Water in Turkey

Turkey is the region's water tower and its most consequential upstream power. With about 1,350 m³ per person it is merely "water-stressed" by local standards, but its choices cascade south. The dams on the Tigris and Euphrates, among them Keban, Atatürk and Ilısu, set the flows that Syria and Iraq live on. At home, Turkey runs a huge irrigation economy, thirsty coastal cities and Istanbul, a megacity that has flirted with "day zero" in recent drought winters. 2025 made the flirtation serious. The country's harshest drought in about fifty years dropped Istanbul's ten reservoirs from 81% full in April to roughly 25% by mid-October. Central Anatolia recorded its lowest rainfall in 65 years.¹¹

A quick-reference dashboard for Turkey: headline economy and water indicators³⁶³⁷, water stress against the scarcity thresholds, non-conventional supply, and the institutions behind the sector. The commercial picture, with buyers, deal structures and the project pipeline, is in the market brief.

One interactive map of Turkey's water, built from real geodata. Climate & drought maps the aridity gradient (WorldClim) with warming projections. The WRI Aqueduct layers, 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. Hover any sub-basin or marker for detail; sources are cited under each view.

Turkey is high and mountainous. Its average altitude is about 1,132 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 523 km within Turkey.¹

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.⁴ The meteorological service puts the national average at 573.4 mm for 1991–2020.³ 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.³ Only the Black Sea coasts, the north and east of Eastern Anatolia and the Hakkâri area escaped drought on the 12-month index.³ Istanbul felt it early. Its reservoirs fell to 29.92% in November 2024, from 82.62% in April.⁶

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.³ In 2024 the national mean reached 15.6 °C, 1.7 °C above the 1991–2020 average and the highest in 54 years.⁴ July 2025 was the hottest July in 55 years. Every year since 2007, except 2011, has been warmer than normal.³ 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

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).⁵

Rainfall and temperature in numbers

Averaged over the whole of Turkey, ERA5 reanalysis gives about 702 mm of rain a year and a mean temperature of 11.6 °C for 1991–2020. About 35% of that rain falls in December, January and March. Since 1971 the country has warmed by about 0.43 °C a decade. Average rainfall in 1993–2022 was about 4% lower than in 1951–1980, and single years swing widely around that.

Projected change

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.

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 more than 120 natural lakes and 579 artificial ones.² 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 Reliable groundwater reserves were estimated at 14 billion m³ a year.²

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. Water tables there now fall 4–5 metres a year, against half a metre in the early 2000s, and parts of the plain subside up to 10 cm annually.¹²

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.

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 Turkey 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. Dams from the FAO AQUASTAT regional inventories, matched to the nearest river reach, so a dam on a tributary close to a main stem can be counted against the main stem. The same rivers are drawn on the water map above under Rivers & lakes.

Turkey receives about 450 billion m³ of precipitation a year, but State Hydraulic Works (DSİ) counts only 112 billion m³ as net usable. The country uses about 57 billion m³: 44 billion for irrigation, some 77% of the total, and 13 billion for drinking water and industry.¹⁴ Usable water per person fell from 1,652 m³ in 2000 to 1,544 m³ in 2009 and 1,346 m³ in 2020.¹⁴

Irrigation drives the demand. DSİ calculates that 8.5 million ha could be irrigated with existing water, and by the end of 2019 some 6.65 million ha had been opened to irrigation.¹⁴ Turkey operates 861 dams. The largest reservoirs are Atatürk at 817 km², Keban at 675 km² and Ilısu at 313 km².¹⁴

GAP: targets and delivery

The Southeastern Anatolia Project took its name in 1977, when the Lower Euphrates and Tigris plans were merged.¹⁵ 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.¹⁵ Keban, finished in 1974, predates the project. Karakaya followed in 1987 as GAP’s first dam, then the Atatürk Dam, whose reservoir can hold 48,700 MCM, the Euphrates’ entire annual discharge.¹⁶

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.¹⁵ 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% of the master-plan target. Just 11,331 ha were added in 2024.¹⁵ The largest scheme with nothing yet completed, the Silvan gravity system, covers 128,897 ha.¹⁵

Treated wastewater plays almost no part yet. Reuse stood at 3.2% in 2021, against targets of 5% for 2023 and 15% for 2030.¹⁹

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.

