Hey everyone, welcome back to My Weird Prompts. I am Corn, and I am sitting here in our living room in Jerusalem with my brother. It is a beautiful afternoon here in February of twenty twenty six. The winter rains have been decent this year, but as anyone who lives in this part of the world knows, you can never take a single drop for granted.
Herman Poppleberry here. It is good to be back at the microphones. And you are right, Corn. Looking out at the Judean hills today, it is easy to forget just how much of a miracle it is that we have green space and lush agriculture in this part of the world. If you look at old photos from a hundred years ago, these hills were largely barren. Today’s prompt from Daniel is about exactly that. He wants us to dive into the two pillars of Israeli water technology that have essentially hacked the desert: drip irrigation and desalination.
It really is a fascinating topic because it is one of those areas where the technology is so integrated into daily life here that you almost stop noticing it. You see the black tubes in every public park, you see the purple pipes in the fields, and you drink the water from the tap without thinking twice. But when you look at the metrics, it is actually staggering. We are talking about a country that is sixty percent desert, yet it has a water surplus. In a world facing a massive climate crisis, that does not happen by accident.
It is a great prompt because Daniel hit on the two main drivers, but there is actually a third one—wastewater reuse—that completes the circle. He mentioned that we have a drip system on our own balcony, which we do, though I think our herbs are currently fighting a losing battle against the Jerusalem wind. But on a national scale, it is what allows those vineyards in the Negev and the date plantations in the Arava to exist. So, Corn, let us start there. For anyone who has only ever used a garden hose or a sprinkler, what is drip irrigation actually doing differently?
Right, because to the uninitiated, it just looks like a plastic hose with some leaks in it. But it is much more than that.
The best way to think about drip irrigation is as a shift from broad-spectrum flooding to precision delivery. If you look at traditional agriculture, for thousands of years, we used flood irrigation or sprinklers. You basically throw a ton of water at a field and hope the roots soak up enough before the sun bakes it off. In a climate like ours, where the evaporation rate is incredibly high, that is wildly inefficient. You lose a huge percentage of that water to the air before it even touches a root. Plus, when you soak the entire surface of the soil, you are watering the weeds in between the crops, which just creates more work for the farmer.
It is like trying to feed a baby by throwing a bucket of milk at its face and hoping some gets in its mouth.
That is a vivid, if slightly messy, analogy. Exactly. Drip irrigation, which was really perfected here in the nineteen sixties by an engineer named Simcha Blass and his son Yeshayahu, flipped the script. The story is legendary in the tech world here. Blass noticed a tree growing much larger than its neighbors because a nearby pipe had a tiny leak that was constantly dripping water right at its base. He realized that a slow, steady, localized release of water was far more effective than a massive drenching. But the challenge was how to do that over miles of pipe without the holes getting clogged or the pressure dropping.
So the actual tech is in the emitters, right? It is not just a pipe with holes in it.
That is the key distinction. If you just poke holes in a hose, the water pressure will be high at the start and nonexistent at the end. Blass developed these sophisticated plastic emitters that use friction and narrow, labyrinth-like pathways to regulate the flow. It creates a constant, low-pressure drip regardless of where the plant is on the line. This means you can deliver water directly to the root zone of the plant, minute by minute, hour by hour. Today, companies like Netafim—which is now a multi-billion dollar global giant—have taken this to the next level. We are talking about pressure-compensating emitters that can work on steep hillsides and self-cleaning mechanisms that prevent clogs from minerals or algae.
And because it is right at the roots, you are not wetting the leaves, which I know can cause fungal issues, and you are not losing water to evaporation. How much water are we actually talking about saving?
On average, drip irrigation is about ninety percent efficient. Compare that to traditional sprinkler systems, which are often around sixty to seventy percent efficient, or flood irrigation, which can be as low as forty percent. When you scale that to thousands of acres of desert, you are talking about saving billions of liters of water. But it is not just about saving water; it is about crop yield. Because the plant is never stressed—it is not waiting for the next big rain or the next time the farmer turns on the pump—it grows faster and produces more.
It is like a constant intravenous drip of nutrients and water for the plant. I have seen some of these systems where they actually mix the fertilizer directly into the water, right? Fertigation?
