Water in Algeria

Africa's largest country solves water with scale. When drought emptied the coastal dams of the early 2020s, Algeria ordered five 300,000 m³/day desalination plants at once and delivered them by 2025. That lifted national capacity toward 3.7 million m³/day and made the sea the primary source for the coastal cities. Behind the littoral, the Saharan majority of the country runs on the vast fossil aquifer system shared with Tunisia and Libya.

The bet on the sea is being executed at speed. The five 300,000 m³/day plants inaugurated in 2025 were built largely by domestic contractors. The programme is designed to lift desalination's share of drinking water from roughly 18% to 42%, with a further wave planned to 2030.⁵⁵

A quick-reference dashboard for Algeria: headline economy and water indicators⁵⁶⁵⁷, 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 Algeria'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.

Algeria covers about 2.4 million km², most of it Sahara.³³ The coast and mountain massifs cover only 4% of the country and the high plateaux about 9%.³¹ North of the Saharan Atlas lies a semi-arid belt of coastal strip, interior plains and high plateaux. It held more than 90% of the population in 1992.³³ The country is divided into five hydrographic basins, and the Saharan basin alone covers about 2 million km².³¹

From 1,600 mm to almost nothing

Winter rains on the coast and mountains are violent and erosive. They reach 1,600 mm a year on the highest relief and vary sharply from year to year.³¹ The high plateaux get 100–400 mm and the Sahara less than 100 mm.³¹ FAO puts the national average at 89 mm a year.³¹ Potential evapotranspiration runs from 800 mm in the north-east to more than 2,200 mm in the south-east.³¹ In the north, rainfall tracks the North Atlantic Oscillation closely.⁴

Heat, drought and fire

Summers on the high plains regularly exceed 30 °C, and Saharan days can reach or pass 50 °C.² Ouargla recorded 51.3 °C on 5 July 2018.³ Algeria warmed by 0.49 °C a decade between 2000 and 2023, against 0.37 °C globally.² Rainfall fell across most of North Africa between 1971 and 2000, before a return to normal or wetter conditions in Algeria since 2000.¹ Drought still bites. In the early 2000s rainfall deficits reached 50% in the centre and 60% in the east.³⁴ Wildfires burned nearly 310 km² a year in 2010–2019.² Fires in August 2021 killed at least 32 people, including 25 soldiers.⁵

Projections

The IPCC projects that meteorological droughts over Mediterranean North Africa will lengthen from about two months to about four by 2050–2100 under a high-emissions scenario.¹ At 2 °C of global warming and above, mean rainfall declines, most in the north-west.¹ The IEA expects steep rainfall declines in the densely populated north, raising the risk of drought and wildfire. The desert may see more extreme rain and flash floods.² Under high emissions, warming could reach 5.6 °C above pre-industrial levels by 2100.²

Rainfall and temperature in numbers

Averaged over the whole of Algeria, ERA5 reanalysis gives about 70 mm of rain a year and a mean temperature of 23.7 °C for 1991–2020. About 33% of that rain falls in October, January and March, and 3 months average less than 5 mm. Since 1971 the country has warmed by about 0.48 °C a decade. Average rainfall in 1993–2022 was about 15% 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.

Algeria draws on three waters. Erratic northern surface flows sit behind some 80 dams, and the renewable coastal aquifers are over-pumped around Algiers and Oran. The North-Western Sahara Aquifer System's fossil water irrigates the southern oases and supplies Hassi Messaoud's oil economy. Reuse is growing from a low base, but the state's wager is squarely on the sea.

The main rivers

The table ranks the rivers of Algeria 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 Algeria 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.

Algeria’s resources were estimated at 19.1 billion m³ a year in 1992. In the north, 1.5 of 1.8 billion m³ of available groundwater was already exploited.³³ In 2000 withdrawals reached 6.07 billion m³, of which irrigation took 65%, households 22% and industry 13%.³¹ Distribution networks lost about 40% of their water in 2004, against a target of 25%.³⁴

Dams and silt

In 1992, 45 dams supplied an average of 2.2 billion m³ a year.³³ By 2000 there were 48, with an initial capacity of about 5 billion m³ that silt had cut by more than 25%.³¹ Building has continued. Five dams entering service from 2026 will bring the national total to 86, according to the dams agency.³⁷ After heavy rain, dams were close to 60% full in May 2026.³⁸

Irrigation

By 2001 Algeria had equipped 569,418 ha for irrigation, 7% of its cultivated land, with groundwater supplying 69% of it.³¹ The large public schemes fared worst. Of 149,860 ha equipped, only 33,763 ha were irrigated in 2001, as drought struck and water went to drinking supply instead.³¹ Small and medium farms relied on boreholes and wells, and FAO warned that their growth threatened aquifers that were mostly overexploited already.³¹

