
Water in Iran
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Overview
Iran is a high plateau ringed by mountains, and about 90% of the country is arid or semi-arid.1 2 Dams, wells and long transfers underpin an agricultural economy that uses more than 90% of the water supply.3 The costs are visible in sinking plains, a shrunken Lake UrmiaLake Urmia A salt lake in north-western Iran, the largest lake in the Middle East. Like the Dead Sea, it is known for the extreme salinity of its water. Source: Lake Urmia, Encyclopædia Britannica and reservoirs drained by drought.4 5 3 Desalinated water from the Gulf now reaches the central plateau.6
Iran’s water has long come from underground. Across its arid regions, qanats carried groundwater by gravity from the heads of valleys to farms and towns, and until the 1920s Tehran drew its water only from qanats.7 8 In 2016, UNESCO inscribed eleven of them as The Persian Qanat.7 Motor-pump wells arrived in the early 1950s,9 and between 1954 and 1977 total outflow from the qanats fell from 574 to 224 m³ a second.8 By around 2000, annual discharge from wells, qanats and springs had risen to more than 74 billion m³, from less than 20 billion in the early 1970s.1
Pumping has outrun recharge. FAO put groundwater depletion at 3.8 billion m³ a year, mostly in the central basins,1 and parts of the central plateau are sinking by more than 35 cm a year.4 Drought has deepened the strain. By the count of World Weather AttributionWorld Weather Attribution An international collaboration of climate scientists, founded in 2014, that measures how far climate change has made a particular heatwave, drought, storm or extreme rainfall more likely or more intense, often within days or weeks of the event. Source: About, World Weather Attribution, the year to June 2025 was Iran’s fifth consecutive dry year, in a drought it measured from July 2020,10 and the autumn that followed was the driest in 50 years.11 By November 2025, nineteen major dams were effectively empty.11 3 That month, President Pezeshkian warned that Tehran, a city of 10 million, might face rationing and even evacuation if the rains failed again.3
Snapshot
Baseline water stress14
Against the scarcity line
Total renewable water per person, including inflows from upstream (2023): below the 1,700 m³ water-stress line. Falkenmark thresholds: water stress below 1,700, water scarcity below 1,000, absolute water scarcity below 500 m³ per person per year.15
Key institutions
- Ministry of Energy (water affairs)Ministry
- Ministry of Agriculture-JahadMinistry
- Iran Water Resources Management CompanyResources holding company (Ministry of Energy)
- Provincial water & wastewater companies (Abfa)Utility
Financing & PPP
- PPP frameworkEmerging
- Tracked projectsUS$ 26.0 bn disclosed value in our projects register, of which US$ 22.1 bn pipeline (not yet operating)
- Active fundersDomestic finance, National Development Fund
- Climate adaptation planIn preparation (GCF support approved 2025)
Key challenges
- 01Severe groundwater depletion & land subsidence
- 02Drying wetlands (Lake Urmia)
- 03Very high agricultural water use
- 04Inter-basin transfer controversies
Developments to watch
- 0188 dams under construction, to regulate about 7.5 billion m³ a year
- 02Volumetric smart meters on farm wells: about 125,000 of 416,000 by August 2026
- 03Draft guideline (August 2026) to transfer part of agricultural water management gradually to farmers and their organisations
- 04National Climate Change Management Plan, adopted October 2025
Sources and notes
Population: World Bank WDI, 2025.
Total water withdrawal and its split by sector: FAO AQUASTAT, estimate for 2023. The 2023 figures repeat the split last reported for 2004; FAO flags every year after 2004 as imputed (carried forward), so they are an estimate carried forward from 2004, not a new measurement.
Total renewable water per person: FAO AQUASTAT, 2023.
Land subsidence: Science Advances, 2024.
Drinking water: WHO/UNICEF Joint Monitoring Programme (JMP), 2024 estimates, via the World Bank WDI.
Baseline water stress: WRI Aqueduct 4.0 country rankings (2023), baseline water stress, all sectors, 1979–2019: total water demand as a share of available renewable surface and groundwater supply, scored 0–5 and averaged over the country weighted by water demand.
Against the scarcity line: FAO AQUASTAT, 2023.
Sources: Water use by sector and total water withdrawal: FAO AQUASTAT, estimate for 2023; freshwater withdrawal by source: FAO AQUASTAT, 2020; FAO AQUASTAT Dissemination System, retrieved 20 October 2026. No desalination or reuse share is shown: AQUASTAT's latest desalination figure (2022) has no official total withdrawal for the same year. Population and GDP: World Bank WDI, latest year (shown on each tile). Other figures: FAO AQUASTAT / national reports, latest available, approximate.
Water map
One interactive map of Iran's water, built from real geodata. Climate & drought maps the aridity gradient (WorldClim) with warming projections. The Water risk layer's WRI Aqueduct indicators, covering overall water risk, water stress and flood risk (plus groundwater decline where the trend is significant), shade every river sub-basin by its 0–5 risk score. Demand shows where the population, and the water demand, concentrate. Infrastructure brings the physical system together: rivers, dams (FAO AQUASTAT), treatment plants, desalination and the major conveyors. Shared waters outlines the transboundary river basins and aquifers that Iran shares with other countries, each drawn in full across the border; hover an outline for the countries that share it. Hover any sub-basin or marker for detail; sources are cited under each view.
Sources and notes
Interactive map: switch views, hover or focus a marker, and use the +/− controls (or double-click, then drag) to zoom and pan. Geometry and data from the MENA Water Review library.