Fertigation, exactly. It is the ultimate control. You are feeding the plant exactly what it needs, exactly when it needs it. And in twenty twenty six, this has become "Smart Drip." Farmers now use soil sensors that measure moisture levels in real-time and satellite imagery that tells them exactly which part of a field needs more water. The system can automatically adjust the flow based on the weather forecast. It turned the Arava desert and the Negev from places where nothing could grow into some of the most productive agricultural land in the region. We are talking about cherry tomatoes, peppers, and even grapes for world-class wine, all grown in sand.
It is fascinating. But even with the most efficient irrigation in the world, you still need the water to begin with. And that brings us to the second half of Daniel’s prompt: desalination. Israel is famous for this. I remember growing up and hearing about the water crisis every summer, the level of the Sea of Galilee dropping, the red lines on the news. There was this famous ad campaign with celebrities whose skin would crack like the desert floor to remind us to save water. And then, almost suddenly, that conversation stopped.
It was a massive strategic pivot. For decades, Israel relied on the National Water Carrier, which pumped water from the north—the Sea of Galilee—to the south. But as the population grew and droughts became more frequent due to climate change, it simply was not enough. The government decided to go all-in on desalination in the early two thousands. Today, we have five major plants along the coast—Ashkelon, Ashdod, Palmachim, Hadera, and Sorek—with more, like Sorek Two, coming online or expanding. These plants provide over eighty percent of Israel’s domestic water. That is essentially all the water coming out of your tap in Tel Aviv or Jerusalem.
Which is wild to think about. We are basically drinking the Mediterranean Sea. Daniel asked specifically about the process: how does reverse osmosis work? Most people have heard the term, but the "reverse" part is what usually trips people up.
Right, so to understand reverse osmosis, you first have to understand regular osmosis. In nature, if you have a semi-permeable membrane—think of it like a very fine filter—with salty water on one side and fresh water on the other, the fresh water will naturally migrate toward the salty side to try and equalize the concentration. That is osmosis. It is a passive process.
It is trying to find a balance.
Exactly. Now, to get fresh water out of the sea, we have to fight that natural urge. We apply a massive amount of pressure to the salty side—we are talking about seventy to eighty bars of pressure—forcing the water molecules through the membrane while leaving the salt, minerals, and impurities behind. That is why it is "reverse" osmosis. We are using energy to push water against its natural gradient.
I imagine that membrane has to be incredibly sophisticated. We are talking about filtering out individual salt ions, right?
It is microscopic. The pores in a reverse osmosis membrane are about zero point one nanometers wide. For context, a human hair is about eighty thousand nanometers wide. These membranes are designed to let water molecules through but block almost everything else: salt, bacteria, viruses, even most chemicals. The challenge is that these membranes are delicate. If you just pump raw seawater into them, they will clog instantly with sand, shells, and seaweed. So, a desalination plant is actually a massive pre-treatment facility. The water goes through layers of gravel, sand, and anthracite filters before it ever touches the reverse osmosis membranes.
And what happens to all the stuff that gets left behind? You have this highly concentrated brine.
That is one of the big environmental challenges. You end up with a waste product that is twice as salty as the ocean. If you just dump it back at the shoreline, you could kill the local ecosystem because the brine is denser than seawater and sinks to the bottom, creating "dead zones." To solve this, these plants have massive outfall pipes that carry the brine several kilometers out into the sea. They use specialized diffusers that spray the brine into the currents to mix it back into the water column as quickly as possible. Researchers are constantly monitoring the seabed to make sure the salinity levels stay within a safe range.
You mentioned the energy cost earlier. Pumping water through those tiny filters at high pressure must take a lot of power. Is that the main bottleneck for other countries trying to do this?
Absolutely. Desalination is energy-intensive. It used to be prohibitively expensive. But Israel’s innovation wasn't just in the filtering; it was in the efficiency of the plants. The Sorek plant, for example, which was a landmark when it opened, uses huge sixteen-inch membranes instead of the standard eight-inch ones, which allows for more throughput in a smaller footprint. They also use energy recovery devices. These are brilliant—they capture the high pressure from the waste brine as it leaves the system and use it to help pump the incoming seawater. It is like a turbocharger for a car. You are recycling the mechanical energy.
So they are recycling the energy within the system itself.
