Water in Turkey

Turkey is a high, mountainous country, with plentiful rainfall on the coasts and little inland.^1 2 It lies upstream on the Euphrates and Tigris, which it treats as transboundary rivers under its sovereignty, while Syria and Iraq describe them as international rivers.³ Irrigation accounts for most of the water Turkey uses.⁴ A National Water Plan for 2026 to 2035 sets targets for network losses, daily use per person and irrigation efficiency.^5 6

Istanbul has long brought its water from far away. In the late fourth century, the channel of Valens carried water 215 km from ThraceThrace An ancient and modern region of the south-eastern Balkans, shared today by Bulgaria, Greece and Turkey. Turkey’s European territory lies within it. Source: Thrace, Encyclopædia Britannica to Constantinople, and the city’s supply network stretched to 592 km of channels, more than the 520 km that supplied Rome.⁷ The water was stored in at least 160 cisterns, among them the Basilica Cistern, built under Justinian I.^8 9 Between 1554 and 1563, the architect SinanSinan The most celebrated Ottoman architect (born about 1490, died 1588), who served the Ottoman court and above all Sultan Süleyman I. His mosques and other buildings set the pattern for later Turkish religious and civic architecture. Source: Sinan, Encyclopædia Britannica built the Kırkçeşme system for Süleyman the Magnificent.⁷ In the twentieth century, the state turned to the great rivers. On the Euphrates, Keban was finished in 1974, and the Atatürk reservoir was filled between 1990 and 1992.^3 2 State Hydraulic Works now counts 861 dams in operation across Turkey.⁴

More storage has not ended scarcity. Usable water per person fell from 1,652 m³ in 2000 to 1,346 m³ in 2020.⁴ In the Konya closed basin, groundwater levels now fall an estimated 4 to 5 metres a year.¹⁰ In 2025, a drought that one expert called the harshest in about fifty years brought Istanbul’s reservoirs down from about 80% full in early April to roughly 25% by mid-October.¹¹ Downstream, Turkey and Iraq signed a financing mechanism in November 2025 under which Turkish companies build Iraqi water projects, paid for through Iraqi oil sales.¹² Baghdad still accuses Ankara of restricting flows, while Turkey says Iraq’s infrastructure is outdated and wasteful.¹³

One interactive map of Turkey'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 Turkey 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.

Turkey is high and mountainous. Its average altitude is about 1,141 m, and mountain chains run parallel to the northern and southern coasts.¹ The country covers about 783,560 km², about 3% of it in Europe.² It has 2,875 km of land borders and 8,333 km of sea borders, which leaves it exposed to rising seas.¹ The Euphrates runs 1,263 km and the Tigris 512 km within Turkey.⁴

Rainfall

Rain is plentiful on the coasts and scarce inland. The Black Sea coast receives the most, and Central Anatolia the least, at 200–600 mm a year.² In 2024 Rize was the wettest province, with 1,869.8 mm, and Kırıkkale the driest, with 316.1 mm.¹⁹ The meteorological service puts the national average at 573.4 mm for 1991–2020.²⁰ Most rain falls in winter and spring. Every region except the Black Sea faces a summer water shortage.¹ In the south-east, which gets almost no summer rain, evaporation can exceed 2,000 mm a year.²

Dry years hit hard. In 2025 rainfall averaged 414.9 mm, 27.6% below normal, and the drought hurt water resources, farming and energy.²⁰ Only the Black Sea coasts, the north and east of Eastern Anatolia and the Hakkâri area escaped drought on the 12-month index.²⁰ Station records show annual rainfall rising along the coasts but falling in almost all inland regions. The national communication reads the inland decline as a possible early sign of drought.¹

In the World Bank Climate Change Knowledge Portal’s ERA5 reanalysis, averaged over the whole of Turkey, about 702 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 a national average of 573.4 mm for 1991–2020 from the meteorological service). About 35% of the rain falls in December, January and March. Average rainfall in 1993–2022 was about 4% lower than in 1951–1980, and single years swing widely around that.

Heat

Temperatures follow altitude and the sea. Mean annual temperature is 18–20 °C on the south coast, 14–15 °C on the west coast and 4–19 °C inland.² On 25 July 2025 Silopi recorded 50.5 °C, a national record.²⁰ In 2024 the national mean reached 15.6 °C, 1.7 °C above the 1991–2020 average and the highest in 54 years.¹⁹ July 2025 was the hottest July in 55 years. Every year since 2007, except 2011, has been warmer than normal.²⁰

The same reanalysis gives a mean temperature of 11.6 °C for 1991–2020 and a warming of about 0.43 °C a decade over 1971–2022. Station records and national reports use other sources and periods, so their warming rates can differ.

