Water in Bahrain

Bahrain is a low-lying archipelago with no rivers, lakes or dams, and receives an average of 83 mm of rain a year.¹ Its groundwater flows in from Saudi Arabia through the Dammam aquiferDammam aquifer Part of the Umm er Radhuma–Dammam aquifer system, mainly limestone and dolomite, which Bahrain shares with Qatar and Saudi Arabia. The Dammam is the main source of irrigation water in Bahrain. Source: Inventory of Shared Water Resources in Western Asia, chapter 15: Umm er Radhuma-Dammam Aquifer System (Centre), UN-ESCWA and BGR (2013), which decades of over-pumping have salinised.¹ Municipal supply now comes from seawater desalination, while treated wastewater goes to farms and landscaping.^2 3 The margin is thin: the government reports reserves for four days if the desalination plants shut down.⁴

Bahrain once lived on springs. Its name, “the two seas” in Arabic, is often linked to freshwater springs beneath the island,⁵ and in a Sumerian myth the god EnkiEnki The Mesopotamian god of water, later known as Ea. He was lord of the Apsu, the fresh waters beneath the earth, and was first worshipped in the city of Eridu. Source: Ea, Encyclopædia Britannica made fresh water flow for DilmunDilmun The Sumerian name of an ancient kingdom centred on Bahrain Island, which flourished around 2000 BCE. It was a trading point for goods between Sumer and the Indus Valley. Source: Dilmun, Encyclopædia Britannica, whose capital stood at what is now Qal’at al-BahrainQal’at al-Bahrain An archaeological mound built up by successive layers of occupation from about 2300 BC to the 16th century AD. It was the capital of Dilmun, and takes its name from the Portuguese fort (qal’a) on its top. Source: Qal’at al-Bahrain: Ancient Harbour and Capital of Dilmun, UNESCO World Heritage Centre.^6 7 Some springs rose from the sea floor. Off Muharraq, archaeologists have found a cistern built around one of them, tentatively identified as a water station for an early Islamic pearling fleet.^8 9 Borehole pumping began after oil and gas exploration started in 1946, and the first seawater desalination plant opened at Sitra in the mid-1970s.^1 3 By the 1980s, most springs had stopped flowing as seawater intruded.¹

Desalination has not ended groundwater pumping. In 2021, groundwater still made up 36% of all water supplied.¹⁰ Wastewater treatment is also expanding: the capacity of the Tubli sewage treatment plant is being doubled to 400,000 m³ a day.¹¹ Reliance on the sea carries its own risk. In March 2026, the interior ministry said a drone had damaged a desalination plant, though operations were not disrupted.^12 13

One interactive map of Bahrain'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 each sub-basin by its 0–5 risk score. Infrastructure shows treatment plants and desalination plants; Bahrain has no rivers or dams. Hover any sub-basin or marker for detail; sources are cited under each view.

Bahrain is an archipelago of low islands. FAO counts 40 islands with about 710 km², while the third national communication gives about 780 km².^1 3 The difference is largely reclamation: 111 km² has been added since 1980, about 15% of today’s land.³ The coastline runs 946 km.³ Bahrain Island is nearly 85% of the land area.¹ The highest point, Jabal Dukhan, is 135 to 137 m and holds the country’s only oil field.^3 1 Desert dominates, apart from a narrow fertile strip along the northern and north-western coasts.³ Most of the population and infrastructure are on six major islands, whose coastal areas, less than 5 m above current sea levels, have very high population densities.³ Dredging for reclamation has done lasting damage to coastal habitats. With large-scale coastal development and the bleaching episodes of the 1990s, less than 10% of the former dense Acropora coral cover remains.³