Exactly. Because of those efficiencies, the cost of desalinated water in Israel has dropped significantly. We are talking about sixty to seventy cents per cubic meter. That is a thousand liters of high-quality drinking water for less than the price of a cup of coffee. When you compare that to the cost of a permanent drought or the political instability that comes from water scarcity, it is a bargain. In fact, Israel is now so good at this that we have started the "Reverse Water Carrier" project. Instead of just taking water from the Sea of Galilee, we are now pumping desalinated water into the lake during dry years to keep its levels stable and protect the ecosystem.
That is a complete reversal of the last fifty years of history. It really changes the geopolitics of the region, too. Water becomes a commodity you can trade or share rather than something you have to fight over. But there is a third part to this story that Daniel brought up, which is arguably even more impressive than the desalination: the wastewater reuse. He mentioned that Israel reuses eighty to ninety percent of its wastewater. To put that in perspective, the next closest country is Spain, which reuses about twenty-five percent. The United States is somewhere around five to ten percent.
It is a staggering lead. This is really the unsung hero of the Israeli water miracle. When we talk about desalination, we are talking about creating "new" water. But wastewater reuse is about getting a second and third life out of every drop. If we didn't do this, we would need twice as many desalination plants, which would be an environmental and financial nightmare.
Daniel asked if the treatment process for wastewater is different than the one for drinking water. I think a lot of people have a "yuck" factor when they hear about recycled water. Are we drinking the treated sewage?
In Israel, the answer is generally no, not directly. We use what is called a "dual-track" system. The water we drink is either desalinated seawater or groundwater. Once that water goes down the drain or the toilet, it travels to a massive treatment facility like the Shafdan, which is located just south of Tel Aviv in the sands of Rishon LeZion.
I have driven past that. It is huge, but it is surprisingly well-hidden behind the dunes.
It is the largest of its kind in the region, treating the sewage of the entire Tel Aviv metropolitan area. The treatment happens in stages. First, you have mechanical filtering to get the big stuff out. Then you have biological treatment in massive tanks where they use bacteria to break down the organic matter. But the real "secret sauce" in Israel is what happens next. In the Shafdan, they take that treated effluent and pump it deep into the ground, into a natural sandy aquifer.
So they are using the earth itself as a filter.
Precisely. It is called Soil Aquifer Treatment, or SAT. The water sits in the ground for six months to a year. As it moves through the sand and soil, it undergoes natural filtration and chemical processes that remove almost all remaining contaminants, including hormones and pharmaceuticals that traditional treatment plants often miss. By the time they pump it back up, it is essentially high-quality water, but it is designated specifically for agriculture.
And that is where the "purple pipes" come in?
Exactly. If you drive around the country, especially in the south, you will see these bright purple pipes in the fields. That is the universal code for recycled water. It is not for drinking, but it is perfectly safe for crops. Because it has gone through that soil treatment, it can even be used for crops that are eaten raw, like tomatoes or peppers. The farmers love it because it is cheaper than fresh water and it actually contains some residual nutrients like nitrogen and phosphorus that act as a natural fertilizer.
So, we have this closed loop. We desalinate the water from the sea, we drink it, we flush it, we treat it, we filter it through the sand, and then we send it to the Negev to grow the cherry tomatoes that end up back on our dinner table.
It is a near-perfect circle. And think about the economics of that. If we weren't reusing that water, we would have to desalinate twice as much to meet the needs of our farmers. The cost of agriculture would skyrocket. Without that eighty-to-ninety percent reuse rate, farming in the desert would be a luxury we couldn't afford. It also solves a massive environmental problem. If you are not reusing that wastewater, where is it going? Usually, it is being dumped into the ocean or rivers, which causes massive algae blooms and pollution. By sending it to the farms, you are keeping the Mediterranean clean and turning a waste product into a valuable resource.
It is a total shift in mindset. Daniel mentioned the "symbiosis" between these technologies. It seems like they really do rely on each other.
They do. And there is a technical detail here that is really cool. Desalinated water is actually too pure. Because reverse osmosis is so effective, it removes minerals that humans and plants actually need, like magnesium. In fact, there have been health studies in Israel about the need to add magnesium back into the drinking water because we rely so heavily on desalinated sources. But when that water goes through the human system and then into the wastewater treatment process, it actually picks up some of the minerals and organic complexity that plants crave.