Projections

The meteorological service’s regional model projects average warming of 1.5–2.6 °C over 2016–2099 under a moderate scenario. Under high emissions the range is 2.5–3.7 °C.¹ Rain shifts with the seasons. In the moderate scenario, winter rain rises by about 10% on the coasts, while summer rain falls by up to 40% outside the Aegean, Marmara and Black Sea coasts.¹ Under high emissions, autumn rain could fall by 40–50% almost everywhere except the Marmara coasts.¹ The World Bank’s CMIP6 ensemble points the same way, with annual rainfall about 13% lower by 2080–2099 under high emissions (see the table below).²¹

Projected change for Turkey

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.

Turkey is water-rich by regional standards. FAO put internal renewable resources at 227 billion m³ a year. About 186 billion is surface water and 69 billion groundwater, with 28 billion counted in both.² Most rivers rise inside the country, which has 320 natural lakes; its dams are covered under Infrastructure.^2 4 Turkey supplies about 90% of the Euphrates’ annual flow. It contributes 38% directly to the main Tigris and another 11% through tributaries that join it in Iraq.² State Hydraulic Works puts exploitable groundwater at 18 billion m³ a year.⁴

Turkey receives about 450 billion m³ of precipitation a year, but State Hydraulic Works (DSİ) counts only 112 billion m³ as net usable. Usable water per person fell from 1,652 m³ in 2000 to 1,544 m³ in 2009 and 1,346 m³ in 2020.⁴

Konya’s sinking plain

Konya's closed basin is sinking, literally, under groundwater-fed agriculture. The disaster agency AFAD has documented 684 sinkholes across Konya, Karaman and Aksaray.¹⁶ A Konya geologist estimates that groundwater levels now fall 4–5 metres a year, against half a metre in the early 2000s,¹⁰ and satellite radar measured subsidence of 5–10 cm a year in the Karapınar area in 2019–2020, reaching 16 cm a year.²²

Supply by source

The main rivers

The table ranks the rivers of Turkey 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.

The dams on these rivers, from the FAO AQUASTAT inventory, are listed river by river under Infrastructure.

On State Hydraulic Works’ undated count, Turkey uses about 57 billion m³ of water: 44 billion for irrigation, some 77% of the total, and 13 billion for drinking water and industry.⁴ FAO AQUASTAT’s total water withdrawal for 2022, a different measure, is under Use by sector below.

Irrigation drives the demand. DSİ calculates that 8.5 million ha could be irrigated with existing water, and some 7.03 million ha had been opened to irrigation by 2025,²³ up from 6.65 million ha at the end of 2019.⁴

GAP: targets and delivery

The Southeastern Anatolia Project took its name in 1977, when the Lower Euphrates and Tigris plans were merged.²⁴ Its master plan, completed in 1989, called for 22 dams, 19 hydropower plants and irrigation on about 1.7 million ha. The 2002 regional plan raised the target to about 1.8 million ha.²⁴ Keban, finished in 1974, predates the project. Karakaya followed in 1987 as GAP’s first dam, then the Atatürk Dam (see Infrastructure).³

Energy came faster than water. By 2024, 18 of the 22 dams and 14 of the 19 power plants were complete, and GAP plants had generated 548 billion kWh.²⁴ Irrigation lags far behind. By the end of 2024, 675,250 ha had been opened to irrigation. That is 60.8% of the 1.11 million ha in the 2024–2028 action plan, but only about 37.5% of the long-term 1.8 million ha target. Just 11,331 ha were added in 2024.²⁴ The largest scheme with nothing yet completed, the Silvan gravity system, covers 128,897 ha.²⁴

Use by sector

Withdrawals over time

FAO’s AQUASTAT estimates put Turkey’s freshwater withdrawals at 31.6 billion m³ in 1992 and 64.5 billion m³ in 2022. Agriculture’s share of the total moved from 76% in 1994 to 87% in 2022.

