The Slow Death of Water

Running out of water is not an event.

Before the pump, none of these systems could be over-drawn.

The usual account makes Yemen seem simply careless with its water. The opposite is the case. On the mountainsides, farmers built stone terraces in their thousands. Some highland systems were first laid in the Bronze Age and are still in use. In the wadis, they practised spate irrigation, diverting the brief, violent floods that follow a storm across fields prepared to receive them.

All these systems share a design principle: each can use only water that has recently fallen from the sky. A flood cannot be over-drawn. The rules that governed them, upstream before downstream and ancient rights before new ones, were enforced by communities that all drew on the same visible source. They could see at once when a neighbour took more than his share.

The well was, for each farmer, an entirely rational decision.

In the 1970s and 1980s, Yemeni men worked in the Gulf in very large numbers and sent billions of dollars home. Some of that money bought a diesel pump and a borehole. This is the hinge of the whole account, and it is worth stating plainly: for an individual farmer, the well was an unambiguously good decision. It freed him from waiting for rain that might not come, allowed him to grow a cash crop rather than subsistence grain, and made his family more secure.

The resource he drew on, however, was shared and invisible. The customary rules worked precisely because everyone could see the same source, so they had nothing to say about it. What followed is the most familiar sequence in groundwater management and one of the hardest to arrest. As the water table falls, shallow wells fail. Those who can afford to drill deeper keep their water; those who cannot lose theirs. Depth becomes a proxy for wealth. Each new deep well lowers the table further, making it more necessary, rather than less, to drill deeper.

The first two figures are water-table depths; the rest are drilling depths reported in 2010 by the World Bank-funded Sanaa Basin Water Management Project. Individual wells vary widely.

Qat pays every week of the year, and grows where water must be lifted.

Yemen has known for fourteen centuries what happens when the institutions fail.

East of Sanaa stand the remains of the Great Dam of Marib. Inscriptions credit Sabaean rulers with building it across Wadi Adhanah in the seventh century BCE. It was breached and repaired in 450, and again in 542. Around 570 CE, it broke for the last time. The irrigated land reverted to desert, and many of its people moved away, an event the Qur’an itself recalls.

The water did not disappear first. The capacity to manage it did.

• 7th c. BCE

  The Great Dam of Marib

  Sabaean rulers dam Wadi Adhanah. Its branching canals water the fields of a kingdom wealthy enough to dominate South Arabia.

• c. 570 CE

  The dam fails for the last time

  After breaches repaired in 450 and 542, the structure gives way for good. The irrigated land reverts to desert.

• Bronze Age on

  Terraces and spate irrigation

  Mountain terracing and wadi flood-spreading, governed by detailed customary water law, sustain rural populations on rainfall and floods alone.

• 1970s

  Remittances and rigs

  Money sent home from the Gulf, heavily subsidised diesel and new drilling rigs put a private well within reach of an ordinary farmer.

• 1980s–90s

  The drilling boom

  Groundwater use outruns customary control. The area under qat more than triples in twenty-five years.

• 2000s

  The warnings become explicit

  The Sanaa basin yields about 200 million cubic metres a year against an input of roughly 50 million, and experts warn the capital could run short by 2017.

• 2015

  War

  Fuel scarcity cripples pumping and power. Across sixteen cities, 38 per cent of water and sanitation assets are damaged, and civil servants’ salaries fall years into arrears.

• 2016–21

  Cholera

  The largest cholera outbreak of its time: more than 2.5 million suspected cases.

• 2019–26

  The need does not recede

  The UN counted 17.8 million people without adequate water, sanitation and hygiene in 2019. In June 2026, 14.4 million still required humanitarian assistance with them.

The war did not cause the crisis. It removed every remaining buffer.

Solar pumping removed the last thing limiting extraction.

When fuel for pumps became scarce and expensive after 2015, Yemeni farmers did something genuinely impressive: they turned to the sun. Markets for panels boomed, and solar pumping spread across the farms that could afford it. By every ordinary measure, this is good news. It is clean, resilient, and works when the fuel convoys do not. It has kept water flowing through a war.

A diesel pump meters itself: every hour of running costs money, so every farmer has a reason to stop. A solar pump, once installed, costs essentially nothing to operate, so the rational thing is to run it whenever the sun is up.

Without the discipline of a fuel bill, solar pumping can exceed what diesel ever extracted, and local authorities do not regulate it. Yemen has therefore replaced a dirty constraint with a clean absence of one.

It would be dishonest to end with an optimistic flourish. Groundwater is being drawn at more than twice the rate at which it refills, in a country with no money, public institutions that can no longer deliver services, and an unfinished war. But the picture is not uniform. Terrace rehabilitation restores rainwater capture and is labour-intensive, which, in a collapsed economy, is a feature rather than a cost. Spate irrigation still functions in the wadis. Local water user associations have taken over the running of schemes that the state no longer reaches.

The uncomfortable conclusion is that Yemen’s water problem is not, at root, hydrological. The country knew how to manage scarce water and did so for thousands of years, and the physical evidence of that knowledge still stands on every mountainside. What broke was the link between the rules and the resource, when a technology arrived that allowed individuals to reach water that no rule covered.