Water in Bahrain

The island named itself for water: "the two seas", after the freshwater springs that once bubbled through the seabed, and then pumped those springs silent. Today Bahrain is a compact desalination economy. Over 90% of drinking water comes from the sea,⁹ groundwater is held in reserve, and reuse is expanding from the Tubli works. Small scale makes it nimble; density makes every drop urban.

Bahrain is the cautionary tale of what happens after the springs stop. Most of the springs that named the island had stopped flowing by the 1980s as the aquifer was overdrawn.⁶ Since 2016, authorities say, supply has relied fully on desalination.¹¹ The groundwater that remains serves landscaping and a shrinking agricultural fringe.

A quick-reference dashboard for Bahrain: headline economy and water indicators²¹²², 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 Bahrain'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.

Bahrain is an archipelago of low islands. FAO counts 40 islands with about 710 km², while the third national communication gives about 780 km².⁶¹ The difference is largely reclamation: 111 km² has been added since 1980, about 15% of today’s land.¹ The coastline runs 946 km.¹ Bahrain Island is nearly 85% of the land area.⁶ The highest point, Jabal Dukhan, is 135 to 137 m and holds the country’s only oil field.¹⁶ Desert dominates, apart from a narrow fertile strip along the northern and north-western coasts.¹ Most people and infrastructure sit on land less than 5 m above sea level.¹ Dredging for reclamation has done lasting damage to coastal habitats, and less than 10% of the former dense Acropora coral cover remains.¹

Rainfall and heat

The rainy season runs from November to April, averaging 83 mm a year.⁶ 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.¹ Rain is negligible from April to the end of October.¹ Potential evaporation reaches 2,099 mm a year.⁶ Temperatures average 17 °C in winter and 35 °C in summer.⁶ The monthly mean peaks at 34.6 °C in August, and the annual mean is 26.7 °C.¹ Humidity is highest from December to February.¹ Across South West Asia, the IPCC finds that warming has amplified droughts since the 1980s.³

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.² 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.¹ For sea level, the communication built an upper bound of about 5 m by 2100 and tested scenarios from 0.5 m upward.¹ At 0.5 m, about 27 km², nearly half of Bahrain’s wetlands, would be inundated.¹ At 5 m, the airport would flood entirely, and only 72 of 470 km² of sensitive land would stay dry.¹ Rising seas also threaten the freshwater lenses and the intakes and outfalls of desalination plants.¹

Rainfall and temperature in numbers

Averaged over the whole of Bahrain, ERA5 reanalysis gives about 68 mm of rain a year and a mean temperature of 26.2 °C for 1991–2020. About 62% of that rain falls in November, December and January, and 7 months average less than 5 mm. Since 1971 the country has warmed by about 0.28 °C a decade. Average rainfall in 1993–2022 was about 10% higher 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.

Bahrain has no rivers, perennial streams, lakes or dams, and surface runoff is only about 4 million m³ a year.⁶ Renewable groundwater comes to 3 m³ per person.¹ Water arrives by lateral underflow in the Dammam aquifer, which is recharged in central Saudi Arabia at about 300 m above sea level.⁶ Inflow before 1965 was about 112 million m³ a year.⁶ Decades of over-pumping salinised the aquifer, and most springs had stopped flowing by the 1980s.⁶

Groundwater now accounts for only about 9% of water production, and desalination meets about 95% of municipal demand.¹ On GCC-Stat figures for 2023, 59% of the national supply of 0.5 billion m³ was desalinated and 32% groundwater.⁴ Treated effluent from Tubli irrigates the island’s green space.

Bahrain once lived on springs. Before 1925 free-flowing springs and hand-dug wells discharged an estimated 93 million m³ a year.⁶ Borehole pumping began after oil and gas exploration started in 1946, and by the 1980s most springs had stopped flowing as seawater intruded.⁶ Withdrawals from the Dammam aquifer almost doubled between 1952 and 1966.⁷ 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 m³.⁷

Total withdrawal reached 357.4 million m³ in 2003, equal to 220% of renewable resources. Irrigation and livestock took 45%, down from 56% in 1991.⁶ Groundwater supplied 238.7 million m³, desalination 102.4 million m³ and treated effluent 16.3 million m³.⁶ Salty irrigation water has shrunk the cultivated area, about 6,000 ha in 2005.⁶ Population grew from 0.55 million in 2000 to almost 1.5 million in 2018.⁸