That is an interesting irony. The "pure" water is for us, and the "enriched" water is for the plants.
Exactly. And because drip irrigation is so precise, it is the perfect delivery mechanism for this recycled water. You wouldn't want to use a giant sprinkler to spray recycled water all over a field; you might have issues with aerosols or uneven distribution. But with a drip line, you are putting that recycled water directly into the soil, where the plant can use it immediately. It is the ultimate tech stack for a water-scarce world.
I think there is a broader lesson here about how we think about "sustainable" technology. Daniel pointed out that Israel’s solar adoption isn't as high as it could be, which is true—we are still very reliant on natural gas from the offshore fields. But when it came to water, it wasn't just a matter of "wouldn't this be nice for the environment?" It was an existential necessity. If we didn't solve the water problem, the country simply couldn't function.
Necessity is the mother of invention, right? Israel didn't have a choice. In the nineteen fifties and sixties, the country was literally running out of water. That pressure forced a level of coordination between the government, the scientists, and the farmers that you rarely see in other sectors. They built a national water grid, they mandated low-flow toilets and showerheads decades before it was cool, and they invested in the research that led to Netafim and the large-scale reverse osmosis plants. It is a holistic approach. It is not just one "silver bullet" technology. It is the combination of infrastructure, regulation, and innovation.
I am curious, though, Herman—as the resident nerd here—what is the next frontier? If we have already mastered desalination and reuse, where does the tech go from here? We are sitting here in twenty twenty six, and the world is only getting thirstier.
There are two big challenges on the horizon. The first is the "Water-Energy Nexus." As we move away from fossil fuels, we need to find ways to power these massive desalination plants with renewable energy. The problem is that solar is intermittent, but a desalination plant needs to run twenty-four seven to be efficient. So, there is a lot of research into energy storage and "flexible" desalination—plants that can ramp up when the sun is shining and scale back when it is not. There is also the "Water-for-Energy" deal that has been in the works with Jordan and the UAE, where Jordan provides solar power to Israel, and Israel provides desalinated water to Jordan. It is a regional integration that would have been unthinkable twenty years ago.
Like a giant regional battery and tap.
Exactly. The second frontier is what they call "decentralized" water. Right now, our water system is very centralized—big plants, big pipes. But that is vulnerable to cyberattacks or physical damage. The next step is smaller, modular desalination and treatment units that can be used by a single neighborhood or a single farm. Imagine a shipping container that can turn brackish groundwater into drinking water using only the solar panels on its roof. We are already seeing this with companies like Watergen, which creates water out of thin air using atmospheric water generators. They are deploying these in disaster zones and remote villages in Africa.
That would be a game-changer for developing nations. It is taking the "drip irrigation" philosophy—precision and localization—and applying it to the water production itself.
Exactly. It is a shift from a "resource" mindset to an "infrastructure" mindset. It makes me think about how we treat other scarce resources. If we applied this level of circularity to plastic or rare earth metals, the world would look very different. The Israeli water model is essentially a proof of concept for a circular economy. It shows that you can take a region with almost no natural water and, through sheer technical will, create a surplus.
It is also a reminder that technology isn't just about the newest app or a faster processor. Sometimes, the most important technology is the stuff that allows us to eat, drink, and live in places where nature says we shouldn't. Looking at the vineyards in the Negev, it is easy to see the beauty, but it is important to remember the millions of lines of code, the thousands of high-pressure membranes, and the decades of engineering that make that beauty possible.
Well said. And it is a testament to the fact that humans can be incredibly creative when our backs are against the wall. We didn't just survive the desert; we figured out how to make it bloom. And now, we are exporting that knowledge to California, to India, to Australia—places that are facing the same challenges we faced fifty years ago.
And on that note, I think we have covered the lowdown on the water miracle. Daniel, thanks for the prompt—it is a topic that hits very close to home, literally. It makes me want to go out and check the emitters on our balcony herbs, though I suspect they need more than just water at this point.
They might need a miracle of their own, Corn. But definitely, it makes me appreciate that glass of water on my nightstand a little bit more. Every time you turn on the tap here, you are participating in a massive, high-tech symphony.
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Thanks again for joining us. This has been My Weird Prompts. I am Corn.
And I am Herman Poppleberry.
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Goodbye everyone.
