Why desalination hasn’t solved the water crisis — and what actually would

The countries with the worst water crises have almost no desalination capacity. Not because the technology is new — large-scale desalination has existed since the 1960s. Not because nobody has tried to sell it to them — the pitch has been made repeatedly. But because the economics were structurally never going to reach them. Yemen, Ethiopia, large parts of sub-Saharan Africa and South Asia are facing acute, worsening water scarcity. They have essentially zero desalination infrastructure. The technology’s reach and the crisis’s location have almost no overlap.

This is the central problem with treating desalination as the answer to global water scarcity. The gap between the technology’s reputation — a gleaming fix to a planet-wide problem — and its actual deployment isn’t a lag that more investment will eventually close. It is a structural economic mismatch. And the solutions that would actually close that gap are not being implemented, for reasons that also have nothing to do with technology.

What Desalination Is, What It Does, and Where the Math Breaks

Desalination works by forcing seawater through semi-permeable membranes under high pressure — reverse osmosis — or by heating it until it evaporates and condensing the resulting vapour, separating fresh water from salt. Both processes are technically mature and commercially deployed at large scale. The technology is real and functional. This matters to say plainly, because the argument here is not that desalination is a fraud or a failure on its own terms.

The Gulf states run on it. Saudi Arabia, the UAE, and Kuwait derive the majority of their drinking water from desalination. Israel produces approximately 80 percent of its potable water this way, from five large seawater plants along the Mediterranean coast, and plans to reach 100 percent of domestic supply from desalination by 2050. These are operational, large-scale systems that work exactly as advertised. The question is not whether desalination works. The question is whether it can solve the global water crisis — and the answer to that is determined by economics, not engineering.

The first structural limit is energy. Reverse osmosis requires approximately 3 to 4 kilowatt-hours to produce one cubic metre of fresh water from seawater, with the most advanced plants achieving around 2.5 kWh/m³ under ideal conditions. Conventional treatment of surface water from rivers or lakes requires roughly 0.2 to 0.6 kWh/m³. Desalination costs five to fifteen times more energy per unit of water produced. The gap is large and, at the physics level, irreducible below a thermodynamic floor of approximately 1 kWh/m³.

Scale that against global consumption. Annual freshwater withdrawal runs to approximately 4,000 cubic kilometres per year. Agriculture alone accounts for around 3,000 km³ of that. To replace even a meaningful fraction of global agricultural water demand with desalinated water would require energy inputs that don’t exist at the necessary scale. This is not a future efficiency problem. It is a physics problem with direct and permanent economic consequences. The solar desalination argument — that renewable energy will eventually make this viable — is technically coherent but practically irrelevant on the relevant timeline. The capital cost of building both solar and desalination infrastructure at the required scale remains prohibitive for water-stressed low-income nations, and the aquifers currently being depleted do not have the decades required for that transition to materialise.

The second structural limit is what comes out the other end. For every litre of fresh water produced, desalination generates approximately 1.5 litres of hypersaline brine — a concentrate two to four times saltier than seawater, laden with heavy metals and residual treatment chemicals. According to a 2019 UN-backed study published in Science of the Total Environment by Jones et al., global desalination plants discharge approximately 142 million cubic metres of this brine per day, roughly 50 percent more than earlier estimates had suggested. Saudi Arabia, the UAE, Kuwait, and Qatar together account for 55 percent of global brine production.

The vast majority of this returns to the sea. Local ecological impacts near discharge points are documented: hypersaline plumes reduce dissolved oxygen, damage benthic organisms, kill seagrasses and coral, and introduce heavy metals including copper, cadmium, and lead into coastal marine environments. Research on the Persian Gulf — the highest concentration of desalination capacity on Earth — has found hypoxia, heavy metal contamination in benthic communities, and localised salinity increases near discharge points. A 2022 study in Scientific Reports by NYU Abu Dhabi researchers found that basin-wide Gulf salinity increases from desalination remain within the range of natural variability — but the same study is explicit that local discharge impacts on corals, seagrasses, and fish are a real and ongoing concern. Inland desalination faces different but equally serious brine disposal challenges: no ocean nearby means brine must be injected underground, evaporated in expensive lined ponds, or transported. None of these options is cheap or environmentally benign. Brine disposal is not a solved problem anywhere inland, and adds substantially to the real cost of desalination wherever it is attempted away from the coast.