Geography & climate
Iran is a high plateau ringed by mountains. About 52% of the country is mountain or desert, and some 16% lies above 2,000 m.1 The Zagros, the largest massif, runs from the north-west down to the Gulf coast and on to the far south-east.1 The Alborz follows the Caspian shore. Its peak, Damavand, reaches 5,600 m, while the Caspian Sea lies about 28 m below sea level.2 Between the chains, the Central Plateau covers more than half the country, partly salt flats and partly sand or stone.1
The national communication divides the land into six main basins. The Central Plateau basin alone covers about 824,000 km², roughly half the basin area. The Persian Gulf and Oman Sea basin covers about 423,000 km².2 The Caspian, Eastern border, Lake Urmia and Ghareh-Ghom basins make up the rest.2
Rainfall
Rain is scarce and unevenly spread. Annual rainfall ranges from under 50 mm in the deserts to 2,275 mm at Rasht near the Caspian.1 National estimates of the average range from 228 mm to about 240 mm, and about 90% of the country is arid or semi-arid.1 2 Half of the rain falls in winter, 23% each in spring and autumn, and only 4% in summer.1 About 30% of precipitation comes as snow.2 Of 417 billion m³ of precipitation a year, 299 billion m³, or 72%, evaporates.2
Single years swing hard. From October 2024 to 7 March 2025, official data showed 93.8 mm of rain against a long-term average of 157.8 mm for the period.16 Hormozgan was 77% below normal and Sistan-Baluchestan 72% below.16 By early November 2025 the country had received only 2.3 mm, 81% below the historical average.3
In the World Bank Climate Change Knowledge Portal’s ERA5 reanalysis, averaged over the whole of Iran, about 289 mm of rain falls in a year (1991–2020). Station records and national averages use other sources and baselines, so their figures can differ (the text cites national estimates of 228 mm to about 240 mm). About 46% of the rain falls in January, February and March. Average rainfall in 1993–2022 was about 4% lower than in 1951–1980, and single years swing widely around that.
The year in rain and heat
Monthly rainfall (bars, mm) and mean temperature (line, °C), country average 1991–2020
Heat and drought
The climate is strongly continental. Away from the coasts, the annual temperature range is about 22–26 °C.2 Summer temperatures in the interior have passed 55 °C, and winter lows reach −30 °C in the north-west.1 Heat now strains power and water together. In July 2025, with temperatures above 50 °C in some regions, Tehran declared a public holiday to save electricity and water.17
Drought has become the norm. Human-induced warming made the 2020–2023 drought in Iran 16 times more likely, an attribution study found. Heat, not falling rain, drove the change.18 By 2025 the country was in its fifth consecutive drought year, the worst on record.10 A year-long drought like that of July 2024 to June 2025 is now expected about once a decade. In a world 1.3 °C cooler it would come once every 50 to 100 years.10
The same reanalysis gives a mean temperature of 18.3 °C for 1991–2020 and a warming of about 0.54 °C a decade over 1971–2022. Station records and national reports use other sources and periods, so their warming rates can differ.
Annual rainfall, 1950 to 2022
Country average, mm
Annual mean temperature, 1950 to 2022
Country average, °C
Projections and the coast
Models agree on heat far more than on rain. The World Bank’s CMIP6 ensemble shows small rainfall changes of either sign, as the table below sets out. Under high emissions, Iran would have about 68 more days a year above 35 °C by 2080–2099, nearly double the 74 days of 1995–2014.19 Its hottest day of the year would be about 6.7 °C hotter.19 The national communication estimates that a 2 °C rise cuts groundwater recharge by 20% and snowfall by 5%. Snowmelt comes a month earlier and the snow line rises by 200 m.2 Under its pessimistic scenarios, runoff falls in every basin, by up to 65.5% in the Bandar Abbas–Sedij basin.2
The Gulf coast faces the sea as well as the heat. Tide gauges show sea level at Bandar Abbas rising by 2.34 mm a year.2 The worst scenario for 2100 would flood low-lying coast in Khuzestan and parts of Hormozgan, and could affect groundwater.2 Under high emissions and without major adaptation, about 184,700 people a year could be affected by coastal flooding in 2070–2100.2
Projected change for Iran
The table gives the CMIP6 multi-model median from the same World Bank portal, as change against 1995–2014. Projections cited in the text may use other models, scenarios or baselines, so their figures can differ.
| Scenario | Temperature, 2040–2059 | Rainfall, 2040–2059 | Temperature, 2080–2099 | Rainfall, 2080–2099 |
|---|---|---|---|---|
| Middle of the road (SSP2-4.5) | +1.8 °C | +4% | +2.9 °C | +4% |
| High emissions (SSP5-8.5) | +2.4 °C | +3% | +5.6 °C | −1% |
Sources and notes
Source: World Bank Climate Change Knowledge Portal, retrieved September 2026. ERA5 0.25° reanalysis for the annual series (1950–2022) and the monthly climatology (1991–2020); CMIP6 0.25° multi-model ensemble median for the projections, as change against 1995–2014. These are national averages, which hide the gap between wet highlands and dry interiors, and reanalysis rainfall over deserts carries wide uncertainty.
Water resources: the groundwater reckoning
Groundwater is the story. Discharge from wells, qanats and springs rose from less than 20 billion m³ a year in the early 1970s to more than 74 billion m³ around 2000.1 Over the same period the number of wells grew fivefold, from just over 9,000 to almost 45,000.1 FAO put groundwater depletion at 3.8 billion m³ a year, mostly in the central basins where surface water is scarce.1 Qanats, the tunnels that tap aquifers by gravity, still run from about 100 m to 120 km in one Yazd system.1
The large rivers lie on the edges of the plateau. One report cited by the Washington Institute says 45% of the Karun’s flow has been diverted from its natural course.20 Dams regulated 34 billion m³ of surface water in 2006, of which 20.51 billion m³ was used.2
Sinking plains
The deficit shows in the ground. A national satellite survey for 2014–2020 found about 56,000 km², 3.5% of Iran, subsiding, mainly because of irrigation. About 3,000 km² sinks faster than 10 cm a year, and parts of the central plateau faster than 35 cm.4 The western Tehran plain subsided at more than 25 cm a year between 2003 and 2017.21 Around Isfahan the rate ran from 5 to 100 mm a year in 2014–2019.22 At Rafsanjan, groundwater overdraft rose about sixfold between 1969 and 1999, and the water table fell about 28 m.23
Supply by source
In FAO AQUASTAT, Iran’s freshwater withdrawals in 2020 were 47.7 billion m³ from surface water and 44.3 billion m³ from groundwater. There is no matching figure for desalination or reuse for that year, so no full supply mix is charted.13
The main rivers
The table ranks the rivers of Iran by the largest natural flow they reach inside the country. Natural flow is the modelled long-term average before any withdrawals. For a heavily used river it measures what the river could carry, not what arrives today.
| River | Also flows through | Length in Iran, km | Natural flow, m³/s | Free-flowing |
|---|---|---|---|---|
| Shatt al-Arab (Arvand Rud) | Iraq | 88 | 2,960 | 0% |
| Karun | – | 796 | 748 | 5% |
| Helmand | Afghanistan | 82 | 510 | 0% |
| Qezel Owzan | – | 645 | 320 | 11% |
| Karkheh | Iraq | 792 | 296 | 10% |
| Aras | Armenia, Azerbaijan, Turkey | 420 | 179 | 0% |
| Hari Rud | Afghanistan, Turkmenistan | 264 | 175 | 100% |
| Zarineh Rud | – | 222 | 164 | 0% |
| Sirwan (Gaveh Rud) | Iraq | 128 | 154 | 0% |
| Mand | – | 415 | 120 | 100% |
The dams on these rivers, from the FAO AQUASTAT inventory, are listed river by river under Infrastructure.