Irrigation is by far the largest use. FAO records 46.81 billion m³ withdrawn for irrigation in 2022, an official value, and 9.32 billion m³ for aquaculture, which together make the agricultural withdrawal of 56.13 billion m³.²⁶ The World Bank estimates that 95% of exploitable groundwater is already used.²⁷

Who runs the schemes

DSİ builds the schemes and then transfers their operation. The table shows where the 3.08 million ha transferred stood at the end of 2025; the number of associations is the 181 left after the mergers described under Governance. Associations set their own fees but not below a floor approved by the minister; for 2024 the floor ran, by crop and scheme group, from 79 to 292 lira per decare for cereals and from 276 to 1,041 for rice and sugar cane. Irrigation from licensed groundwater inside a scheme pays 45 lira per decare.³⁰

Area and methods

The ministry counted 4.91 million ha of DSİ irrigation and 2.29 million ha of other irrigation in 2024.³¹ DSİ reported a gross DSİ-built irrigated area of 4,985,971 ha at the end of 2025, against a target of 5,032,797 ha, an irrigation ratio of 68% and an efficiency of 52% in DSİ-run areas; its plan for 2024–2028 aims at 72% and 56%.²⁸ In 2018 the World Bank put surface methods at almost 90% of irrigation;³² Daily Sabah, relaying DSİ, reported that 36% of DSİ systems were modern piped systems at the end of 2024.²³ The World Bank’s status report of January 2025 recorded 23,280 ha with improved service under the register’s Irrigation Modernization Project, against a target of 50,764 ha.³³

Wells, crops and charging

A DSİ licence is required for wells, except hand-dug wells and those shallower than set depths, under the regulation of 1961.³⁴ DSİ had completed hydrogeological studies in 13 basins by the end of 2025, and its plan lists unlicensed use as a gap in Law 167, the conversion of groundwater irrigation to surface water where levels are below the safe reserve, and pricing by volume; it had installed 56,550 meters at 377 facilities by the end of 2024.^28 23 These are plan measures, not enacted rules. The 2024 production-planning booklet gives farmers who grow planned crops on irrigated land in basins declared water-constrained a further 50% of fertiliser support; it is an incentive, not a ban.³⁵

Treated wastewater

Reuse rates are under Infrastructure. FAO reports 45.4 million m³ of treated wastewater used for irrigation, last reported for 2018.²⁶ The World Bank’s Water Circularity and Efficiency Improvement Project, with US$350 million for irrigation modernisation, required a feasibility study of treated-wastewater reuse in irrigation by January 2025;³⁶ its outcome was not found. The register lists the İzmir wastewater reuse scheme, which supplies farmers through an irrigation cooperative; more are on the Agriculture & Food hub.

Turkey has 861 dams in operation, on State Hydraulic Works’ undated count. The largest reservoirs are Atatürk at 817 km², Keban at 675 km² and Ilısu at 313 km².⁴ State Hydraulic Works (DSİ) has built hundreds of dams. By 2006, 208 large dams and 579 dams in all were in service, and the large dams alone held almost 157 billion m³.² Atatürk, filled between 1990 and 1992 with 48.7 billion m³ of storage, is among the ten largest dams in the world.² Its reservoir can hold the Euphrates’ entire annual discharge.³ Its water reaches the Harran Plain through the Şanlıurfa tunnels. They run 26.4 km, with a diameter of 7.62 m, and carry about 328 m³/s, a third of the Euphrates’ flow.²

Tracked projects

Open the project database for Turkey

Earthquake damage

The February 2023 earthquakes struck a region that holds major dams and irrigation schemes. DSİ estimated damage to its facilities at about 19.5 billion lira, or US$1.03 billion.³⁷ Irrigation facilities covering 923,976 ha and 39,113 wells were damaged.³⁷ Sultansuyu Dam in Malatya was so badly damaged that it must be rebuilt, and Reyhanlı Dam in Hatay can operate again only after reinforcement.³⁷ Losses and theft already took 36.8% of water in the 11 affected provinces, above the national average given under Cities and wastewater.³⁷

Irrigation networks

Canals are giving way to pipes. In DSİ schemes, 35% of systems are conventional canals, 40% canalettes and 25% closed pipes. In 2018 the government projected that the piped share would rise to 45–50%.¹ Efficiency has been low. In 2001 it was 38% in schemes run by DSİ and 48% in schemes handed to farmers.² DSİ has also built 20,716 km of drainage canals.² The Water Efficiency Action Plan for 2023–2033 aims to modernise 1.3 million ha at an estimated US$6.5 billion.²⁷ A World Bank project covering 50,764 ha had completed 15,280 ha and 694.54 km of network by 2024.²⁷

Cities and wastewater

Urban demand keeps climbing. In 2000 Istanbul’s 11 million people used 600 million m³ a year. With 16 million residents today, that figure has nearly doubled, an academic told Hürriyet Daily News. Istanbul’s reservoirs fell to 29.92% in November 2024, from 82.62% in April.³⁸ Treatment has spread quickly. In FAO’s 2008 profile, 1,327 of 3,215 municipalities had their own sewerage, and about 60% of the population was connected to a treatment plant.² The municipal population served by treatment plants reached about 56 million by 2016, TurkStat data show.¹ Before the 2023 earthquakes, losses and theft took 35.4% of water nationally, the government’s March 2023 recovery assessment reported, without giving a year for the figure;³⁷ the National Water Plan targets drinking-water network losses of 25% by 2030 (see Governance). Treated wastewater plays almost no part in supply yet. Reuse stood at 3.2% in 2021, against targets of 5% for 2023 and 15% for 2030.³⁹