The full economic cost of desalination, properly accounted, includes these downstream environmental costs. They appear nowhere in the price of desalinated water.

The third structural limit is capital. Large-scale reverse osmosis plants cost hundreds of millions to over a billion dollars to build, with substantial ongoing operating costs. The countries facing the most acute water crises — Yemen, Ethiopia, Pakistan, large parts of sub-Saharan Africa — cannot access the sovereign credit ratings or multilateral financing structures to build this infrastructure. The countries that can — Gulf states, Israel, Australia, Spain, coastal California — are using desalination to supplement already-functional water systems, not to reach populations that genuinely lack water.

This is the core economic verdict. The technology’s benefits flow overwhelmingly to the water-secure. Its costs — energy consumption, environmental degradation at discharge sites — are distributed more broadly. And it reaches the approximately 2 billion people globally without reliable access to safe water almost not at all. This has been true for the six decades desalination has operated at industrial scale. It is not a deployment lag that time and investment will correct. The economics structurally exclude the places and populations that need it most.

Agriculture: The 70 Percent Problem No One Wants to Name

Agriculture withdraws approximately 70 percent of all freshwater extracted globally. The UN’s World Water Development Report and the FAO’s AQUASTAT database consistently place the figure between 69 and 72 percent worldwide, rising above 90 percent in low-income countries where subsistence and commercial irrigation dominate. This single figure is the key to understanding the water crisis. Every desalination plant ever built combined produces water that is a rounding error against agricultural demand. If you want to understand why we have a water crisis, this is where you look.

The dominant irrigation method globally is still flood irrigation — water released down furrows and channels, flooding across fields. It is the least efficient method available. Water runs between crop rows, evaporates in the sun, percolates below root zones where it cannot be taken up by plants. Typical water application efficiency for flood irrigation is around 40 to 60 percent — meaning that in the worst implementations, roughly half the water extracted is wasted before it reaches a plant. Drip irrigation, which delivers water directly to the root zone through tubes and emitters, achieves efficiencies of 80 to 90 percent or better. The technology is not experimental or expensive. It is commercially available, decades old, and routinely cost-effective at any realistic water price.

The reason flood irrigation persists is that agricultural water is systematically free or near-free in most of the world. When water has no price or a nominal one, there is no economic incentive to invest in efficiency. This is not farmers being irrational. It is farmers being rational in the incentive environment they face. The incentive environment is the problem.

The subsidies are massive and largely invisible. California’s agricultural sector consumes approximately 80 percent of the state’s developed, managed water supply — about 40 percent of total statewide water use including environmental flows — while contributing around 2 percent to state GDP, according to the Public Policy Institute of California. Much of this water moves through federal infrastructure built and operated by the US Bureau of Reclamation, which has historically delivered water to agricultural users at prices representing a small fraction of full cost. The Environmental Working Group’s analysis of the Central Valley Project found that in 2002, the average price for CVP irrigation water was less than 2 percent of what Los Angeles residents paid for drinking water, and that the total subsidy received by CVP farmers was more than double what they actually paid in water charges. Agricultural interests receiving Bureau of Reclamation water have historically been exempted from paying interest on construction costs — subsidies that economists including Richard Wahl have estimated to exceed 90 percent of the actual development cost of water infrastructure in some projects.

The same dynamic operates globally, adapted to local political arrangements. Subsidised irrigation drives water-intensive crop production in regions that cannot support it without depleted aquifers or diverted rivers. Cotton across Central Asia has collapsed the Aral Sea — once the fourth-largest lake on Earth, now largely a salt flat and a health disaster — through Soviet-era irrigation schemes that continued under post-Soviet governments. Rice is cultivated in the water-scarce Punjab and Sindh regions of Pakistan, consuming water at rates the Indus system cannot sustainably provide. Almonds and pistachios — among California’s largest agricultural exports by value — are perennial crops requiring water year-round, grown in a near-desert at prices that make economic sense only because water is priced far below scarcity value.

The reform logic is not complicated: price agricultural water at or near its real scarcity value, use the revenue to fund transition assistance for smaller and subsistence farmers switching to more efficient systems, and protect genuinely poor smallholders through targeted subsidies tied to consumption volume rather than blanket below-market pricing. This design is not theoretical. Israel has implemented agricultural water markets and real pricing under sustained pressure from scarcity. Australia has moved in this direction in the Murray-Darling Basin, imperfectly and incompletely, but measurably.