Sources and notes
Sources: Grill, Lehner, Thieme et al. (2019), Mapping the world’s free-flowing rivers, Nature 569, dataset under CC BY 4.0, for length, natural flow (WaterGAP, 1971–2000) and free-flowing status, meaning the share of the river’s length inside Iran still classed as free-flowing. No flow figure is given below 20 m³/s, where a global model is too coarse to rank small rivers. The same rivers are drawn on the water map above under Rivers & lakes. For Iran: the Hari Rud’s 100% free-flowing share is the dataset’s value, while the AQUASTAT inventory lists the 1,250 MCM Doosti (Dousti) Dam on the river (see the dams by river under Infrastructure), so the two do not agree.
Water use
Iran withdrew about 93.3 km³ of water in 2004, FAO estimated: 53.1 km³ from groundwater, 40 km³ from surface water and 0.2 km³ from desalination. Agriculture took about 92%, the same share as in 1993.1 Withdrawals that year equalled almost 68% of renewable resources.1 In the year to March 2025 more than 90% of supply still went to agriculture, which produced about 12% of GDP. Households are believed to use less than 8%.3
The pumping boom
The area equipped for irrigation grew from 7.26 million ha in 1993 to 8.13 million ha in 2003, about 62% of it fed from groundwater.1 Efficiency stayed low. Surface methods covered 91.4% of the irrigated area in 2003, and national irrigation efficiency averaged about 33%.1 In 1995 farmers paid US$0.2–0.8 per 1,000 m³ of delivered water, while pumping groundwater cost US$5–9.1
Transfers
Transfers move the conflict between provinces. Farmers in Isfahan have protested transfers of Zayandeh Rud water to Yazd since at least 2012, and the river has had no permanent flow since 2006.24 25
Lake Urmia
Lake Urmia peaked in 1995. Over the next two decades its level fell more than 7 m and it lost about 90% of its area.5 By 2013 its volume had fallen sixtyfold, to 500 million m³.26 A restoration programme launched that year had cost about US$1 billion by 2021. It worked to move farmers off sugar beet and began diverting up to 600 million m³ a year from the Little Zab.26 A 2025 study attributes about 66% of the fall in river inflows to agricultural water use, as irrigated land grew more than fourfold between 1985 and 2020.27 The lake fell below 1,270 m in September 202328 and to 1,269.50 m by September 2025. Officials reported 1,270.70 m in April 2026, still 3.4 m below its ecological level.29
Use by sector
Agriculture is the largest user of water in Iran, at roughly 92% of total water withdrawal; the full split is agriculture (92%), municipal (7%), industry (1%), in FAO AQUASTAT’s figures for total water withdrawal (FAO estimate for 2023)13.
Withdrawals by sector
Million m³ a year, FAO estimate for 2023
- Agriculture86,000 MCM · 92%
- Municipal6,200 MCM · 7%
- Industry1,100 MCM · 1%
Withdrawals over time
FAO’s AQUASTAT estimates put Iran’s freshwater withdrawals at 45.0 billion m³ in 1975, 93.0 billion m³ in 2004 and 92.0 billion m³ in its latest official figure (2020).13 Agriculture’s share of the total stayed at about 92% between 1994 and the latest estimate (2004).
Freshwater withdrawals, 1975 to 2022
Total, billion m³ a year
Sources and notes
Source: FAO AQUASTAT via the World Bank World Development Indicators, retrieved September 2026. AQUASTAT revises national figures irregularly and fills the years between surveys, so a jump between two adjacent years usually marks a new national estimate rather than a change on the ground. The World Bank series charted here carries AQUASTAT’s 2004 estimate of Iran’s freshwater withdrawals forward unchanged to 2022. Total water withdrawal and its split by sector: FAO AQUASTAT, estimate for 2023. The 2023 figures repeat the split last reported for 2004; FAO flags every year after 2004 as imputed (carried forward), so they are an estimate carried forward from 2004, not a new measurement. Water stress (SDG 6.4.2): FAO, the custodian agency for the indicator. FAO. 2026. AQUASTAT Core Database. Food and Agriculture Organization of the United Nations. Database accessed on 2026/10/20.30 FAO gives 80% for 2023, flagged E: an estimate calculated or identified from official values or from an AQUASTAT estimation, in FAO’s definition. This figure is carried forward, not a new measurement: it repeats the value FAO gives for 2020. Iran’s total freshwater withdrawal, from which the indicator is calculated, has not changed in AQUASTAT since 2020; FAO flags it imputed (carried forward) from 2021. The withdrawal behind FAO’s value is 91,966 million m³ for 2023 (flag I); the World Bank series charted here shows 92,950 million m³ for 2022.
Water for farming
Estimates of how much of Iran’s water goes to farming now diverge widely, as the table shows. On the ministry’s own account the pattern for 2025–26 was issued with a 10% cut in water use, about 5 billion m³.31 Agriculture’s share of groundwater consumption fell from 91.0% in 2002 to 87.6% in 2015, while the number of extraction points rose 84.9%, from 546,000 to over a million; the share of groundwater supplied by qanats fell from 10.8% to 7.6%.32 The deputy minister for crops said in November 2025 that 500,000 unlicensed wells remained unresolved and that the volumetric meters the law requires were not yet in place;33 in May 2026 a water-industry spokesman reported about 28,000 illegal wells blocked since the previous year.34 Smart meters on authorised wells are under Water use.
