Who gains from saving nature
Ledger 1 : 33 — For each dollar financing nature-based solutions in 2023, about $33 financed activities harmful to nature. (UNEP)
Cases / Water use · Iran · 1968–2025

Land subsidence on the Tehran plain and across Iran

Nature's voice · report
Between 1984 and 2011 my groundwater under the Tehran region fell 12 m, while the wells drawing on it rose from just under 4,000 in 1968 to more than 32,000 in 2012, according to GFZ.
Did nature suffer? Yes. Harm is on record.
Recorded
  • Between 2003 and 2017 three areas of my Tehran region sank in some places by more than 25 cm per year, according to GFZ; some of my groundwater basins were "irreversibly damaged and can no longer store as much water". GFZ German Research Centre for Geosciences (via idw)
  • About 56,000 km² of my surface, 3.5% of Iran, subsided between 2014 and 2020, over 3,000 km² of it at more than 10 cm per year, according to Haghshenas Haghighi and Motagh (2024). Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh)
  • At least 60% of the subsidence measured across my aquifers between 2015 and 2023 is inelastic, meaning the compaction is irreversible, according to Payne et al. (2025). JGR Solid Earth 130(9) (Payne et al.)
  • About 133 km³ of my nonrenewable groundwater had been depleted by 2019, and 16 of 30 subbasins had a "very high salinity hazard", according to Noori et al. (2021). PNAS 118(25) (Noori et al.)
What the record lacks: 5 none on record · 1 not disclosed · 1 disputed · 2 unclear See the gaps

Satellite radar studies measured about 56,000 km² of Iran, 3.5% of the country, sinking between 2014 and 2020, with the Tehran plain, Rafsanjan and Kerman among the fastest-sinking areas. In August 2025 the National Cartographic Center said its national subsidence atlas had been supplied to agencies in confidential reports.

≈ 56,000 km² estimateLand area subsiding in Iran, 2014–2020
Estimate from Sentinel-1 satellite radar: 3.5% of Iran, of which over 3,000 km² sank faster than 10 cm per year (Haghshenas Haghighi & Motagh, Science Advances, 2024).

Status As of August 2025: the National Cartographic Center described its national subsidence atlas as confidential; the latest published studies cover satellite data to 2023, and no remediation budget or court case is on record.

What?
Groundwater pumping has been followed by land subsidence over about 56,000 km² of Iran, including the Tehran plain, where some areas sank more than 25 cm per year between 2003 and 2017; a large share of the compaction is irreversible. Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh)
Where?
The Tehran plain (southwest Tehran, Shahriar, Districts 18–19), Imam Khomeini International Airport, Rafsanjan and Kerman, and 265 of Iran's 429 counties. Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh)
When?
Wells in the Tehran region grew from just under 4,000 in 1968 to more than 32,000 in 2012; satellite studies cover 2003–2017, 2014–2020 and 2015–2023; official statements from 2017 to August 2025. GFZ German Research Centre for Geosciences (via idw)
Who?
Gained
Lost
Harmed
Why?
The studies attribute subsidence to groundwater withdrawal; 77% of subsidence faster than 10 mm per year is associated with agriculture (Payne et al., 2025). JGR Solid Earth 130(9) (Payne et al.)
How?
Radar interferometry (InSAR) from Envisat, ALOS, TerraSAR-X and Sentinel-1 satellites measured ground movement; the Cartographic Center's national atlas of the results is held in confidential reports. Radio Farda
In proportion Tehran province accounts for more than 20% of Iran's GDP, and agriculture 2% of its gross value added. Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh)
6 of 6 questions answered from the record

What happened

The record, in order.

Researchers at the GFZ German Research Centre for Geosciences (Mahdi Motagh and Mahmud Haghshenas Haghighi) measured three areas of the Tehran region sinking "in some places by more than 25 cm per year" between 2003 and 2017, with several metres of total subsidence, using nine data sets from the Envisat ASAR, ALOS PALSAR, TerraSAR-X and Sentinel-1 satellites. The study appeared in Remote Sensing of Environment (DOI 10.1016/j.rse.2018.11.003). GFZ's release of 6 December 2018 stated that some groundwater basins were "irreversibly damaged and can no longer store as much water", and gave the number of wells in the Tehran region as rising from just under 4,000 in 1968 to more than 32,000 in 2012, with the Tehran groundwater level falling 12 m between 1984 and 2011.

Haghshenas Haghighi and Motagh published a national study in Science Advances on 10 May 2024, using more than 6,000 Sentinel-1 images from 2014 to 2020 at 100 m resolution. It found about 56,000 km² (3.5% of Iran) subsiding, over 3,000 km² of it at more than 10 cm per year, with a median rate of 1.8 cm per year. It estimated annual groundwater depletion from confined and semi-confined aquifers at 1,737 MCM (1.7 BCM), "comparable to the maximum capacity of the five dams supplying Tehran", of which 101 MCM per year in Tehran province. About 14 million people lived in directly affected areas and 0.9 million in high-risk areas, about 350,000 of them in Tehran province and 290,000 in Alborz.