The political obstacle is that agricultural constituencies hold disproportionate power in most democratic systems. Rural votes are structurally overweighted in legislatures. Farm lobbies are generously funded. The financial models of large-scale water-intensive operations are built around cheap water, and reform threatens those models directly. The persistence of flood irrigation in water-stressed regions is not an accident of geography or a technology gap. It is a political choice with identifiable beneficiaries.

Agricultural water reform also necessarily includes crop choice. The economic case for growing water-intensive crops in arid regions depends entirely on water being cheap. Price water correctly and the economics of cotton in Uzbekistan, almonds in Fresno County, and rice in Sindh no longer hold. Markets adjust what gets grown. That is not a side effect of pricing reform. It is the mechanism by which pricing reform works.

Pricing the Rest of It: The Argument That Gets Weaponised

Agricultural water is by far the largest lever, but the mispricing problem extends across all water use. Urban residential water, industrial water, and commercial consumption are systematically underpriced in most of the world, producing predictable overuse. Resources at or near zero cost get consumed in ways that would not survive price scrutiny: lawns in desert cities, car washes, industrial processes that use water wastefully, hotel pools in water-stressed regions.

The standard political objection to water pricing is that it denies a human right. This argument contains real substance. Access to a minimum quantity of water for drinking, cooking, and basic sanitation is genuinely a human right, and pricing systems that put basic water out of reach for poor households are genuinely unjust. The objection should be taken seriously.

It should also be identified clearly for what it has become in practice: a political shield deployed primarily by large water consumers to protect their subsidies. Poor households use modest quantities of water — the WHO estimates basic needs at roughly 50 litres per person per day. The people whose water bills rise substantially under correct pricing are wealthy residential users, commercial operations, and most significantly, the agricultural interests already discussed. When farm lobbies, golf course operators, and industrial users invoke the human right to water to oppose pricing reform, they are not primarily defending subsistence farmers or the urban poor. They are defending their own access to cheap water.

The policy design that addresses this honestly has been implemented and documented. South Africa’s Free Basic Water policy, introduced in 2001 as part of the post-apartheid government’s service delivery commitments, provides the first 6,000 litres per household per month at no charge — enough for basic drinking, cooking, and sanitation needs — with escalating block tariffs for consumption above that threshold, so that heavy users pay progressively more per unit. The explicit logic was that poor households, which use little water, would pay nothing, while heavy users would pay real prices. The University of Houston’s Center for Economic Growth and Opportunity has analysed the policy’s design as achieving its distributional goals. The system has problems — infrastructure delivery failures, municipal fiscal strain, political disputes over implementation — but the pricing architecture itself does what it was designed to do. It has been replicated in modified forms in Chile and parts of Europe.

The broader point is this: when lifeline pricing is opposed in any jurisdiction, the opposition comes from industry, agriculture, and upper-income residential consumers — not primarily from the poor households the objection claims to protect. South Africa’s free water policy faced its most sustained political resistance not from township residents who depended on it but from municipalities under pressure from commercial water users, and from national debates about cost recovery driven by industrial and commercial interests. In California, the agricultural lobby that has spent decades blocking water pricing reform invokes small family farmers in its public messaging while representing operations consuming hundreds of thousands of acre-feet annually at subsidised rates. The gap between the stated concern and the actual constituency is, in every case, the same.

Groundwater: The Crisis Nobody Can See Until It’s Gone

Groundwater depletion is the water emergency that happens invisibly, then suddenly. Major aquifers globally are being drawn down at rates with no precedent and no equilibrium. The Ogallala Aquifer underlies approximately 174,000 square miles of the American Great Plains across eight states and supplies roughly 30 percent of all US groundwater used for irrigation. In parts of Texas, recharge from precipitation reaches the aquifer at less than a millimetre per year. Water table declines of 1 to 3 feet per year are common in western Kansas and the Texas Panhandle, where the Texas A&M Ogallala Aquifer Program documents them. In some areas the water table has dropped more than 100 feet since large-scale pumping began after World War II. Scientific American has reported that the aquifer is currently being depleted at an annual volume equivalent to 18 Colorado Rivers.

The North China Plain aquifer — which irrigates wheat and maize production feeding hundreds of millions of people — is in comparable trouble. So are major aquifer systems under Punjab in India and Pakistan, where rice and wheat cultivation at enormous scale has depended on groundwater extraction for decades. These are not isolated regional problems. They are simultaneous, large-scale depletions of water stocks accumulated over millennia, being liquidated on timescales measured in decades.