| Date | Source | Estimate |
|---|---|---|
| 2021 | Noori and others, PNAS | More than 90% of water withdrawal |
| July 2025 | AFP | As much as 80% of water consumption |
| August 2025 | Deputy agriculture minister | About 70 billion m³ a year on the energy ministry’s statistics, including unlicensed wells |
| November 2025 | Deputy agriculture minister for crops | Not more than 50% of national water use |
Sources and notes
Table sources: Noori and others (PNAS, 14 June 2021), AFP via Circle of Blue (31 July 2025), Taadol (18 August 2025, Gholamreza Golmohammadi) and Donya-e-Eqtesad (9 November 2025, Majid Anjafi).32 35 31 33 The estimates rest on different bases (withdrawal or consumption, with or without unlicensed wells) and the sources do not reconcile them. An older estimate, from the FAO AQUASTAT country profile (2008 edition), is 86 km³ withdrawn for agriculture in 2004, 92% of withdrawals.1 FAO’s equipped area of 8.7 million ha was last reported for 2009 (an FAO estimate) and its split by method for 2003, when 7.43 million ha were under surface irrigation, 280,000 ha under sprinklers and 420,000 ha under localised irrigation; the database repeats later values (flag I).36 The Noori study counts about 5.9 million ha irrigated, a different concept from equipped area. “Modern irrigation” is not defined in the ministry statements and may include improvements that are not pressurised; a 2018 paper put pressurised systems at 1.4 million ha (16.1% of suitable land). Well counts differ: about 320,000 illegal wells (2019), about 330,000 of 800,000 wells unpermitted (a study using data to 2015–2016) and 500,000 unlicensed (2025), with counting methods unstated. The Noori figures on groundwater use are for 2002 to 2015, the last years its authors had data for. AQUASTAT holds no values for the area or volume of treated wastewater used in irrigation in Iran. The Third National Communication could not be re-read for this section, and no count of working qanats and no official text of the 2025–26 crop pattern notice was found.
Irrigation methods
The surface-irrigation share in FAO’s last count (2003) is under Water use. In April 2025 the Ministry of Agriculture said about 3.1 million ha were equipped with modern irrigation and 2.5 million ha of irrigable land still needed upgrading, with a target of 70,000 ha for the year to March 2026, depending on funds.37 In November 2025 the deputy minister said more than 90% of pulses were grown under modern irrigation, but that rollout was slow and that under 5,000 billion toman had been allocated against about 175,000 billion needed for water and soil projects.33
Crop pattern
The Ministry of Agriculture unveiled a national crop-pattern plan in the Iranian year 1401 (from March 2022), with 17 provinces prioritised.38 For 2025–26 only specified provinces were licensed to grow rice, and a farmer who plants rice, watermelon or other water-intensive crops outside the pattern loses ministry subsidies.31 Provinces have added bans of their own: rice in the Karkheh, Dez, Karun, Marun, Jarrahi and Zohreh basins of Khuzestan from May 2025,39 and in the plains of eastern Kermanshah in January 2026.40
Treated wastewater
FAO’s profile said treated wastewater was “said to be indirectly used in agriculture”.1 A 2023 review states that about 55% of treated municipal effluent is reused, with an emphasis on agriculture.41 The deputy minister said in 2025, however, that farming with sewage is banned by law and that only effluent of standard quality from tested plants may reach farms.33 The register lists the Tabriz wastewater treatment plant, whose effluent is intended for irrigation; the irrigation dams of Karkheh, Dez, Karun and others are on the Agriculture & Food hub.
Infrastructure
Dams carry the system. In 2006, 94 large storage dams with a capacity of 31.6 billion m³ were operating. Another 85, holding 10 billion m³, were under construction.1 Iran became the world’s third-largest dam builder after China and Japan.24 Building goes on. In August 2025 the head of the Planning and Budget Organization said 88 dams under construction would regulate about 7.5 billion m³ a year.42 Silt is a hidden cost. Sedimentation averages 10 tonnes per hectare a year in Iran, against under two tonnes worldwide.2
Tracked projects
| Asset class | Projects | Disclosed value | Largest by value |
|---|---|---|---|
| Desalination | 8 | US$ 25,980 m | Persian Gulf Desalination & Conveyance, line 2 |
| Wastewater and reuse | 5 | – | – |
| Conveyance, storage and dams | 21 | – | – |
| Networks and other | 6 | – | – |
Open the project database for Iran
Reservoirs under drought
The dams are only as full as the rain allows. On 9 November 2025, official figures showed reservoirs holding 17.12 billion m³, 33% of capacity. A year earlier they held 22.92 billion m³.43 Inflows since late September were 1.48 billion m³, half the previous year’s 3 billion.43 Nineteen dams were below 5% of capacity, and Tehran’s five supply dams averaged about 10%.3 Tehran’s Lar reservoir held 2% of capacity and Latyan about 9%.44 About 70% of the capital’s water comes from those five dams.17 Winter brought only partial relief. On 20 February 2026 the major dams were 41% full, but Tehran’s five held just 132 million m³ between them.45
Moving water to the plateau
Transfers now move water over long distances. On 6 December 2025 the president inaugurated a project that carries desalinated water from the Persian Gulf and the Sea of Oman to the central plateau, on a route from Sirjan to Isfahan.6 46 The 800 km pipeline took two years and cost 350 trillion rials, about US$320 million.46 6 Built with major support from Mobarakeh Steel, it supplies industry in Isfahan Province.46 In July 2025 a 339 km branch entered pilot operation, aiming to supply about 700,000 m³ a month to the Isfahan refinery.47 The Taleqan water transfer system was inaugurated on 3 November 2025 to supply drinking water to Tehran and Alborz.48
| Largest conveyors and transfers in the register | Length (km) | Flow as stated | Status | Award or start | Commissioned |
|---|---|---|---|---|---|
| Persian Gulf Desalination & Conveyance, line 2 | 1,550 | – | Under construction | 2025 | – |
| Persian Gulf to Isfahan Desalination and Conveyance Also: Persian Gulf to Isfahan: Sirjan to Isfahan line (800 km, Operating, in service 2025) | about 1,200 (route) | 600 million m³/year at full scheme | Under construction | 2022 | – |
| Persian Gulf Desalination & Conveyance, line 3 | 910 | – | Under construction | 2025 | – |
| Sarni Dam and Water Supply Scheme | 38 (gravity main) | 19 million m³/year drinking water | Under construction | 2015 | – |
| Kouhrang 3 Dam and Transfer Tunnel | 23.4 (main tunnel) | 255 million m³/year | Stalled | 1993 | – |
| Kouhrang Transfer Tunnels 1 and 2 | – | 23 m³/s mean (tunnel 1) | Operating | 1948 | 1955 |
| Persian Gulf Desalination & Conveyance (Kerman and Yazd) | – | not stated | Operating | 2020 | 2020 |
Register records only, not a complete national inventory.