The switch to the sea

Bahrain’s first seawater desalination plant opened in 1975 at Sitra. The Ras Abu-Jarjur plant, desalinating brackish groundwater at 45,500 m³ a day, followed in 1984.⁶ Authorities say Bahrain became fully reliant on desalinated water in 2016, with all groundwater reserved for contingencies.¹¹ Desalination meets over 90% of drinking water and 67.5% of total demand.⁹ Unusually for the Gulf, more desalinated water goes to industry than to homes.⁸ New capacity is in procurement. Bids for the Hidd water project were received in April 2026, and ACWA Power and TAQA are the final bidders for the Sitra power and water plant.¹²¹³ Reuse of treated wastewater for farms and landscaping began in 1985.⁶

Withdrawals over time

FAO’s AQUASTAT estimates put Bahrain’s freshwater withdrawals at 195 million m³ in 1990 and 155 million m³ in 2022. Agriculture’s share of the total moved from 53% in 1994 to 33% 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.

Desalination carries the country. The fleet’s combined capacity is about 846,000 m³ a day.¹ Sitra, from 1975, uses multi-stage flash at 113,600 m³ a day, and Al-Hidd, from 1999, is the largest at 409,100 m³ a day.¹ Ras Abu Jarjur, from 1984, runs reverse osmosis on groundwater, and the Al-Dur reverse-osmosis plant of 2012 adds 218,200 m³ a day.¹

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.¹ Tubli, online since 1982, is the largest. It gives tertiary treatment, is designed for 200,000 m³ a day and serves 700,000 people.¹ North Sitra, from 2008, is designed for 16,500 m³ a day.¹ The Muharraq plant, a 100,000 m³ a day build-own-operate concession with a 15.9 km deep gravity sewer, reached financial close in September 2011.⁵ It was owned 45% by Samsung, 35% by Invest AD and 20% by United Utilities.⁵

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.¹ The Electricity and Water Authority runs a leakage detection and control group, and the national communication’s adaptation scenario phases in leak reduction to 2035.¹

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.

After four decades of over-pumping, most of Bahrain’s original groundwater reservoir has been lost to salinisation.¹⁴ Overuse drew saline water into the Dammam aquifer from the underlying Umm er Radhuma, and sabkha water intruded in the south-west.⁶ Most water abstracted in the region is below 5 g/L, but coastal wells with seawater intrusion reach 80–100 g/L.⁷ Water levels in the Dammam have fallen by about 4 m a year, and the aquifer is now mostly dewatered.⁷

Wastewater treatment is centralised at Tubli. In 2005 it produced about 160,000 m³ a day of secondary effluent, of which about 60,700 m³ received tertiary treatment.⁶ Water supply and sanitation coverage were both 100%.⁶

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.

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 m³.⁷ FAO put the inflow before 1965 at about 112 million m³ a year.⁶ Bahrain holds about 560 km² of the system. No water agreement covers it, though Bahrain has stated an interest in cooperating.⁷

The 2026 war

On 8 March 2026 Bahrain’s interior ministry said an Iranian drone had damaged a desalination plant.¹⁵ It was the first such attack reported by a Gulf state in the war.¹⁶ The ministry said operations were not disrupted.¹⁷ Iran denied attacking desalination plants in Bahrain and Kuwait and blamed Israel.¹⁰ In April drone shrapnel damaged houses in Sitra, the island that hosts Bahrain’s main energy facilities.¹⁸ The government reports reserves for four days if the desalination plants shut down.¹⁰ GCC leaders made water interconnection a priority in April 2026.¹⁹

The record

Shared aquifers

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

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

The Electricity and Water Authority sets tariffs and runs the network.¹ From 1 March 2016, block tariffs for commercial, industrial, tourism and other non-household users were raised gradually under a new schedule.¹ The Ministry of Works runs public wastewater treatment, and receives treated effluent from the Muharraq concession at the plant boundary.¹⁵ The Supreme Council for Environment coordinated the third national communication.¹ 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.¹ 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.¹

Bahrain’s water is almost entirely manufactured, and its margin is thin. Groundwater is about 9% of production, the aquifer is largely salinised, and the islands are low and crowded.¹⁶ Rising seas threaten the freshwater lenses that remain, along with desalination intakes and outfalls.¹

The agenda is efficiency within constraints: the next plant phases, Tubli’s treatment works, leak reduction toward the 2035 target, and cooperation with Saudi Arabia on the shared aquifer.¹ It is a small system, well run, and wholly dependent on the sea.