The economics of unmanaged groundwater is a textbook tragedy of the commons. Every individual farmer has a rational incentive to pump as much as possible before neighbours do. Any water left in the aquifer is available to everyone. The individually rational strategy — extract now — produces the collectively catastrophic outcome: depletion. For fossil aquifers with geological recharge timescales, depletion is effectively permanent. Hundreds to thousands of years of rainfall would be needed to replace what has been extracted from parts of the Ogallala. Once these systems are gone, they are gone on any timescale relevant to human planning.

The connection to desalination deserves explicit treatment because it illustrates exactly how misaligned the dominant policy response is. In parts of the American West and the Middle East, desalination plants are being built or seriously proposed in regions simultaneously depleting their aquifers through agricultural extraction. The structural logic is: desalination provides urban drinking water while agriculture continues to drain the shared aquifer below. The most capital-intensive, energy-intensive water solution available is deployed to treat the symptom — urban water shortfall — while the underlying cause — unpriced agricultural groundwater extraction — continues unchallenged. The expensive solution and the liquidation of the common resource proceed in parallel.

The answer to groundwater depletion is governance: extraction limits based on sustainable yield, monitoring infrastructure, enforceable water rights reform, and institutions with real authority to reduce allocations when aquifer levels decline. None of this requires new technology. All of it requires overriding the interests of current extractors, who hold significant economic and political power in the regions where this matters most.

Australia’s Murray-Darling Basin provides the most instructive example of what serious governance reform actually looks like. By the 1990s, the river system was so severely over-allocated — irrigation licences had been issued for more water than the system could sustainably provide — that the lower Murray was regularly failing to reach the sea, and the basin’s ecosystems were in documented decline. The Murray-Darling Basin Plan was legislated in November 2012, imposing mandatory caps on extraction and creating a water market in which rights could be traded, with the federal government committing approximately A$13 billion to buy back irrigation entitlements from willing sellers. The original target was 3,000 to 4,000 gigalitres of water returned to environmental flows. The final legislated figure was 2,750 GL — substantially less, after years of agricultural industry pressure. In 2015, the government capped water buybacks at 1,500 GL under lobbying from irrigators and farm groups including the National Farmers’ Federation. The plan has been bitterly contested, repeatedly litigated, partially amended downward, and only incompletely implemented.

It is also the most serious attempt by any government to treat a major shared water system as a managed commons rather than a free extraction resource, and ecological conditions in the river have measurably improved in reaches where environmental water has been returned. It is not a success story. It is a demonstration of what serious governance actually requires: years of conflict with powerful agricultural constituencies, political retreats, incomplete implementation, and ongoing litigation. It is also, demonstrably, better than the alternative of doing nothing.

Why the Wrong Answer Keeps Getting Built

Desalination gets funded — by governments, development banks, infrastructure investors — because it is politically costless. It creates new water supply without taking anything from anyone. No agricultural pricing reform. No groundwater extraction limits. No confrontation with any powerful water-using constituency. Politicians can announce a water solution and cut a ribbon on a new plant without incurring the costs that a real solution requires. This is desalination’s primary political virtue, and it has nothing to do with water.

The pattern extends into international development finance. Multilateral development banks and bilateral aid programmes have directed significant capital into desalination projects in water-stressed developing nations while the same regions’ agricultural water pricing goes unreformed and groundwater governance remains absent. The structural reason is mundane: a desalination plant is a capital project with a defined cost, a measurable output (cubic metres of water per day), and a loan structure that development finance institutions understand. It generates engineering contracts, often for firms in donor countries. Governance reform — repricing agricultural water, establishing groundwater extraction limits, building and enforcing a water rights regime — is none of those things. It cannot be structured as a fixed-capital loan. It does not produce a ribbon-cutting ceremony. It requires sustained institutional engagement over decades and generates opposition from constituencies with political access. It is, in the vocabulary of development finance, not fundable in the same way.

This is how well-intentioned money makes problems worse: by directing resources toward the legible, concrete intervention and deferring the necessary, contested one.