Sources and notes
Source: the MENA Water Review major projects register. Ranked by length in km as each record states it; a figure the record gives only in another unit is shown as written and not ranked. Each name links to the project record and its sources.
Desalination
Desalination is growing from a small base. Installed capacity was about 590,500 m³ a day in 2002.1 Operational capacity is now estimated at about 1 million m³ a day, only 4% of the Gulf Cooperation Council total.49 More than 90% of plants sit in Bushehr, Hormozgan, Khuzestan and Sistan-Baluchistan.49 Pipelines also serve Isfahan, Kerman, Khorasan Razavi, South Khorasan and Yazd. In all, Gulf desalination supplies some 30 million people, a third of the population.49 State media reported 95 plants producing about 233 million m³ a year in 2023.49 Estimates differ widely: FAO’s AQUASTAT reports 3.5 km³ of desalinated water a year, its latest official figure (for 2022), about fifteen times the state-media figure.50 New plants remain modest. The Asaluyeh desalination project opened its first phase in September 2026, producing 1,000 m³ a day towards a final capacity of 5,000 m³.51 52 Officials said the plant would address 58 litres a second of Asaluyeh County’s 237 litres a second drinking-water deficit.52
| Desalination plants in the register | Capacity (m³/day) | Status | Award or start | Commissioned |
|---|---|---|---|---|
| Bandar Abbas Desalination | 100,000 | Operating | – | 2018 |
| Chabahar Desalination | 50,000 contracted | Operating | 2011 | – |
| Bushehr Desalination | 39,500 contracted | Operating | 2013 | 2016 |
Register records only, not a complete national inventory.
Sources and notes
Source: the MENA Water Review major projects register. Ranked by capacity in m³ a day as each record states it; a figure the record gives only in another unit is shown as written and not ranked. Each name links to the project record and its sources. The Persian Gulf transfer schemes, which pair plants with long pipelines, are in the conveyor table below.
Networks, sewers and irrigation
Supply networks reach almost everyone, but sewers came late. In 2011, 98% of urban and 90% of rural residents had an improved water source.2 By 2000, only 15% of cities, home to 24% of the population, treated their domestic wastewater.2 In 2001 Iran had 39 wastewater plants with a capacity of 712,000 m³ a day, serving 3.8 million people, and raw sewage was used directly for irrigation in some towns.1 A 2005 World Bank loan financed sewers and network upgrades in Rasht, Anzali, Sari and Babol.53 The Robat Karim treatment plant in Tehran Province opened in November 2025.48
On farms, dam-fed canal systems cover 1.56 million ha. The rest of the irrigated land relies on traditional canals built by farmers.1 Officials say 40% of farmland now uses modern irrigation technology, against 60% in Europe.54 Measurement lags behind. In August 2026 only about 125,000 of some 416,000 authorised farm wells had volumetric smart meters.55
| Wastewater treatment plants in the register | Capacity (m³/day) | Status | Award or start | Commissioned |
|---|---|---|---|---|
| Tabriz Wastewater Treatment Plant | about 129,600 | Operating | 1995 | 2001 |
| Parkandabad 2 Wastewater Treatment Plant | 100,000 | Under construction | 2016 | – |
| Shiraz Wastewater Treatment Plant No. 2 | 100,000 | Operating | 2010 | 2020 |
| Tehran South Wastewater Plant | not stated | Operating | 2000 | – |
Register records only, not a complete national inventory.
Sources and notes
Source: the MENA Water Review major projects register. Ranked by capacity in m³ a day as each record states it; a figure the record gives only in another unit is shown as written and not ranked. Each name links to the project record and its sources.
War damage
War has become an infrastructure risk. The energy minister blamed part of the 2025 supply strain on damage from the 12-day war with Israel in June.3
The 2026 war brought desalination into the line of fire. On 7 March 2026 Iran’s foreign minister accused the United States of striking a desalination plant on Qeshm Island, cutting water to 30 villages. The United States and Israel denied it.49 56 The next day Bahrain said an Iranian drone had damaged one of its desalination plants;56 the same day Stars and Stripes reported Iran’s foreign minister, Abbas Araghchi, calling the strike retaliation for the US attack.57 By 28 April, according to the Arab Center Washington DC, Iran had denied attacking the desalination plants in Bahrain and Kuwait and blamed Israel.49 On 13 March President Trump threatened to destroy Iran’s power and desalination plants, and Iran later threatened the Gulf’s water infrastructure.49 58
In June Iranian authorities said US strikes had destroyed two reservoirs in Sirik County serving more than 20,000 people.59 In July Iranian officials said US strikes had hit desalination plants on the Hormozgan coast, and that the strike on the plant in Bunji village, in Jask county, cut off water to 10,000 people;60 a provincial water official put them in 20 villages.61 Kuwait said Iranian attacks hit its power and desalination plants on consecutive nights.61 62 Iranian media and officials reported that a wastewater treatment plant in Bandar Abbas was also hit.60 By August, UNICEF had delivered water and sanitation equipment to nine war-affected provinces. The supplies included 26 solar-powered disinfection systems.63
Dams and reservoirs
| Largest dams: FAO AQUASTAT inventory, with two Karun dams added | River | Completed | Storage (million m³) |
|---|---|---|---|
| Karkheh | Karkheh | 2001 | 5,575 |
| Gotvand Olya | Karun | 2012 | 4,500 |
| Karoun 1 | Karoun | 1976 | 3,139 |
| Karoun 3 | Karoun | 2004 | 2,970 |
| Dez | Dez | 1962 | 2,856 |
| Karun 4 | Karun | 2010 | 2,279 |
| Main river | Dams in the inventory · storage | Largest reservoir |
|---|---|---|
| Shatt al-Arab (Arvand Rud) | none in the inventory | – |
| Karun | 5 · 13,118 MCM | Gotvand Olya (2012), 4,500 MCM |
| Helmand | 1 · 660 MCM | Chahnime, 660 MCM |
| Qezel Owzan | 1 · 1,800 MCM | Sefidroud (1961), 1,800 MCM |
| Karkheh | 1 · 5,575 MCM | Karkheh (2001), 5,575 MCM |
| Aras | 1 · 1,350 MCM | Aras, 1,350 MCM |
| Hari Rud | 1 · 1,250 MCM | Dousti, 1,250 MCM |
| Zarineh Rud | 1 · 650 MCM | Boukan (1971), 650 MCM |
| Sirwan (Gaveh Rud) | 1 · 550 MCM | Gavoshan, 550 MCM |
| Mand | none in the inventory | – |
Sources and notes
