Water supply and sanitation in Iran is overseen by the Ministry of Energy, which sets policy and supervises the provision of services. The renewable water per capita in 2025 for each Iranian has decreased to less than 500 cubic meters per year, whereas this figure was previously 1,500 cubic meters.
Access The sector is characterized by a wide discrepancy in coverage of water and sewerage services, as well as between urban and rural areas. The Joint Monitoring Programme for Water Supply and Sanitation of the WHO and UNICEF, which monitors access figures based on national surveys and censuses, estimated access in Iran from the results of the censuses of 1996, 2006, and 2011 as well as a 1995 Multiple Indicator Cluster Survey. According its estimates, in 2011 access to an improved water supply was 98% in urban areas where more than two thirds of Iranians live. It was 90% in rural areas (87% house connections). Access to sewerage in urban areas was estimated at 19% in the late 1990s. Access to improved sanitation was estimated at close to 100%.
Water resources
Climate
Rainfall in Iran is highly seasonal, with a rainy season between October and March, leaving the land parched for the remainder of the year. Immense seasonal variations in flow characterize Iran's rivers. For example, the Karun River in Khuzestan carries water during periods of maximum flow that is ten times the amount borne in dry periods. In numerous localities, there may be no precipitation until sudden storms, accompanied by heavy rains, dump almost the entire year's rainfall in a few days. Water shortages are compounded by the unequal distribution of water. Near the Caspian Sea, rainfall averages about 1,280 mm per year, but in the Central Plateau and in the lowlands to the south it seldom exceeds 100 mm.Helen Chapin Metz, ed., Iran: A Country Study. Washington: GPO for the Library of Congress, 1987, Chapter "Water".
+ Cumulative Precipitation according to Water Basins (millimeters) Region 2012/13 1970–2014 (average) Caspian Sea 405.2 423.3 Persian Gulf 343.6 358.6 Lake Urmia 278.9 326.7 Central basin 139.0 162.2 Hamun basin 78.5 110.5 Sarakhs basin 244.5 203.9 Iran 203.9 238.6
Water balance Internal renewable water resources are estimated at 128.5 billion cubic meters (BCM)/year (average for 1977–2001). Surface runoff represents a total of 97.3 BCM/year, of which 5.4 BCM/year comes from drainage of the aquifers and thus needs to be subtracted from the total. Groundwater recharge is estimated at 49.3 BCM/year, of which 12.7 BCM/year is obtained from infiltration in the river bed and also needs to be subtracted. Iran receives 6.7 BCM/year of surface water from Pakistan and some water from Afghanistan through the Helmand River. The flow of the Arax river, at the border with Azerbaijan, is estimated at 4.6 BCM/year. The surface runoff to the sea and to other countries is estimated at 55.9 BCM/year. Per capita water availability in the pre-Islamic Revolution era was about 4,500 cubic meters. But, in 2009 this figure was less than 2,000 cubic meters. The total water withdrawal was estimated at 70 BCM in 1993, rising to 93 BCM in 2004, of which 92% was used for agricultural purposes, 6% for domestic use and 2% for industrial use. Although this is equal to 51% of the actual available renewable water resources, annual abstraction from aquifers (57 BCM in 1993, 53 BCM in 2004) is already more than the estimated safe yield (46 BCM). Of the 4.3 BCM/year in 1993 (6.2 in 2004) used for domestic purposes, 61% is supplied from surface water and 39% from groundwater.Seyed Ali Mamoudian, Secretary of the IWA National Committee for Iran: "Iran. Water and wastewater management across the country", IWA Yearbook 2008, p. 28 As of 2014, Iran is using 70% of its total renewable freshwater, far above the upper limit of 40% recommended according to international norms.Bijan Rouhani & Fatema Soudavar Farmanfarmaian:Iran's Imperiled Environment , Payvand News, January 2014 A large part of the water used in agriculture is evaporated instead of properly used because of inefficient consumption patterns. 16 BCM of water was used for power generation in 1999.
Tehran with its population of about 9 million is supplied by surface water from the Lar dam on the Lar River in the Northeast of the city, the Latyan dam on the Jajrood River in the North, the Karaj River in the Northwest, as well as by groundwater in the vicinity of the city. The average Tehran resident uses 325 liters of water (86 gallons) per day. Tap water consumption in the country is 70% over and above the global average.Kayhan:Changing Old Habits, quoting the leader of the Islamic Revolution Ayatollah Seyed Ali Khamenei in his 2009 Norouz message
In March 2016 President Hassan Rouhani said at a conference that the "water consumption pattern" in Iran had to be changed, without making any specific recommendations on how this could best be achieved.