Rainfall and heat

The rainy season runs from November to April, averaging 83 mm a year.¹ Monthly normals for 1960–2017 put January at 19.5 mm and February at 19.0 mm, with no rain at all from June to September.³ Rain is negligible from April to the end of October.³ Potential evaporation reaches 2,099 mm a year.¹ Temperatures average 17 °C in winter and 35 °C in summer.¹ The monthly mean peaks at 34.6 °C in August, and the annual mean is 26.7 °C.³ Humidity is highest from December to February.³ Across South West Asia, the IPCC finds that warming has amplified droughts since the 1980s.¹⁹

In the World Bank Climate Change Knowledge Portal’s ERA5 reanalysis, averaged over the whole of Bahrain, about 68 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 83 mm a year, FAO’s average). About 62% of the rain falls in November, December and January, and 7 months average less than 5 mm. Average rainfall in 1993–2022 was about 10% higher than in 1951–1980, and single years swing widely around that.

The same reanalysis gives a mean temperature of 26.2 °C for 1991–2020 and a warming of about 0.28 °C a decade over 1971–2022. Station records and national reports use other sources and periods, so their warming rates can differ.

Projections

In the World Bank’s CMIP6 ensemble, the annual mean temperature rises from 26.3 °C in 1995–2014 to about 31.3 °C by 2080–2099 under high emissions.²⁰ Bahrain’s own water model assumed warming of 0.22 °C by 2035 under a middle scenario and 0.96 °C under high emissions, with each degree adding 1.38 m³ to water use per person.³ For sea level, the communication built an upper bound of about 5 m by 2100 and tested scenarios from 0.5 m upward.³ At 0.5 m, about 27 km², nearly half of Bahrain’s wetlands, would be inundated.³ At 5 m, the airport would flood entirely, and only 72 of 470 km² of sensitive land would stay dry.³ Rising seas also threaten the freshwater lenses and the intakes and outfalls of desalination plants.³

Projected change for Bahrain

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.

Bahrain has no rivers, perennial streams, lakes or dams, and surface runoff is only about 4 million m³ a year.¹ Renewable groundwater comes to 3 m³ per person.³ Water arrives by lateral underflow in the Dammam aquifer, which is recharged in central Saudi Arabia at about 300 m above sea level.¹ Decades of over-pumping salinised the aquifer.¹

The national communication of 2020 put groundwater at around 9% of water production, citing a 2018 study, and seawater desalination at about 95% of municipal demand.³ On GCC Statistical Centre figures, with the year not given, 59% of the national supply of 0.5 billion m³ is desalinated, 32% is groundwater and 11% is rainwater.²¹ Treated effluent from Tubli is used for farm irrigation and landscaping.³

Supply by source

Bahrain once lived on springs. Before 1925 free-flowing springs and hand-dug wells discharged an estimated 93 million m³ a year.¹ Borehole pumping began after oil and gas exploration started in 1946, and by the 1980s most springs had stopped flowing as seawater intruded.¹ Withdrawals from the Dammam aquifer almost doubled between 1952 and 1966.²² By 2010 Bahrain drew 97 million m³ a year from the Dammam, plus 54.3 million m³ from the Umm er Radhuma in 2006, against a safe yield of 90 million m³.²²

Total withdrawal reached 357.4 million m³ in 2003. Freshwater withdrawal alone, comprising primary groundwater and reused treated wastewater, represented 220% of renewable water resources. Irrigation and livestock took 45%, down from 56% in 1991.¹ Groundwater supplied 238.7 million m³, desalination 102.4 million m³ and treated effluent 16.3 million m³.¹ Salty irrigation water has shrunk the cultivated area, about 6,000 ha in 2005.¹ Population grew from 0.55 million in 2000 to almost 1.5 million in 2018.²³

Use by sector

Withdrawals over time

FAO AQUASTAT reports total water withdrawal of 430 million m³ in 2023, including 180 million m³ of groundwater withdrawal.²⁴ The World Bank freshwater-withdrawal series reports 195 million m³ in 1990 and 155 million m³ in 2016, carrying the latter through 2022. Agriculture’s share of the total moved from 53% in 1994 to 33% in the latest estimate (2016).