Sources: FAO AQUASTAT regional dam inventories (CC BY 4.0), which list large dams with a published capacity and can lag recent construction; the MENA Water Review major projects register, where each record cites its source on the project page. The database follows large contracted projects, not the whole asset base. Dam capacities are shown to one decimal where the record has a fraction. In the table by river, a dam is counted against the river its inventory record names, with French, Arabic, Persian and Turkish spellings of the same river treated as one; a record that gives no river is matched by its coordinates to the nearest river reach, so an unnamed dam on a tributary close to a main stem can be counted against the main stem. Records that give neither a river nor usable coordinates cannot be matched, so some rivers show fewer dams than they have. The rivers are the main rivers given under Water resources. For Iran, the inventory does not include two large Karun dams that are in the projects register: Gotvand Olya (4,500 million m³, completed in 2012) and Karun 4 (2,279 million m³, completed in 2010). They are added to the table and to the Karun row, but not to the tiles; capacities are the owner’s (IWPCO) as recorded in the register, and the completion years follow USIP and UN-ESCWA.24 64 The Karun row adds Gotvand Olya and Karun 4, which the AQUASTAT inventory does not include. The inventory’s 1,250 MCM for Doosti (Dousti) is its recorded capacity; Shared waters cites the dam’s effective capacity of 980 MCM from a 2026 study.
Water quality
Salinity follows the diversions. On the Karkheh, conductivity at Hamidiyeh rose from about 600 µS/cm in 1988 to 2,500 µS/cm in 2002. Irrigation return flows and sewage drove the rise.64 The Gotvand Dam on the Karun, completed in 2012, was built on salt beds that made its reservoir water unfit for irrigation.24 At Sayhan on the Shatt al-Arab, dissolved solids averaged 2,408 mg/L in 2011, against an FAO irrigation guideline of less than 450.64 The delta held about 18 million date palms in the 1970s, and more than 80% were gone three decades later.64
Soils and aquifers carry the long-term damage. FAO put the area affected by salinity and waterlogging at about 15.5 million ha, 9.4% of the country.1 Wells in the Tehran–Karaj aquifer supply up to 80% of the water for more than 18 million people. Between 2007 and 2018 their nitrate ranged from about 6 to 150 mg/L, up to three times the drinking standard.65 Lake Urmia’s exposed bed now produces aerosols that harm human health.66
The 2026 war
The 2026 war added new contamination. Strikes on Tehran’s oil facilities on 7 March contaminated drainage and raised alarms about surface water and groundwater.67
The reported indicators
Drinking water services
Share of the population, %
On the latest values each country reports for SDG indicator 6.3.1, Iran’s 26% (2024) ranks 16th of the 17 countries covered here that report it; years differ by country. The regional comparison is in the wastewater and reuse dashboard.
Sources and notes
Sources: WHO/UNICEF Joint Monitoring Programme via the World Bank; SDG 6.3.1 and 6.3.2 from the UN Statistics Division SDG database, retrieved September 2026. Safely managed drinking water means an improved source on the premises, available when needed and free from faecal and priority chemical contamination. SDG 6.3.2 rests on each country’s own monitoring network, so a high share can mean few water bodies were assessed, and values move when methods change between reporting rounds.
Governance & institutions
Three bodies share the water file. The Ministry of Energy manages water resources and large works such as dams and main canals.1 The Ministry of Agriculture handles tertiary canals, on-farm works and crops, and the Department of the Environment sets environmental policy.1 The ministry that supplies bulk water is therefore separate from the one whose sector uses most of it. Irrigation operation and maintenance runs through 19 companies, 49% owned by the Ministry of Energy and 51% private.1 The Iran Water Resources Management Company publishes national reservoir data.45
In the cities, water and sewerage companies set up in the early 1990s have some administrative and financial autonomy.53 Regional water boards handle bulk works such as reservoirs, transmission and treatment. The National Water and Wastewater Engineering Company coordinates the urban utilities.53
Law and water rights
All water bodies are public property, and the government is responsible for managing them.1 The first water law after the revolution, approved in 1982, gives the Ministry of Energy power to allocate water and permit its use.1 Rights differ by source. Surface water rights pass with the land, groundwater is mainly private and traded, and qanats are held in shared ownership.1 Food policy adds pressure. Iranian law requires 85% of domestic food to be produced at home, a Kharazmi University expert notes.3
Pricing and reform
Cheap water and energy add to the problem. The Targeted Subsidies Law, enacted in 2009, has been implemented since December 2010.2 Before it, indirect subsidies reached about US$77 billion in 2007, or 27% of GDP.2 Officials now describe water as an economic commodity.42 In November 2025 the energy minister said high-consuming urban users would be penalised.3 The ministry has also invited local and foreign investors to co-finance water and energy projects through public-private partnerships.81
Volumetric delivery to farms is the long-promised fix. The Ministry of Agriculture says at least 15 annual laws and medium-term programmes have required it of the Ministry of Energy, with poor results for surface water.55 In August 2026 a guideline under Article 40 of the Seventh Development Plan Law had been drafted and was to be announced soon; it would gradually transfer part of the Ministry of Energy’s agricultural water-management responsibilities to agricultural operators and organisations.55 The energy ministry’s SAMAB water database is being linked to the farm zoning system, to set water volumes per farmer.82 In October 2025 the government adopted a National Climate Change Management Plan to build resilience in water and farming.10
Key sector institutions
- Ministry of Energy (water & wastewater affairs)Lead ministry
Lead ministry for water resources, supply and wastewater.
moe.gov.ir (website, opens in a new tab) - Iran Water Resources Management Co.Resources holding company (Ministry of Energy)
The Ministry of Energy's water-resources holding company and its agent in implementing the water law and managing water resources.
