Yossi Yaacoby

Yossi Yaacoby did not change jobs so much as climb every rung of the same ladder. He trained as a chemical engineer at Ben-Gurion University, added an MBA, and then spent more than 25 years inside Mekorot, the company he calls “my home.” He started as a process engineer who, by his own admission, “didn’t understand what is a distillation,” moved into project management, became Mekorot’s head of innovation running its WaTech startup center, then chief of staff to the CEO, and is now Vice President of Engineering. As he puts it, he is “trying to get all the things that I learned all over the way and to implement it. By the way, I’m still learning.”

Mekorot is worth understanding before Yossi Yaacoby is, because the two are inseparable. Founded in 1937, twelve years before the State of Israel itself, Mekorot is the national water company that supplies roughly 80% of the country’s drinking water and moves more than 1.7 billion cubic metres of it a year through some 3,000 installations, while losing under 4% to leaks (a figure most utilities can only envy). It built the National Water Carrier that pipes water from the wetter north to the dry south, drilled wells 1,500 metres down, and turned to desalination and recycled wastewater when even that ran short. Israel now reuses close to 90% of its treated wastewater, a world record, most of it for farming.

Yossi Yaacoby’s distinctive argument is that the water industry keeps using the wrong word. “Some CEOs of water utility always speak about innovation,” he says, “but then when you are listening carefully, they are not speaking about innovation, they are speaking about resilience.” His point is that climate change has broken the old engineering math: the storm you used to design for once a century now shows up every five to twenty years, so chasing the single most extreme event bankrupts you. Instead he plans around what he will actually see, “150mm rainfall a day in Israel,” and treats the rest as risk management: take the hit for a few days, then recover. The goal he sets is blunt, to come back to “60 to 70 to 80 or 90% of capabilities within days, not weeks.”

Yossi Yaacoby has the kind of war story that makes the abstract concrete. On a single day in February 2023, three things hit Mekorot at once: an earthquake in Turkey and Syria knocked dozens of Israeli wells out of service with turbidity, the National Water Carrier was partly shut for its routine winter maintenance, and a sea storm (Storm Barbara) took down four of the five mega desalination plants that together supply about 60% of Israel’s daily drinking water. No wells, no main carrier, four of five desalination plants dark. Mekorot leaned on groundwater and the one plant still running, and was “overcoming this disaster” within 24 hours. That is what resilience means when it is not a slide in a conference deck.

“Some CEOs of water utility always speak about innovation, but then when you are listening carefully, they are not speaking about innovation. They are speaking about resilience.”

Yossi Yaacoby’s proudest piece of engineering is also the most literal expression of that mindset: the Fifth Line to Jerusalem, a roughly 13-kilometre tunnel that lifts desalinated seawater from the coast up to the mountains, the first time desalinated water ever reached the city, built to secure it for the next fifty years. He joined at the very end, “at the point when you are pushing the button and the water is flowing,” which, for an engineer who has spent his whole career making Israel’s water arrive on time, is about as good as it gets.