Agriculture, forestry and fishing used 147.3 million m³ of freshwater in 2021, of which farms abstracted 95.7 million m³ themselves and the water supply industry supplied 5.7 million, according to the ministry’s accounts.¹⁰ The Third National Communication puts farm water demand at about 125 million m³ in 2015, with treated wastewater meeting about 23% of the sector’s requirement, and farmland at about 3,700 ha as groundwater turned saline.³

Land and methods

The ministry’s data show 2,000 ha cultivated with crops in 2025, against 3,730 ha in 2015.²⁶ FAO’s equipped area is also 3,730 ha, last reported for 2016.²⁷ The communication says flood irrigation covers 65% of irrigated land, at an efficiency of 25 to 40%, drip 32% and sprinklers 3%.³ It adds that 84% of holdings are 5 ha or smaller, tenancies are short and farms pay no water tariff, which discourages investment in efficient irrigation.³

Rules

Government policy is to replace groundwater with treated wastewater delivered free to farms.³ Legislative Decree 12 of 1980 bars digging new wells or altering old ones without authorisation.²⁸ In May 2023 the minister told the Shura Council that work was continuing to connect treated water to all licensed farms and that agricultural legislation was under review.²⁹

Treated wastewater

An average of 154,000 m³ of treated wastewater a day goes to 547 farms covering 3,100 ha, about 92% of agricultural land, but the communication gives no reference year.³ Only the Tubli plant treats part of its flow to tertiary level (29 to 42%); at the privately run Muharraq plant, about 1% of 73,700 m³ a day was reused in 2017.³ Other agricultural water projects are on the Agriculture & Food hub.

Desalination carries the country. Bahrain’s first seawater desalination plant opened in 1975 at Sitra, according to the national communication; FAO dates the first multi-stage flash plant to 1976.^3 1 In 2018 the fleet’s combined capacity was about 846,000 m³ a day.³ Sitra, from 1975, used multi-stage flash at 113,600 m³ a day, and Al-Hidd, from 1999, used multi-stage flash and multi-effect distillation at 409,100 m³ a day.³ Ras Abu Jarjur, from 1984, used reverse osmosis on groundwater, and the Al-Dur reverse-osmosis plant of 2012 added 218,200 m³ a day.³ FAO records Ras Abu-Jarjur desalinating brackish groundwater at 45,500 m³ a day.¹ Al Dur 2 entered commercial operation in the second quarter of 2022 and adds 227,300 m³ a day of reverse-osmosis capacity.^30 31

Authorities say Bahrain became fully reliant on desalinated water for its municipal supply in 2016, with all groundwater reserved for contingency plans.² On CSIS figures, desalination supplies 67.5% of total water demand.¹⁴ New capacity is in procurement. Bids for the Hidd water project were received in March 2026,³² and in July Acwa became the only remaining bidder.³³ ACWA Power and TAQA are the final bidders for the Sitra power and water plant.³⁴

Tracked projects

Open the project database for Bahrain

Wastewater

The Ministry of Works operates 11 treatment plants with a combined capacity of about 352,770 m³ a day, and basic sanitation reaches about 92% of people.³ FAO put water supply and sanitation coverage in urban areas at 100%.¹ Tubli, online since 1982, is the largest. It gives tertiary treatment, was designed for 200,000 m³ a day and serves 700,000 people;³ a phase four expansion aims to increase its capacity to 400,000 m³ a day.¹¹ In 2005 Tubli produced about 160,000 m³ a day of secondary effluent, of which about 60,700 m³ received tertiary treatment.¹ Reuse of treated wastewater for farms and landscaping began in 1985.¹ North Sitra, from 2008, is designed for 16,500 m³ a day.³ The Muharraq plant, a 100,000 m³ a day 29-year BOOT concession with a 16.5 km deep gravity sewer, reached financial close in September 2011.^35 36 It began operating in 2014.³⁷ At close it was owned 45% by Samsung, 35% by Invest AD and 20% by United Utilities;³⁶ Almar Water Solutions acquired a 35% stake in 2019.³⁵