The water crisis is a governance failure that has been persistent enough, and politically convenient enough to misdiagnose, that it now presents itself as a technology gap. The solutions are known, economically coherent, and proven in the jurisdictions that have implemented them under sufficient pressure. Israel built serious water governance alongside its desalination capacity — real agricultural pricing, wastewater recycling at scale (Israel reuses over 80 percent of treated wastewater for agriculture, the highest rate in the world), and managed demand. Australia’s Murray-Darling reform, for all its limitations, is more ambitious than anything attempted in most of the world’s over-allocated river systems. Singapore, with no meaningful natural freshwater catchment, built a four-tap supply strategy that includes heavily treated reclaimed wastewater — branded NEWater — now supplying roughly 40 percent of national demand, alongside tiered pricing that makes consumption above basic needs progressively expensive.

The pattern across all of these cases is the same: serious water governance reform happened when the politically easier options had visibly failed and the political cost of reform fell below the cost of continuing without it. Desalination, emergency aquifer drilling, and demand-side stopgaps typically come first. Governance reform comes when those options have been exhausted.

Most of the world is still exhausting the easier options. Whether serious governance reform arrives before the aquifers run out is not a technology question. It is a question about political economy, about which interests lose power when water is priced correctly, and about whether the people who bear the cost of that answer — primarily future water users — can organise politically against the people who benefit from the current arrangement. The track record is not encouraging. The alternative is not an abstraction: it is aquifer systems that do not recharge on human timescales, irrigated food production that collapses when the water is gone, and water crises that become permanent rather than manageable. That is where the current arrangement leads, and no desalination plant changes it.

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Reverse osmosis desalination plant – Wikipedia (James Grellier)

Key Sources and References

Desalination energy consumption (RO, 3–4 kWh/m³ typical; 2.5 kWh/m³ advanced): Ghaffour, N., Missimer, T.M., and Amy, G.L. (2013). Technical review and evaluation of the economics of water desalination: Current and future challenges for better water supply sustainability. Desalination, 309, 197–207. See also: Hannah Ritchie, “How much energy does desalinisation use?” Sustainability by Numbers, September 2024. https://hannahritchie.substack.com/p/how-much-energy-does-desalinisation

Conventional surface water treatment energy consumption (0.2–0.6 kWh/m³): Plappally, A.K. and Lienhard V, J.H. (2012). Energy requirements for water production, treatment, end use, reclamation, and disposal. Renewable and Sustainable Energy Reviews, 16(7), 4818–4848.

Global desalination brine discharge: 142 million m³/day: Jones, E., Qadir, M., van Vliet, M.T.H., Smakhtin, V., and Kang, S. (2019). The state of desalination and brine production: A global outlook. Science of the Total Environment, 657, 1343–1356. https://doi.org/10.1016/j.scitotenv.2018.12.076

1.5 litres of brine per litre of freshwater produced: Jones et al. (2019), ibid. Also confirmed by UN University press release, January 14, 2019. https://phys.org/news/2019-01-toxic-brine-desalination.html

55% of global brine from Saudi Arabia, UAE, Kuwait, Qatar: Jones et al. (2019), ibid.

Persian Gulf — local ecological impacts of brine discharge (heavy metals, hypoxia, benthic damage): Sharifinia, M. et al. (2025). Impact of desalination plant brine discharge on macrobenthic communities in the Persian Gulf. Journal of Sea Research. https://www.sciencedirect.com/science/article/abs/pii/S0967064525000141

Persian Gulf — basin-wide salinity increases within natural variability range (nuance): Paparella, F. et al. (2022). Long-term, basin-scale salinity impacts from desalination in the Arabian/Persian Gulf. Scientific Reports, 12, 20678. https://doi.org/10.1038/s41598-022-25167-5

Agriculture: ~70% of global freshwater withdrawals: UN World Water Development Report 2024, UNESCO. https://www.unesco.org/reports/wwdr/en/2024/s. FAO AQUASTAT: https://www.fao.org/aquastat/en/overview/methodology/water-use/

Israel: ~80% of potable water from desalination: Israeli Water Authority officials, cited in GovTech, April 2021. https://www.govtech.com/fs/desalination-in-israel-means-robust-water-resilience-.html. Also: University of Texas Water Resources Podcast, https://wrp.beg.utexas.edu/node/31

Flood irrigation water application efficiency (~40–60% efficient; ~50% waste): Water Footprint Calculator. “Why All Farms Don’t Use Drip Irrigation.” https://watercalculator.org/footprint/farmers-use-drip-irrigation/. Also: Brower, C. et al. (1989), referenced in ScienceDirect, Irrigation Efficiency overview: efficiencies for surface systems ~60%, drip ~90%.