The same study counted infrastructure in subsidence zones: about 1,380 km (15%) of roughly 9,500 km of railway lines, including segments of the Tehran–Garmsar and Garmsar–Mashhad lines; 4 of 7 Tehran metro lines and the only Isfahan metro line; 580 km of 5,100 km of motorways (11%); and 8 of 61 large and medium airports, "including the Tehran International Airport, with more than 8 million annual passengers" (the paper's wording), plus the Isfahan and Urmia international airports. It noted that Tehran province accounts for "more than 20% of Iran's GDP" while agriculture contributes 2% of the province's gross value added, "at the cost of major subsidence risk to the population and infrastructure". A second national study, by Payne et al. in JGR Solid Earth (published online 27 August 2025), identified 106 basin-scale subsidence areas, 31,400 km² (1.9% of the country) sinking faster than 10 mm per year, a maximum of about 340 mm per year in Rafsanjan, 77% of subsidence above 10 mm per year associated with agriculture, about 650,200 people at medium or higher risk, and an inelastic (irreversible) share of at least 60%.

In January 2019 the Associated Press reported that German scientists estimated the land under Imam Khomeini International Airport sinking about 5 cm per year, and that subsidence near Tehran reached up to 22 cm per year according to Iran's cartography department. Ali Beitollahi, an official of the Road, Housing and Urban Development Research Center of the Ministry of Roads and Urban Development, told the AP that Tehran's oil refinery, a key highway, automobile plants and railroads sit on sinking ground, with about 2 million people living in the affected area. In May 2019 he told the newspaper Taadol that the airport subsided about 4–6 cm per year, "not critical for now", southern Tehran about 25 cm per year, and the Isfahan and Kerman airports at "very high" rates without figures. Phase 1 of an airport subsidence monitoring programme had been completed and phase 2 had started; about 60 active airports needed studies.

In April 2025 Mehdi Pirhadi, chair of the Health, Environment and Urban Services Commission of the Tehran City Council, said a national surveying organisation report put subsidence in some parts of Tehran at 31 cm, and that the president had cited 36 cm near deep wells. On 31 August 2025 Radio Farda reported that Eskandar Seydaei, head of the National Cartographic Center, said an atlas of Iran's subsidence had been compiled and supplied to agencies in confidential reports, correspondence and files; he gave the highest rate as 31 cm in the Bahraman plain (Kerman), about 30 cm in one Tehran area and about 20 cm in District 18. Mohammad Aghamiri of the Tehran City Council's urban-development committee said Tehran's subsidence statistics were confidential.

  1. 1968Wells in the Tehran region number just under 4,000; more than 32,000 by 2012
  2. 1984Start of the 1984–2011 period in which the Tehran groundwater level fell 12 m
  3. 2003Start of the GFZ multi-sensor radar study of the Tehran region (2003–2017)
  4. 2017Iran Railways says no subsidence within the railway right-of-way (15 Oct)
  5. 2018GFZ release on Tehran subsidence (6 Dec)
  6. 2019AP reports on subsidence under Imam Khomeini airport (24 Jan); airport subsidence monitoring programme in phase 2 (28 May)
  7. 2024Science Advances national subsidence study (10 May)
  8. 2025Tehran City Council member cites 31 cm (7 Apr); Payne et al. national study (27 Aug); Cartographic Center describes subsidence atlas as confidential (31 Aug)

What was said

Claims, in the words of those who made them.

“Rates (for subsidence) are very high and in many instances it's happening in densely populated areas,”

“In European countries, even 4 millimeters (0.15 inches) of yearly subsidence is considered a crisis,”

“The loss in volume is permanent and a consequential damage of unrestrained groundwater exploitation.”

“not critical for now”

Ali Beitollahi, head of the seismology department, Road, Housing and Urban Development Research Center (on conditions at Imam Khomeini International Airport) · 28 May 2019 · translated from Persian · Taadol

“we have not seen any cracks or subsidence within the country's railway right-of-way”

Maziar Yazdani, technical deputy of Iran Railways · 15 October 2017 · translated from Persian · Taadol

“Tehran's subsidence statistics are confidential and I cannot state them”

Mohammad Aghamiri, head of the urban-development committee, Tehran City Council · 31 August 2025 · translated from Persian · Radio Farda

“subsidence has no instant solution; the only lasting solution is stopping excessive water extraction”

Eskandar Seydaei, head of the National Cartographic Center · 31 August 2025 · translated from Persian · Radio Farda

Where accounts differ

Each party's account, side by side, with its source. The record does not settle these points; it shows them.

Whether railway lines are affected by subsidence (the statements use different definitions: railway right-of-way versus subsidence zone)
Government and regulators
Iran Railways, technical deputy (15 October 2017)

No cracks or subsidence within the railway right-of-way; one subsidence case intersecting a line reported by a deputy minister.

Taadol
Researchers
Haghshenas Haghighi & Motagh, Science Advances (2024)

About 1,380 km (15%) of about 9,500 km of railway lies in subsidence zones, including segments of the Tehran–Garmsar and Garmsar–Mashhad lines; 54 of 310 railway stations are in subsidence zones.

Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh)

How it looked

What was shown, beside what was recorded.

Shown

  • Iran Railways' technical deputy reported no cracks or subsidence within the railway right-of-way, with a 100 m buffer monitored 24 hours a day; a deputy minister reported one subsidence case intersecting a line.
    Iran Railways (Taadol, 15 October 2017) · Taadol
  • Conditions at Imam Khomeini International Airport were described as not critical for now, with a monitoring programme under way.
    Ali Beitollahi, Ministry of Roads and Urban Development research centre (Taadol, 28 May 2019) · Taadol
  • The national subsidence atlas was described as supplied to agencies in confidential reports, correspondence and files.
    National Cartographic Center (Radio Farda, 31 August 2025) · Radio Farda

Recorded

Who gained

Money that reached nature, beside money that stayed elsewhere.

Reached nature or the ground

Not published
Budget for subsidence remediation or infrastructure protection—
None on record. In 2019 an official said a budget line for subsidence monitoring should be allocated; no amount was stated.

Gained elsewhere

Not totalled
Currency: USD · Window: n/a. All figures cover the same period. * Estimate built from cited figures.

Responses on record

  • Iran Railways (15 October 2017): Its technical deputy said no cracks or subsidence had been seen within the railway right-of-way, monitored 24 hours a day over a 100 m buffer. · Taadol
  • National Cartographic Center of Iran (31 August 2025): Its head said the subsidence atlas was compiled and supplied to agencies in confidential reports, correspondence and files. · Radio Farda

In court and with insurers

Every proceeding and every insurer decision on record.

Lawsuits and rulings

No court case on record. No court has ruled on this case.

Insurers

No insurer decision on record.

What nature saw

Outcomes measured on the ground, and nature's note.

Nature's report opens this page. Below: further outcomes measured on the ground.

Area subsiding
≈ 56,000 km²
3.5% of Iran, 2014–2020; over 3,000 km² at more than 10 cm per year
Irreversible share
≥ 60%
Inelastic share of subsidence, 2015–2023 data
Aquifer depletion
1.737 BCM/yr
Confined and semi-confined aquifers, 2014–2020
Tehran groundwater level
−12 m
Fall between 1984 and 2011

What we don't know

Undisclosed, unproven, untried: recorded as data.
No court caseKey earnings undisclosed

Money

  • None on record Budget for subsidence remediation or infrastructure protection — None on record. In 2019 an official said a budget line for subsidence monitoring should be allocated; no amount was stated.

Court

Accounts

  • Disputed Whether railway lines are affected by subsidence (the statements use different definitions: railway right-of-way versus subsidence zone)

Record

  • Not disclosed Not disclosed: the National Cartographic Center's national subsidence atlas, which its head said was supplied to agencies in "confidential reports, correspondence and files" (August 2025); a Tehran City Council committee head also described Tehran's subsidence statistics as confidential.
  • None on record None on record: a budget for subsidence remediation or infrastructure protection; an official said in 2019 that a budget line for monitoring should be allocated.
  • Unclear Unclear: whether the 31 cm of subsidence cited for parts of Tehran in April 2025 is an annual rate or a cumulative depth; the article does not say.
  • Unclear Unclear: the time unit of the figures of about 30 cm (one Tehran area) and about 20 cm (District 18) given by the National Cartographic Center's head in August 2025.
  • None on record None on record: legal proceedings over subsidence damage.
  • None on record None on record: insurance for subsidence damage.

Did the harm stop?

None on record. The latest satellite data cited cover 2015–2023, and the head of the National Cartographic Center said in August 2025 that the only lasting solution is stopping excessive water extraction.

Who paid?

The aquifers and land surface of the Tehran plain and of 265 of Iran's 429 counties, where the loss is recorded as largely permanent. Owners and users of the railways, metro lines and airports in subsidence zones carry the exposure; no remediation budget or payer is on record.

Sources

Voices on record: — Company or project— Government and regulators— Courts✓ Press and investigations— Communities and civil society✓ Researchers

Press and investigations

  1. In Iran, parched lands hollowed by water pumping now sinking
    Associated Press (via VOA) · 2019-01-24
  4. Land subsidence in Tehran reached 31 cm
    Aftab News (citing ISNA) · 2025-04-07
  5. Confidential subsidence atlas of Iran
    Radio Farda · 2025-08-31

Researchers

  1. Tehran sinking (release on Haghshenas Haghighi & Motagh, Remote Sensing of Environment)
    GFZ German Research Centre for Geosciences (via idw) · 2018-12-06
  2. Uncovering the impacts of depleting aquifers: A remote sensing analysis of land subsidence in Iran
    Science Advances 10, eadk3039 (Haghshenas Haghighi & Motagh) · 2024-05-10
  4. Anthropogenic depletion of Iran's aquifers
    PNAS 118(25) (Noori et al.) · 2021-06-14

Connected cases

Related matters, and cases linked to this one through the same organisations, with the role each played in both.
Terms used on this page

Science and environment

Groundwater
Water held underground in soil and rock, drawn through wells.
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