The Saharan south

Abstraction from the Saharan aquifers rose from about 0.6 billion m³ in 1970 to 3.2 billion m³ in 2018. Average recharge is only about 1 billion m³ a year.³⁶ About 470,000 ha were irrigated in the basin in 2014, 270,000 ha of them on its water, mostly by surface methods.³⁶ The deep waters at In Salah are 19,000–35,000 years old and barely renewed.⁵⁰ A 700 km transfer carries this fossil water to Tamanrasset.⁴² Around El Oued, water tables rose from the 1980s and drowned palms. Since the 2010s irrigation has pulled them below 9 m, drying the traditional Ghout gardens.⁵¹⁵²

Turning to the sea

Desalination began in industry. In 1980 a 57,600 m³/day plant at Mostaganem, built for a paper factory, was the world’s largest reverse-osmosis plant.³⁴ An emergency in 2002–03 brought 21 small plants to coastal towns. In 2004 the ministry planned 28 large plants along the 1,300 km coast.³⁴ Cap-Blanc near Oran opened on 20 February 2025, the first of five 300,000 m³/day plants.⁴⁰ The state desalination company says the five lifted capacity from 2.2 to 3.7 million m³/day, from about 18% to 42% of drinking-water needs.³⁵ Construction of a 140,000 m³/day plant at Skikda began in July 2026.³⁹

Withdrawals over time

FAO’s AQUASTAT estimates put Algeria’s freshwater withdrawals at 2.0 billion m³ in 1970 and 10.3 billion m³ in 2022. Agriculture’s share of the total moved from 74% in 1984 to 67% 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.

Dams hold most of Algeria’s surface storage. The dams agency managed 80 dams in 2024, and five more are due to enter service from 2026, bringing the national total to 86.⁶³⁷ Beni Haroun in Mila is the largest.¹⁰ Silt is a constant drain: about 4,000 tonnes of soil per km² reach the dams or the sea each year.¹¹

Transfers

The dams agency runs seven transfer systems, among them Beni Haroun, Taksebt, Koudiet Acerdoune and the Mostaganem–Arzew–Oran corridor.⁶ Beni Haroun is the largest. It was designed for 504 million m³ a year, later revised to 475 million, to supply six eastern wilayas and irrigate 41,223 ha. Its first phase opened in September 2007.⁷ Taksebt secures supply to Algiers across three wilayas.⁸ In August 2026 the ministry agreed in principle to take Beni Haroun water to Biskra and El Kantara.⁹ In the far south, a 700 km transfer carries fossil water to Tamanrasset.⁴²

Desalination

The coast now carries a fleet of large seawater plants. In the west, Honaine, Mostaganem and Ténès each produce 200,000 m³/day.¹²¹³¹⁴ In the east, Cap Djinet II and El Tarf each produce 300,000 m³/day.¹⁵¹⁶ Fouka 2 reached its full 300,000 m³/day in July 2025.¹⁸ Three more 300,000 m³/day plants, at Chlef, Mostaganem and Tlemcen, are in the state desalination company’s new programme.¹⁷ Estimates of desalination’s share differ. It is 16% of the national utility’s production on that utility’s own figures, but 42% of drinking water on the desalination company’s.¹⁹³⁵

Networks and sanitation

The national water utility ADE delivers 5.5 million m³ a day to more than 28.5 million people through 83,407 km of pipes.¹⁹ It manages 1,019 of Algeria’s 1,541 communes.²⁰ The sanitation office ONA runs 190 treatment plants with a nominal capacity of 1.9 million m³ a day, and 72,228 km of sewers.²¹ In Algiers and Tipaza, the joint company SEAAL supplies about 5 million people.²² Flooding takes 70% of the annual disaster-response budget, about US$255 million a year.²

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.

Around 2005, 44% of Algeria’s inventoried waters were rated good, 44% satisfactory and 12% poor.³¹ Long stretches of the Tafna, Macta, Chéliff, Soummam and Seybouse were polluted. Pollution in the Chéliff threatened drinking water for the valley’s two million people.³¹ On the coast, over-pumping causes irreversible saline intrusion around Oran, Algiers and Jijel. Nitrate pollution has been recorded in the Mitidja aquifer.³¹ In Oued Souf, shallow groundwater reaches a conductivity of 18,680 µS/cm and is unfit to drink.⁵³

Wastewater output was put at 820 million m³ a year in 2002.³¹ In 1992 the World Bank judged reuse for coastal irrigation not viable because of pumping costs.³³ By November 2025 Algeria had 230 treatment plants, the water minister said.⁴¹

Cholera, 2018

Before 2018, Algeria’s last confirmed cholera case dated from 1996.⁴³ In August 2018 an outbreak spread across seven wilayas, with more than half of early confirmed cases in Blida.⁴³ Of 21 water sources tested, 10 were unfit, and one tested positive and was condemned.⁴³ By 27 September, 291 suspected cases had been reported, 97 of them confirmed.⁴⁴ Investigators isolated the bacterium from wastewater, two public drinking-water sources and stored water.⁴⁴ Between 2000 and 2023, typhoid and dysentery fell by nearly 98%.⁵⁴

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.