Drip irrigation efficiency: 80–90%+: ScienceDirect Topics, Irrigation Efficiency, citing Brower et al. (1989). https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/irrigation-efficiency

California agriculture: ~80% of developed/managed water supply: California Department of Water Resources: “agriculture accounts for approximately 80 percent of all developed water.” https://water.ca.gov/Programs/Water-Use-And-Efficiency/Agricultural-Water-Use-Efficiency. Also: Public Policy Institute of California: “farms use approximately 40% of the state’s water, or 80% of all water used by homes and businesses.” https://www.ppic.org/publication/water-use-in-californias-agriculture/

California agriculture: ~2% of state GDP: Public Policy Institute of California, Water Use in California’s Agriculture, July 2024. https://www.ppic.org/publication/water-use-in-californias-agriculture/. Also cited in ABC News, 2015: “Agriculture, which consumes 80 percent of the state’s water and accounts for only 2 percent of the state economy, according to the Public Policy Institute of California.” https://abcnews.go.com/US/california-water-rules-leave-agriculture/story?id=30843208

Bureau of Reclamation / CVP water prices: less than 2% of LA drinking water price; subsidies exceeding 90% of development cost in some projects: Environmental Working Group, California Water Subsidies, 2004. https://www.ewg.org/research/california-water-subsidies. EBSCO Research Starters, U.S. Bureau of Reclamation: “overall subsidy to farmers is believed to be considerable, in some cases exceeding 90 percent of the actual cost of water development.” https://www.ebsco.com/research-starters/science/us-bureau-reclamation-usbr

Aral Sea collapse from Soviet cotton irrigation: Broadly documented. For overview: Micklin, P. (2007). The Aral Sea Disaster. Annual Review of Earth and Planetary Sciences, 35, 47–72.

Ogallala Aquifer: recharge under 1mm/year in parts of Texas; water table declines of 1–3 feet/year; depletion equivalent to 18 Colorado Rivers: Wikipedia, Ogallala Aquifer (citing USGS data): recharge 0.024 inches/year in parts of Texas. https://en.wikipedia.org/wiki/Ogallala_Aquifer. Texas A&M Ogallala Aquifer Program: “depletion rates of 1 to 3 feet per year are common” in western Kansas and Texas High Plains. https://ogallala.tamu.edu/?p=301. Scientific American: “the Ogallala Aquifer is being depleted at an annual volume equivalent to 18 Colorado Rivers.” https://www.scientificamerican.com/article/the-ogallala-aquifer/

South Africa Free Basic Water Policy: 6,000 litres/household/month free; implemented 2001: University of Houston, Center for Economic Growth and Opportunity: “The Free Basic Water Policy was introduced in 2001 and provides 6 kiloliters of water per month at no cost to households.” https://www.uh.edu/class/economics/cego/research/economic-development/water-project/study-one/. Also: Water Alternatives blog, November 2023. https://www.water-alternatives.org/index.php/blog/fbw

Murray-Darling Basin Plan: legislated November 2012; 2,750 GL target; A$13 billion committed; buyback cap of 1,500 GL in 2015; contested and partially implemented: The Conversation, “Water buybacks are back on the table in the Murray-Darling Basin,” Global Water Forum, February 2023. https://globalwaterforum.org/2023/02/27/water-buybacks-are-back-on-the-table-in-the-murray-darling-basin-heres-a-refresher-on-how-they-work/. Australian Department of Agriculture, Forestry and Fisheries: https://www.agriculture.gov.au/abares/research-topics/water/the-impacts-of-further-water-recovery. The Conversation, “Australia’s watergate”: https://theconversation.com/australias-watergate-heres-what-taxpayers-need-to-know-about-water-buybacks-115838

Israel: >80% of treated wastewater recycled for agriculture: Israeli Water Authority / GovTech, April 2021: “The country treats and recycles more than 80 percent of its wastewater, using it primarily for agriculture, making it a world leader in that.” https://www.govtech.com/fs/desalination-in-israel-means-robust-water-resilience-.html

Singapore NEWater: ~40% of national demand; tiered pricing: PUB, Singapore’s National Water Agency. “NEWater.” https://www.pub.gov.sg/watersupply/fournationaltaps/newater. Singapore’s four national taps strategy and progressive tariff structure are documented on the PUB website and in: Tortajada, C. (2006). Water Management in Singapore. International Journal of Water Resources Development, 22(2), 227–240.