Dams and reservoirs

The Euphrates leaves Turkey with low salinity. It averaged about 237 ppm salinity in Turkey in 2002–03, and 248 ppm at Jarablus on the Syrian border.³ Its rise further downstream is covered on the Syria page. The Tigris is under more pressure inside Turkey, where large towns discharge untreated domestic and industrial wastewater into it. In 2008 total phosphorus exceeded 0.075 mg/L at most sampling sites, a sign of the onset of eutrophication. Dissolved oxygen is depleted at Diyarbakır.⁴⁷ Syria and Iraq have alleged that Turkey releases polluted water across the border, which Turkey rejects.⁴⁸

The Ergene and the Sea of Marmara

In the north-west, about 2,600 industrial plants were reported in 2018 to be discharging into the Ergene in Thrace, a basin of more than a million people, and experts ranked it as Turkey’s fourth most polluted river.⁴⁹ Municipal sampling at Uzunköprü placed it in pollution class III of IV, with total nitrogen at 12.58 mg/L against a pollution threshold of 1.5.⁵⁰ Cancer registrations at Trakya University rose from 1,739 in 2010 to 2,150 in 2017. The head of oncology cautioned against a definite link to pollution.⁴⁹

In June 2021 mucilage spread across the Sea of Marmara. The environment minister announced a 22-point action plan, including protected status for the entire 11,350 km² sea by the end of the year.³⁹ At the time 53% of the region’s wastewater received only preliminary treatment. The plan aimed to convert all wastewater treatment plants in the region to advanced biological treatment within three years; the minister said scientists considered a 40% cut in nitrogen necessary to solve the problem.³⁹ That month officials said a phosphate fertiliser plant in Bandırma had been fined TL 96,561 after yellow sulphur material stored at its coastal facility was thrown into Bandırma Bay; the company said no fine had been imposed for polluting the sea.⁵¹

The reported indicators

On the latest values each country reports for SDG indicator 6.3.1, Turkey’s 63% (2024) ranks joint 11th of the 17 countries covered here that report it; years differ by country. The regional comparison is in the wastewater and reuse dashboard.

About 35% of Turkey’s water resources are generated in its transboundary basins, the foreign ministry says: the Meriç, Kura–Aras, Çoruh, Euphrates–Tigris and Asi (Orontes). Turkey stresses that it is a downstream as well as an upstream country.⁵²

A position fixed in law

Turkey treats the Euphrates and Tigris as transboundary rivers under its sovereignty while they flow through its territory, and rejects the idea of “sharing” their waters. Syria and Iraq describe them as international rivers.³ Turkey also treats the two as a single system. In 1984 it submitted a three-stage plan for their use on that basis, and the foreign ministry says Syria and Iraq did not respond.⁴⁸ Its stated principles are equitable, reasonable and optimal use, no significant harm, and no role for third parties.⁵²

That position shaped Turkey’s vote on the UN Watercourses Convention. When the General Assembly adopted it on 21 May 1997, by 103 votes to 3, Turkey voted against, with China and Burundi.⁵³ Its delegate objected that the text did not refer to sovereignty over national reaches of a river. Equitable use, he argued, should prevail over the duty not to cause harm. The convention, he said, would have no legal effect in Turkey.⁵³ Turkey has not acceded to it.⁵⁴

Protocols and committees

The 1946 treaty with Iraq addressed flow regulation, flow data and prior notification.⁴⁷ A 1980 protocol created a Joint Technical Committee, which Syria joined in 1983. It held sixteen meetings and is no longer functional.^3 48 On 17 July 1987 Turkey signed a protocol with Syria. It undertook to release a yearly average of more than 500 m³/s at the border while the Atatürk reservoir filled and until a final allocation. It would make up any monthly shortfall the following month.⁴⁸ Filling Atatürk in early 1990 temporarily interrupted the flow.⁴⁸

The Ilısu Dam

Ilısu followed on the Tigris. Its design was finalised in 1982, and construction began in August 2006. Work stopped two years later, when European governments withdrew export-credit support after a campaign by environmental groups.⁴⁷ The government had approved the dam in 1997. Its first turbine started in May 2020, and it reached full capacity in December 2020 with 10.6 billion m³ of storage.⁴⁵ Critics put the number of people resettled at about 50,000.⁴⁷