wrm.ir (website, opens in a new tab) - National Water & Wastewater Engineering Co. (Abfa)Utility holding
Holding company for the provincial water and wastewater companies.
nww.ir (website, opens in a new tab) - Provincial Water & Wastewater Companies (Abfa)Urban utilities
Urban water and sewerage companies, set up in the early 1990s with some administrative and financial autonomy and coordinated by the national engineering company.
tpww.ir (website, opens in a new tab) - Ministry of Agriculture-JahadIrrigation
Handles tertiary canals, on-farm works and crops, in the sector that uses most of Iran's water.
maj.ir (website, opens in a new tab) - Department of EnvironmentWater quality
Sets environmental policy, including for water quality.
doe.ir (website, opens in a new tab)
Sources and notes
Institutions compiled from the FAO AQUASTAT institutions database and national sources. Responsibility lines summarise this report and the organisations directory. Website links are the official sites verified for that directory; for a group of bodies, the link is one member’s site.
Challenges & outlook
The strain is now visible from space, in the subsiding plains and the shrinking Lake Urmia set out above. Agriculture is the lever. Shrinking irrigated farming would ease both problems. It would also touch farm jobs: Kaveh Madani of the UN University says that under sanctions Iran cannot diversify rural employment, so water keeps going to agriculture for fear that threatening farm jobs could cause protests.3
The cities are already testing the limits, as Tehran’s reservoirs showed in 2025 (see Infrastructure). Water has also become a trigger for unrest and a target in war. Protesting farmers in Isfahan destroyed three pumping stations and damaged the main pipeline to Yazd in 2025.25 The damage from the 2026 war is set out under Infrastructure. The open question is whether adjustment comes by plan, through pricing, farmland retirement and reuse. The alternative is adjustment by force, through subsidence, salt and migration.
Sources
82 references
Principal sources: Iran Water Resources Management Co. public data; Urmia programme reporting; World Weather Attribution (2021–25 droughts); FAO AQUASTAT. Figures approximate.
- FAO AQUASTAT, country profile: Iran (Islamic Republic of) (2008 edition).
- Islamic Republic of Iran, Department of Environment, National Climate Change Office, Third National Communication to the UNFCCC, December 2017.
- Al Jazeera, “As the dams feeding Tehran run dry, Iran struggles with a dire water crisis”, 12 November 2025.
- Haghshenas Haghighi, M. and Motagh, M. (2024), national land subsidence survey of Iran, Science Advances 10, doi:10.1126/sciadv.adk3039.
- NASA Earth Observatory, “Lake Urmia shrivels again”, 10 October 2023.
- Tehran Times, “President inaugurates project to transfer seawater to central plateau”, 6 December 2025.
- UNESCO World Heritage Centre, The Persian Qanat, inscribed 2016 (archived copy).
- De Planhol, X. (2011), “KĀRIZ v. Kārēz in the late 20th century and their prospects”, Encyclopaedia Iranica.
- ICOMOS, evaluation of The Persian Qanat, UNESCO document WHC-16/40.COM/INF.8B1, p. 94.
- World Weather Attribution, “Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin”, 21 November 2025.
- CNN, report on Iran’s driest autumn in 50 years, 16 November 2025 (archived copy).
- World Bank, World Development Indicators and country water-sector reporting. data.worldbank.org.
- FAO, AQUASTAT — Global Information System on Water and Agriculture: country water resources, withdrawals by sector and dam register. fao.org/aquastat. Latest country values as compiled at build.
- World Resources Institute, Aqueduct 4.0 Water Risk Atlas (2023) — the sub-basin risk, stress and groundwater-decline layers on the interactive maps. wri.org/aqueduct. Country baseline water-stress category: Aqueduct 4.0 Current and Future Country Rankings (16 August 2023), indicator bws, all sectors, 1979–2019.
- White, C. (2014), “Understanding water scarcity: definitions and measurements”, in Grafton, Wyrwoll, White and Allendes (eds), Global Water: Issues and Insights, ANU Press, p. 161, giving the Falkenmark et al. (1989) thresholds.
- Tehran Times, “Rainfall drops 41% this water year, raising reservoir crisis concerns”, 9 March 2025 (official figures).
- Tehran Times, “Power cuts, water shortage amid scorching summer”, 28 July 2025.
- World Weather Attribution, “Human-induced climate change compounded by socio-economic water stressors increased severity of drought in Syria, Iraq and Iran”, 8 November 2023.
- World Bank, Climate Change Knowledge Portal, CMIP6 multi-model ensemble median against 1995–2014, retrieved September 2026.
- Washington Institute, “How mangled dam diplomacy is shaping Iraq’s water crisis”, November 2020.
- Multi-sensor InSAR study of Tehran, Remote Sensing of Environment 221 (2019), doi:10.1016/j.rse.2018.11.003.
- Goorabi, A. et al. (2020), subsidence of the Isfahan metropolitan area, Journal of Arid Environments 181, doi:10.1016/j.jaridenv.2020.104238.
- Groundwater overdraft and subsidence at Rafsanjan, Pakistan Journal of Biological Sciences (2008), doi:10.3923/pjbs.2008.265.269.
- US Institute of Peace, The Iran Primer, “Explainer: Iran’s water bankruptcy”, 5 December 2021.
- Iran International, report on the Zayandeh Rud and Isfahan’s farmers, April 2025.
- Science, “After revival, Iran’s great salt lake faces new peril”, 29 April 2021.
- Shahbazi et al. (2025), drivers of Lake Urmia’s inflow decline, Scientific Reports, doi:10.1038/s41598-025-21735-7.
- Iran International, report on Lake Urmia’s record low, 20 September 2024.
- Tehran Times, “Lake Urmia’s level increases by 120 cm in 7 months”, 23 April 2026 (official figures).
- FAO. 2026. AQUASTAT Core Database. Food and Agriculture Organization of the United Nations. Database accessed on 2026/10/20. Variable “SDG 6.4.2. Water Stress” (indicator 6.4.2, level of water stress: freshwater withdrawal as a proportion of available freshwater resources; FAO is the custodian agency), read from the AQUASTAT Dissemination System.
- Taadol, interview with the deputy agriculture minister on limiting rice cultivation (Persian), 18 August 2025.