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.

State Hydraulic Works (DSİ) built one of the largest dam fleets in the region. 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 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

Earthquake damage

The February 2023 earthquakes struck the heart of the network. DSİ estimated damage to its facilities at about 19.5 billion lira, or US$1.03 billion.⁷ Irrigation facilities covering 923,976 ha and 39,113 wells were damaged.⁷ Sultansuyu Dam in Malatya was so badly damaged that it must be rebuilt, and Reyhanlı Dam in Hatay can operate again only after reinforcement.⁷ Losses and theft already took 36.8% of water in the 11 affected provinces, against a national average of 35.4%.⁷

Irrigation networks

Canals are giving way to pipes. In DSİ schemes, 35% of systems are conventional canals, 40% canalettes and 25% closed pipes. The piped share is set to reach 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.⁸ A World Bank project covering 50,764 ha had completed 15,280 ha and 694.54 km of network by 2024.⁸

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.⁶ 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

The asset base in numbers

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.

Turkey’s transboundary rivers leave the country relatively clean. The Euphrates averaged about 237 ppm salinity in Turkey in 2002–03, and 248 ppm at Jarablus on the Syrian border. Its salinity at least doubles between that border and Iraq. The UN-ESCWA inventory attributes this partly to Turkish irrigation return flows.¹⁶ 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.¹⁷ Syria and Iraq have alleged that Turkey releases polluted water across the border, which Turkey rejects.²⁰

The Ergene and the Sea of Marmara

The worst pollution lies in the northwest, where about 2,600 industrial plants discharge into the Ergene in Thrace, a basin of more than a million people. Experts rank it as Turkey’s fourth most polluted river.²² 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 1.5.²³ 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.²²

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.¹⁹ At the time 53% of the region’s wastewater received only preliminary treatment. The plan set out to convert all plants to advanced biological treatment within three years and to cut nitrogen loads by 40%.¹⁹ That month a phosphate fertiliser plant in Bandırma was fined TL 96,561 for discharging untreated wastewater.²⁴

The reported indicators

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 means an improved source on the premises, available when needed and free from priority 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.

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.²¹

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.¹⁶ 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.²⁰ Its stated principles are equitable, reasonable and optimal use, no significant harm, and no role for third parties.²¹

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.²⁵ 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.²⁵ Turkey has not acceded to it.²⁶

Protocols and committees

The 1946 treaty with Iraq addressed flow regulation, flow data and prior notification.¹⁷ A 1980 protocol created a Joint Technical Committee, which Syria joined in 1983. It held sixteen meetings and is no longer functional.¹⁶²⁰ 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.²⁰ Filling Atatürk in early 1990 temporarily interrupted the flow.²⁰

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.¹⁷ 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.²⁷ Critics put the number of people resettled at about 50,000.¹⁷

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 2011.¹⁸²⁸ The two have no agreement on allocation, and the dispute over Hatay province is unresolved.¹⁸ On the Çoruh, upstream of Georgia, Turkey inaugurated the 558 MW Yusufeli Dam in November 2022.²⁹ On the Arpaçay (Akhurian) border river with Armenia, a 525 million m³ reservoir irrigates about 104,000 ha in both countries.³⁰

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.³¹ In July 2025 President Erdoğan agreed to raise releases into the Tigris and Euphrates to 420 m³/s.³² On 2 November 2025 the foreign ministers signed a financing mechanism: Turkish companies build Iraqi water projects, paid through Iraqi oil sales.³³ 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.³⁴

The record

Shared river basins

The register also places small areas of Turkey in the Nahr El Kebir, Velaka basins, too little to carry here.