Seawater desalination The Iranian government envisages massive investments in seawater desalination and in pipelines to bring water from the Southern shores to the interior of the country. In a first stage, desalination plants are to be built to supply coastal cities, while in a second stage cities on the central plateau are to be served as well. The plants and pipelines are expected to be financed by the private sector under Build-Own-Operate (BOO) Contracts where the government pays annual fees for the water produced. Such contracts for desalination plants already exist on a small scale with Iranian companies and are expected to be extended to larger contracts with international companies. The power for the desalination plants is expected to be provide at least partly by "small" nuclear power plants. Iranian Energy Minister Hamid Chitchian said that desalinated water would be provided to 45 million people in 17 provinces through 50 desalination plants, without specifying the costs or funding sources. Initially, water desalinated at Bandar Abbas would be transferred to Kerman province.
Pollution
Water pollution is caused by industrial and municipal wastewater, as well as by agriculture. Concerning municipal wastewater, the bulk of collected sewage is discharged untreated and constitutes a major source of pollution to groundwater and a risk to public health. In a number of cities without sanitary sewerage, households discharge their sewage through open rainwater drains.World Bank: Northern Cities Water Supply and Sanitation Project , p. 29-30
Infrastructure
Drinking water supply Most drinking water in Iran is supplied through modern infrastructure, such as dams, reservoirs, long-distance transmission pipelines - some of which are more than 300 km long - and deep wells. There are 42 large dams under operation in Iran with a combined storage capacity of 33 BCM/year. These dams lose about 200 million cubic meters of storage capacity every year due to sedimentation (0.5-0.75% of their storage capacity). Most dams are multi-purpose dams for hydropower, irrigation, flood control and - in some cases - drinking water supply.Ministry of Energy, Water Research Institute:Sedimentation in the Reservoirs of Large Dams in Iran , 2000 It is estimated that there are as many as 500,000 deep and shallow wells in the country.United Nations:Freshwater and Sanitation Country Profile - The Islamic Republic of Iran , p. 4 Many of those wells are illegal.
An estimated 60,000 traditional Karez (کاریز) systems in the plateau regions of Iran in Yazd, Khorasan and Kerman - are still in use today for irrigation and drinking water supply in rural areas and small towns. The oldest and largest known Karez is in the Iranian city of Gonabad which after 2700 years still provides drinking and agricultural water to nearly 40,000 people. Its main well depth is more than 360 meters and its length is 45 kilometers.
Sewage system
Iran's Energy Ministry reported in January 2021 that some 90% of Tehran's integrated sewage system, a network of 8,000 kilometers of underground tunnels and large sewage treatment facilities, has become operational.
Previously, the majority of Tehran's population had untreated sewage injected to the city's groundwater.Massoud Tajrishy and Ahmad Abrishamchi (2005). "Integrated Approach to Water and Wastewater Management for Tehran, Iran". Water Conservation, Reuse, and Recycling: Proceedings of the Iranian-American Workshop. Washington, DC: National Academies Press.
History and recent developments
Up to 1990 the water and sanitation sector was highly decentralized. Most water and wastewater service provision was the responsibility of municipalities and provinces. This was changed through a fundamental sector reform in 1990 with the ratification of the Provincial Water and Wastewater Companies Law of September 1990.Nikravesh, Ardakanian and Alemohammad, Institutional Capacity Development of Water Resources Management in Iran: UNW-DPC,%202009).pdf#page=169
In September 2003 the Government of Iran and the World Bank agreed on a sector strategy with the targets for improved cost recovery and collection and increased efficiency. It is not clear what were the baseline data in 2003 and to what extent progress has been made to reach these targets. World Bank: Ahwaz and Shiraz Water Supply and Sanitation Project , p. 18 Specifically there were four targets: Working ratio of 0.75 or less by the financial year 2008/09 (the working ratio is defined as operating expenses excluding depreciation and interest/operating revenue). Labor productivity reaching 3 by project completion (expressed as number of staff per 1,000 water connections). Accounts receivables reduced to 4 months by 2008/09. Non-revenue water to reach 27% by 2008/09.
In November 2008 the government announced that it has approved the construction of 177 dams nationwide. Dams in Iran serve primarily for hydropower generation, irrigation and flood control. However, one of the projects will provide drinking water and water for industrial use to the cities of Qom, Golpaygan, Delijan, Saveh, Khomein and Nimvar in the central provinces of Qom, Isfahan and Markazi.
In April 2012, the government launched a project to transfer Caspian Sea water to the central regions of Iran, bringing about 200 million cubic meters (7,062 million cubic feet) of water per year.
In April 2016 Deputy Minister of Energy Sattar Mahmoudi said that six major cities - Bandar Abbas, Shiraz, Kerman, Mashhad and Hamadan - faced acute water shortages, and water resources were under strain in another 450. Parts of Iran have faced droughts for the past 15 years.
Since the 1980s access to urban water supply has increased from 75.5% to 98%. According to one Iranian observer, the water quantity supplied has increased and the quality has improved. He concludes that the reform has been "very successful" and is "an example of best practice" that should "be proposed to other countries.
Challenges