The Orontes, the Çoruh and the Aras

On the Orontes, Turkey and Syria signed a memorandum in December 2009 for a joint Friendship Dam, splitting its costs, and broke ground on 6 February 2011.^55 56 UN-ESCWA reported in 2013 that it was unclear whether construction was continuing. It also reported that Turkey and Syria had no agreement on allocation and had not resolved the question of Hatay province.⁵⁵ On the Çoruh, upstream of Georgia, Turkey inaugurated the 558 MW Yusufeli Dam in November 2022.⁵⁷ On the Arpaçay (Akhurian) border river with Armenia, a 525 million m³ reservoir irrigates almost 104,000 ha in both countries.⁵⁸

Iraq: from protocols to financing

On 22 April 2024, on the first visit to Iraq by a Turkish leader since 2011, the two states signed a ten-year framework on water management.⁵⁹ In July 2025 President Erdoğan agreed to raise releases into the Tigris and Euphrates to 420 m³/s.⁶⁰ On 2 November 2025 the foreign ministers signed a financing mechanism: Turkish companies build Iraqi water projects, paid through Iraqi oil sales.¹² Iraq’s foreign minister called it first-of-its-kind cooperation. Baghdad still accuses Ankara of restricting flows, while Turkey says Iraq’s infrastructure is outdated and wasteful.¹³

The record

Shared river basins

The agreements

Joint bodies

• Joint Boundary Water Commission (JBWC)Coruh · 1927 (Turkey–USSR treaty; the database gives 1973) · Georgia (formerly USSR), Turkey
• Joint Technical Committee on Regional Waters (JTCW)Euphrates-Tigris · 1980 (Syria from 1983; dissolved after 1993) · Iraq, Syria, Turkey
• Kura Araks Joint Commission (KAJC)Kura-Araks · year not recorded · Georgia, Turkey

Shared aquifers

• Evros / MeriçGreece · data limited
• Jezira Tertiary Limestone Aquifer SystemSyria · data moderate
• Leninak-Shiraks AquiferArmenia · data moderate
• Malko Tarnovo Karst waterbearing massifBulgaria · data limited
• Orestiadas SystemBulgaria, Greece · data limited
• Taurus-Zagros Mountain rangeIran, Iraq · data moderate
• Topolovgrad Massif AquiferBulgaria · data limited
• Upper JeziraIraq, Syria · data limited

State Hydraulic Works (DSİ), created in 1954 by Act No. 6200, is the main agency for water and soil planning, dams, irrigation and drainage.² Groundwater legislation of 1960 made it responsible for exploring, using and registering groundwater.² Water policy sits with the Ministry of Agriculture and Forestry. It absorbed the former Ministry of Forestry and Water Affairs and houses the General Directorate of Water Management.¹ Water user associations run many irrigation schemes. Under Law No. 7139, DSİ merged them, cutting their number from 378 to 181 in 2022.²⁷ DSİ is responsible only for conveyance networks, not for losses on farms.²⁷

Plans and targets

The National Water Plan for 2026–2035 was approved by Presidential Decision No. 11063 and published on 14 March 2026.⁵ Prepared by the Ministry of Agriculture and Forestry, it targets drinking-water network losses of 25% by 2030 and 10% by 2050.⁶ Daily use per person is to fall to 120 litres by 2030 and 100 litres by 2050.⁶ Irrigation efficiency is to reach 60% by 2030 and 65% by 2050, and industrial water recovery 30% and 50%.⁶ A National Drought Management Strategy and Action Plan was published on 31 August 2017; in 2018 the aim was drought plans for all basins by 2023.¹

Tariffs and cost recovery

Farmers pay by cropped area, not by volume. In 2001–2005 charges in large schemes averaged US$83 per hectare.² After the 2001 economic crisis, the cost of irrigation development rose sharply. Water prices did not keep pace, for political reasons, FAO noted.²

Turkey’s foreign ministry describes the country as neither rich in freshwater resources nor the richest in its region.⁵² Usable water per person has been falling (see Water resources), 2025 brought drought and record heat, and models point to hotter summers and, under high emissions, much drier autumns (see Geography & climate).¹

The National Water Plan sets the test for the next decade, with targets for network losses and irrigation efficiency by 2030 (see Governance). At home, the Konya closed basin is sinking (see Water resources). Downstream, the oil-for-water framework signed with Iraq in November 2025 ties Turkish contractors to Iraqi water projects.¹³