Drip irrigation and the efficiency trap

Agriculture takes most of the region’s water: 92% of withdrawals in Iran, 88% in Morocco, 82% in Saudi Arabia and 79% in Egypt.¹ The region also gave the world its standard response. Modern drip irrigation was commercialised when Kibbutz Hatzerim founded Netafim in 1965 to develop Simcha Blass’s invention.² The uncomfortable science since then is that a more efficient field rarely means a basin that uses less water.

The numbers that sell the hardware

The field-level case is real. FAO’s training manual gives indicative field application efficiencies of 60% for surface irrigation, 75% for sprinklers and 90% for drip.⁵ Morocco promoted drip with subsidies as high as 100%, to raise productivity and rural incomes and to save more than a billion cubic metres of water.³

Those are design values. FAO’s own brief on Morocco adds that a growing number of studies find drip and sprinkler efficiencies can fall as low as gravity irrigation.⁶

The trap

The basin-level case is where the paradox lives. Water “lost” from a flooded field was never destroyed. Much of it drained back to the river or recharged the aquifer for the next user, and drip cuts those return flows.⁴ Grafton and colleagues, reviewing the evidence in Science, conclude that higher irrigation efficiency rarely delivers the presumed gain in water availability.⁷

Farmers then spend what they save, rationally enough. Molle and Tanouti found that in Morocco drip tends to bring denser planting, thirstier crops and the use of saved water to expand cultivated area, resulting in higher consumption.³ A satellite study of citrus in Tadla found only 1% difference in crop water use between drip and gravity plots.⁴

Morocco’s own institutions reached the same verdict. The Cour des comptes found that modernisation and drip promotion had not stabilised irrigation demand, and that groundwater overexploitation had worsened.⁸ The World Bank names the mechanism as Jevons’ paradox, with groundwater withdrawals 28% above renewable resources.⁹

The natural experiment

Morocco also ran the control. Satellite energy-balance studies found total water consumption in Tadla fell by around 15% between 2015 and 2021 after modernisation, while water productivity rose 47%. In Haouz, consumption stayed roughly constant. The World Bank attributes the difference to Tadla adopting a quota system for water allocation, which Haouz did not.¹⁰ Groundwater abstraction in the modernised Tadla sectors fell 43%, a result the Bank credits to reliable on-demand surface supply rather than to licence enforcement.¹¹

The lesson is unusually clean. The technology was the same in both places. What differed was a limit on how much water each farm could take, and a reliable service that made the limit tolerable.

What actually saves water

Grafton and colleagues list the conditions: robust water accounting and measurement, a cap on extraction, an assessment of uncertainty, valuation of the trade-offs, and a better grasp of how irrigators respond to incentives.⁷ Two of those can be bought. The cap needs meters, and the measurement increasingly comes from space.

Meters have lagged the hardware badly. The World Bank’s completion report for the Oum Er Rbia project records meters installed for 20 farmers in Haouz and eight in Tadla.¹¹ In Chtouka, the successor programme’s count of metered wells still stood at zero in June 2026, against a target of 4,000 by December 2027.¹²

Satellites fill part of the gap. FAO’s WaPOR service estimates crop water use from satellite data across Africa and the Near East.¹³ The Jordan Valley Authority has built it into its water information system, and Iraq’s water ministry uses a WaPOR dashboard in West Gharraf to identify illegal abstraction.¹⁴ A regulator holding that map depends less on meters that can be bypassed.

Where the market is

The hardware market is mature and competitive. The growth layer wraps it: soil-moisture sensing and scheduling, fertigation control, and above all measurement and accounting. Donor programmes now set targets for metered wells and quota systems alongside conversion.¹² Drip sells on productivity and delivers it. Whether any water is saved depends on the cap and the meter, which are usually bought separately and later.

In the region

Morocco is the regional test case, and the agriculture hub carries its detail. Saudi Arabia chose a blunter tool. It banned green fodder cultivation from November 2018, on a phase-out expected to save about 9 billion cubic metres a year, and perennial fodder in the sedimentary shelf regions stops from 16 November 2026.¹⁵¹⁶ Jordan’s farms draw about a quarter of their irrigation water from treated wastewater.¹⁷ Both take pressure off fresh water directly, rather than waiting for efficiency to do it.

The case study

One scheme in this sector, examined in full: what was built, what it cost, what worked and what did not.

Who is doing this

The buyers and operators behind the procurements this brief describes.

• Regional Agricultural Development Offices (ORMVA)Irrigation & drainage · Morocco
• Hydraulic Basin Agencies (ABH, ×10)Basin & resources authority · Morocco
• Jordan Valley Authority (JVA)Irrigation & drainage · Jordan
• Saudi Irrigation Organization (SIO)Irrigation & drainage · Saudi Arabia
• World BankDevelopment bank · Regional

Mandates, procurement routes and the rest of the region’s institutions are in the decision-maker directory.

What to watch

• 16 Nov 2026Saudi Arabia’s halt to perennial fodder in the sedimentary shelf regions takes effect, with a 50-hectare cap per licence.¹⁶
• Dec 2027Deadline for 4,000 metered wells in Chtouka and quota systems in three irrigated areas under the World Bank’s Resilient and Sustainable Water in Agriculture programme. One quota area was in place in June 2026.¹²

Further reading

• Grafton, R.Q. et al. (2018), “The paradox of irrigation efficiency”, Science. The short paper that framed the debate. doi.org
• Molle, F. (2017), Conflicting policies: agricultural intensification vs. water conservation in Morocco. The Moroccan evidence in full, free to read. horizon.documentation.ird.fr
• World Bank (2023), completion report for the Morocco Large Scale Irrigation Modernization Project. The Tadla and Haouz comparison, with its method. documents1.worldbank.org
• Cour des comptes (Morocco), Principaux axes du rapport annuel 2023–2024. The state auditor’s verdict on irrigation demand. courdescomptes.ma
• FAO WaPOR programme. Open satellite estimates of crop water consumption for Africa and the Near East. fao.org