- Noori, R. and others (2021), “Anthropogenic depletion of Iran’s aquifers”, Proceedings of the National Academy of Sciences 118(25), 14 June 2021.
- Donya-e-Eqtesad, interview with Majid Anjafi, deputy minister of agriculture, on the fall in water allocated to farming (Persian), 9 November 2025.
- Taadol (citing ISNA), report on the blocking of 28,000 illegal wells (Persian), 18 May 2026.
- Circle of Blue (AFP), “Iranian president says country is on brink of dire water crisis”, 31 July 2025.
- FAO. 2026. AQUASTAT Core Database. Food and Agriculture Organization of the United Nations. Database accessed on 2026/10/20. Values for the variables named in the text, read from the AQUASTAT Dissemination System with FAO’s flag on each: official value, estimate (calculated or identified from official values or from an AQUASTAT estimation) or imputed (carried forward or interpolated).
- Tehran Times, “Iran aims to equip 70,000 hectares of farmland with modern irrigation systems”, 16 April 2025.
- Tehran Times, “Infrastructures for cultivation pattern plan implementation set up in all provinces”, 31 January 2023.
- Mehr News, report on the ban on rice cultivation in Khuzestan (Persian), 12 May 2025.
- Mehr News, report on the ban on rice cultivation in the plains of eastern Kermanshah (Persian), 22 January 2026.
- Akbarzadeh, A. and others (2023), “Municipal wastewater treatment in Iran: current situation, barriers and future policies”, Journal of Advances in Environmental Health Research 11(1), 60–71 (abstract read).
- Tehran Times, “PBO head outlines coastal, water projects under new development plan”, 27 August 2025.
- Tehran Times, “Water inflow into Iranian dams drop 40% amid dry autumn”, 9 November 2025 (Energy Ministry figures).
- The Water Diplomat, “Threat of day zero in Tehran”, November 2025.
- Tehran Times, “Major dams 41% full as Iran enters final month of winter”, 23 February 2026 (official figures).
- Eurasia Review, “Inaugurated major seawater transfer project to central Iran”, 7 December 2025.
- Tehran Times, “Isfahan refinery begins using seawater, secures 700,000 cubic meters monthly”, 23 July 2025.
- Tehran Times, “Pezeshkian inaugurates 4 key water, power projects across Iran”, 3 November 2025.
- Arab Center Washington DC, “War on Iran: the dangers of attacking water desalination plants in the Gulf”, 28 April 2026.
- FAO AQUASTAT, country fact sheet: Iran (Islamic Republic of), consulted 12 October 2026.
- Mehr News Agency, “Iran inaugurates major desalination plants despite US threats”, 9 September 2026 (official claims).
- Tehran Times, “1,000-cubic meter desalination plant goes operational in Asaluyeh”, 8 September 2026.
- World Bank, Project Appraisal Document: Northern Cities Water Supply and Sanitation Project (P076884), 28 April 2005.
- Tehran Times, “40% of Iran’s agricultural land equipped with modern irrigation”, 6 January 2026.
- Tehran Times, “25% of agricultural water wells equipped with smart meters”, 11 August 2026.
- Al Jazeera, “Bahrain says water desalination plant damaged in Iranian drone attack”, 8 March 2026.
- Renfroe, S., Stars and Stripes, “Bahrain desalination plant struck as water infrastructure becomes latest front in Iran war”, 8 March 2026.
- The Guardian, report on Iran’s threat to Gulf water facilities, 23 March 2026.
- Al Jazeera, “US bombs Iran’s water facilities: why that’s so significant”, 10 June 2026.
- Al Jazeera, “What are civilian sites in international law, and where have the US and Iran hit?”, 20 July 2026.
- Middle East Eye, report on the strikes on Bunji and Kuwait, 18 July 2026.
- War on the Rocks, “Cheap drones, dry taps: the Iran war opens a new era of water infrastructure risk”, 14 August 2026.
- Tehran Times, “Sanitation services, safe water restored in war-affected provinces”, 2 September 2026.
- UN-ESCWA and BGR (2013), Inventory of Shared Water Resources in Western Asia, chapter 5: Shatt al Arab, Karkheh and Karun Rivers.
- Nitrate in the Tehran–Karaj aquifer, Scientific Reports (2024), doi:10.1038/s41598-024-58290-6.
- Parsinejad, M. et al. (2022), synthesis of research on Lake Urmia, Science of the Total Environment 832, doi:10.1016/j.scitotenv.2022.155055.
- Carnegie Endowment for International Peace, on the environmental harms of strikes on Iran’s energy infrastructure, 28 July 2026.
- Treaty concerning the State Frontier and Neighbourly Relations between Iran and Iraq, Baghdad, 13 June 1975, UN Treaty Series vol. 1017.
- UN-ESCWA and BGR (2013), Inventory of Shared Water Resources in Western Asia, chapter 4: Shared Tributaries of the Tigris.
- Middle East Eye, report on Iranian cuts to the Sirwan and Little Zab, 3 September 2020.
- Voice of America, “Afghan leader demands Iranian oil in exchange for river water”, 24 March 2021.
- International Water Law Project, “The Helmand River and the Afghan–Iranian Treaty of 1973”, 23 July 2015.
- The Guardian, report on the Kamal Khan dam project and the Helmand, 22 March 2017.
- Lowy Institute, The Interpreter, on the Afghanistan–Iran water treaty dispute, 14 October 2020.
- Al Jazeera, “What caused deadly Afghan–Iran border clashes?”, 30 May 2023.
- DW, “What is the Iran–Taliban water conflict all about?”, 1 June 2023.
- Water allocation in the Harirud basin, Scientific Reports (2026), doi:10.1038/s41598-026-43368-0.
- Tehran Times, “Iran calls on Afghanistan to honor water rights in border river”, 3 January 2025.
- Iran International, report on the Pashdan Dam and Mashhad’s supply, 22 August 2025.
- KabulNow, “Iran seeks talks with Afghanistan over water rights from the Harirud River”, 7 January 2026.
- Tehran Times, “1,000 water, power projects to be launched by March 2026: energy minister”, 28 July 2025.
- Tehran Times, “Agriculture, energy ministries’ systems connected for smart water management”, 8 August 2026.
Numbered references are linked from the superscript markers in the text. Figures without a marker come from the sources above as compiled in the site methodology.