10th of a cent per gallon. See below graph for a cost comparison of different water sources (in non-drought conditions):

note: in current drought conditions, irrigation water (the main water source for agriculture) is priced 5–10x more than the $70 per acre-foot this chart suggests.

Under current regulations, groundwater (or well water) comes with land rights. If you own land that’s on top of a groundwater source, you can drill and tap it as much as you like: no restrictions. This has created a dynamic where those who own land with access to groundwater can take as much as they like and sell it to farmers who desperately need it.

So, we see prices going up but little impact on water usage by agriculture (who, if you remember, uses 34 million acre-feet per year). What are some other options?

Idea #2: Individual Water Restrictions

On individual, level, it’s hard to prevent people from using as much water as they want. And, as we’ve seen, if you cut each individual’s water consumption by 25% (installing more efficient toilets, cutting down on showers and water at restaurants, etc.), these rather inconvenient efforts still save only 0.7 million acre-feet. Put another way, by forcing multiple inconveniences on every individual in California, we can get about 11% of the way to closing the water shortage gap. Not very promising.

However, one area I think that’s ripe for potential improvements is in lawn care. You see, lawns are responsible for 3.8 million acres of water-feet usage each year — more than all human water consumption combined. This 3.8 million acre-feet represents 63% of the shortage California faces — fix this, and we’re a lot closer (and with a lot less personal inconvenience) to solving the problem.

Now, I’m not suggesting that we let every yard die and go brown. I lived in Las Vegas for a time, and that’s not a pretty sight. Plus, people want their lawns to look nice — it’s a human desire, on par with wanting to brush your teeth and shower to appear presentable. So, for the purposes of this thought experiment, I’ll assume it’s difficult to get people to stop watering their lawns.

No. Rather, than suggest that, I think there’s a way people can still get the green lawn look, but with much less water. Simply use a different kind of grass!

Most lawns in California use fescue grass, which requires “deep watering” 2–3 times per week.

After a bit of searching, I came across Enviroturf, a kind of grass that only requires deep watering once every 2 weeks.

What a beautiful, efficiently watered lawn.