Networks

Gross municipal use is about 500 litres per person a day, including losses from leaks and illegal connections. Net use is 325 to 360 litres.³ The Electricity and Water Authority runs a leakage detection and control group, and the national communication’s adaptation scenario phases in leak reduction to 2035.³

The 2026 war

On 8 March 2026 Bahrain’s interior ministry said an Iranian drone had damaged a desalination plant.¹² It was the first such attack reported by a Gulf state in the war.³⁸ The ministry said operations were not disrupted.¹³ The same day Stars and Stripes reported Iran’s foreign minister, Abbas Araghchi, calling the strike retaliation for a US attack on an Iranian desalination plant.³⁹ By 28 April, according to the Arab Center Washington DC, Iran had denied attacking desalination plants in Bahrain and Kuwait and blamed Israel.⁴ In April drone shrapnel damaged houses in Sitra, the island that hosts Bahrain’s main energy facilities.⁴⁰ The government reports reserves for four days if the desalination plants shut down.⁴

After 30 to 40 years of unsustainable use, more than half of Bahrain’s original groundwater reservoir had been completely degraded by seawater intrusion and saline water up-flow.^1 22 Overuse salinised the Dammam aquifer with water from adjacent saline bodies, particularly the underlying Umm er Radhuma, while sabkha water intruded in the south-west.¹ Most groundwater abstracted across the region had salinity below 5 g/L, but wells in certain coastal areas reached 80–100 g/L.²²

The reported indicators

On the latest values each country reports for SDG indicator 6.3.1, Bahrain’s 94% (2024) ranks 5th of the 17 countries covered here that report it; years differ by country. The regional comparison is in the wastewater and reuse dashboard.

Bahrain’s groundwater comes from Saudi Arabia. The central Umm er Radhuma–Dammam system is its only groundwater source. Lateral inflow from eastern Saudi Arabia is estimated at 83–90 million m³ a year, while direct recharge is only 0.5 million m³.²² FAO put the inflow before 1965 at about 112 million m³ a year.¹ ESCWA reports Dammam water levels falling by 4 m a year and the aquifer mostly dewatered in Bahrain and Qatar;²² FAO reports a fall of about 4 m between 1965 and 1992.¹ Bahrain holds about 560 km² of the system. No water agreement covers it, though Bahrain has stated an interest in cooperating.²² GCC leaders made water interconnection a priority in April 2026.⁴¹

The record

Shared aquifers

• Umm er Radhuma-Dammam Aquifer System (Centre): GulfQatar, Saudi Arabia, UAE · data good

The Electricity and Water Authority sets tariffs and runs the network.³ From 1 March 2016, block tariffs for commercial, industrial, tourism and other non-household users were raised gradually under a new schedule.³ The Ministry of Works runs public wastewater treatment, and receives treated effluent from the Muharraq concession at the plant boundary.^3 36 The Supreme Council for Environment coordinated the third national communication.³ That report calls for institutional reform building on the National Water Resources Council, reactivated in 2016, and for a groundwater cooperation mechanism with Saudi Arabia.³ Building codes from 2009 require the ground floor of a new building to sit 1.5 m above the pavement, an early adaptation to rising seas.³

Bahrain’s water is almost entirely manufactured, and its margin is thin. Its groundwater has been degraded by seawater intrusion and saline water up-flow (see Water quality), and most people and infrastructure sit on low coasts (see Geography & climate). Sea-level rise could push seawater into the fresh groundwater lenses and affect desalination-plant intakes and outfalls.³

The agenda is efficiency within constraints: the next plant phases, the Tubli expansion, leak reduction (modelled to 2035 in the national communication), and cooperation with Saudi Arabia on the shared aquifer.³ It is a small system that depends almost entirely on the sea.