Algeria shares the Medjerda with Tunisia and the Tafna, Guir, Dra and Daoura with Morocco.³³ It is not a member of the Lake Chad Basin Commission or the Niger Basin Authority.³¹ Surface-water cooperation is thin. Formal frameworks with Tunisia for the Medjerda were still to be defined in 2025, IUCN noted.⁴⁵ Morocco’s Kaddoussa dam on the upper Guir has been in service since 2021.⁴⁶

The Saharan aquifers

The North-Western Sahara Aquifer System covers more than 1 million km², and Algeria holds 68% of it.³² The Sahara and Sahel Observatory launched a joint study in 1999. Its first phase, to 2002, built a shared hydraulic model and began a consultation mechanism.³⁶ On 24 April 2024 Algeria, Libya and Tunisia signed an agreement in Algiers on consultation over the shared groundwater. Tunisia ratified it in January 2025.⁴⁷⁴⁸ On 29 July 2026 Algeria and Libya agreed a roadmap for cooperation on irrigation, desalination and water resources.⁴⁹

The record

Shared river basins

The register also places small areas of Algeria in the Oued Bon Naima basin, 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

• Niger Basin Authority (NBAX)Niger · 1980 · Algeria, Benin, Burkina Faso, Cameroon, Chad, Guinea, Ivory Coast, Mali, Niger, Nigeria, Sierra Leone

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

• Angad-Maghnia Unconfined Aquifer; Jbel-Hamra Confined AquiferMorocco · data moderate
• Aïn Béni MatharMorocco · data moderate
• Chott Tigri-LahouitaMorocco · data limited
• Errachidia Aquifer SystemMorocco · data good
• Figuig OasisMorocco · data moderate
• Kasserine Aquifer SystemTunisia · data moderate
• Lake Chad sedimentary basin / Bassin sédimentaire du Lac TchadCameroon, Central African Republic, Chad, Niger, Nigeria · data moderate
• North-Western Sahara Aquifer System / Système Aquifère du Sahara SeptentrionalLibya, Tunisia · data good
• Système Aquifère de Mourzouk - Djado / Murzuk-Djado Aquifer SystemChad, Libya, Niger · data limited
• Système Aquifère des Iullemmeden / Iullemmeden Aquifer SystemBenin, Mali, Niger, Nigeria · data moderate
• Taoudeni-Tanezrouft Aquifer System / Système Aquifère de Taoudéni-TanezrouftBurkina Faso, Mali, Mauritania · data moderate
• Tindouf Aquifer SystemMauritania, Morocco · data moderate

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

Algeria’s water administration grew from a state secretariat for hydraulics in 1971 into a full Ministry of Water Resources in 2000.²³²⁴ By 2023 the ministry was known as the Ministry of Hydraulics.²⁵ Delivery sits with public companies. ADE, created in 2001, supplies drinking water, and ONA, also created in 2001, runs sanitation.²⁰²¹ The dams agency ANBT and the irrigation office ONID took their current form in 2005.²⁶²⁷ A national agency for integrated water management, AGIRE, followed in 2011, with the basin agencies as its branches.²⁸

Law and tariffs

Law 05-12 of 4 August 2005 is the legal base. It creates a national water plan and a master plan and basin agency for each hydrographic unit.²⁹ It allows an autonomous regulator for water services. It also lets the state delegate their management to public or private operators, through competitive tender.²⁹ Decree 05-13 of January 2005 sets progressive tariffs across five territorial zones.³⁰ The base rate in Algiers, Oran and Constantine is DA 6.30 per m³, and households pay up to 6.5 times that in the top block.³⁰

SEAAL, created in 2006 and owned 70% by ADE and 30% by ONA, runs water and sanitation for Algiers and Tipaza.²² In 2021 Algerian managers took over its management.²²

Algeria has bet on the sea, and the bet is being delivered. The next test is running the fleet. Plants at Chlef, Mostaganem and Tlemcen will add 900,000 m³ a day, and each depends on energy and maintenance budgets.¹⁸ Dams will not close the gap alone: silt keeps cutting their capacity, and projections point to less rain in the populated north.¹¹²

Three questions will shape the decade. Can networks be fixed as fast as plants are built? Will tariffs set in 2005 ever move toward cost?³⁰ And can the Saharan aquifers shared with Tunisia and Libya be pumped at a pace the 2024 consultation agreement can manage?⁴⁷ The model works as long as the treasury does.