Cooperation and conflict on the record, 1948 to 2008

The International Water Events Database scores every reported interaction between riparian states on the Basins at Risk scale, from formal war over water to voluntary unification. Cooperative and conflictive events add up to less than 100% because neutral events are counted too.

Source: Transboundary Freshwater Dispute Database, International Water Events Database, Oregon State University, as compiled by the Transboundary Waters Atlas. The series ends in 2008; every later dispute and agreement is outside it and is covered in the text above.

The agreements

Source: Master Treaties Database of the Transboundary Freshwater Dispute Database (February 2023 edition), via the Transboundary Waters Atlas. Titles as recorded, with spelling normalised. Colonial-era boundary instruments appear because they fixed water rights on rivers that later became international.

Joint bodies

• Aral Sea Basin Programme (ASBP)Aral · 1994 · Kazakhastan, Kyrgyztan, Tatjikistan, Turkmenistan, Uzbekistan
• Dostluk Commission (DOCO)Harirud · 2007 · Iran, Turkmenistan
• International Fund for Saving the Aral Sea (IFAS)Aral · 1998 · Uzbekistan, Kasakhstan, Kyrgyztan, Tatjikistan, Turkmenistan
• Interstate Commission for Water Coordination in Central Asia (ICWC)Aral · 1992 · Uzbekistan, Kazakhstan, Kyrgyztan, Tajikistan, Turkmenistan
• Joint Boundary Water Commission (JBWC)Coruh · 1973 · Georgia, Turkey
• Joint Technical Committee on Regional Waters (JTCW)Euphrates-Tigris · 1980 · Iraq, Syria, Turkey
• Kura Araks Joint Commission (KAJC)Kura-Araks · year not recorded · Georgia, Turkey

Source: the river basin organisation database of the Transboundary Freshwater Dispute Database (2013). A joint body on paper is not evidence that it meets.

Shared aquifers

• Aghdarband AquiferIran, Turkmenistan · data limited
• Amu Darya (2)Kazakhstan, Turkmenistan, Uzbekistan · data limited
• Birata-UrgenchTurkmenistan, Uzbekistan · data limited
• Janatabad AquiferAfghanistan, Iran, Turkmenistan · data limited
• Sarakhas AquiferIran, Turkmenistan · data limited
• SherabadTurkmenistan, Uzbekistan · data limited

Source: IGRAC and UNESCO, Transboundary Aquifers of the World. Data reliability is IGRAC’s own assessment of the information behind each outline.

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 2022.⁸ DSİ is responsible only for conveyance networks, not for losses on farms.⁸

Plans and targets

The National Water Plan for 2026–2035 was approved by Presidential Decision No. 11063 and published on 14 March 2026.⁹ Prepared by the Ministry of Agriculture and Forestry, it targets network losses of 25% by 2030 and 10% by 2050.¹⁰ Daily use per person is to fall to 120 litres by 2030 and 100 litres by 2050.¹⁰ Irrigation efficiency is to reach 60% by 2030 and 65% by 2050, and industrial water recovery 30% and 50%.¹⁰ A National Drought Management Strategy and Action Plan was published on 31 August 2017, with drought plans for all basins due by 2023.¹

Paying for water

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 has more water than its neighbours, but less than its farms and cities now demand. Usable water per person fell from 1,652 m³ in 2000 to 1,346 m³ in 2020.¹⁴ In 2025 rainfall fell by more than a quarter, and the country set a heat record of 50.5 °C.³ Models point to hotter summers and, under high emissions, much drier autumns.¹

The National Water Plan sets the test for the next decade. City network losses are to fall to 25% and irrigation efficiency to rise to 60% by 2030.¹⁰ Konya’s sinking plain shows the cost of delay.¹² Downstream, Syria and Iraq will judge Turkish policy by what crosses the border. The oil-for-water framework with Iraq now ties Turkish contractors to that question.³⁴