The Tigris River is drying up. Iraq’s water reserves hit 80-year lows in August 2025, and the country’s Ministry of Water Resources warns the river could effectively run dry by 2040. What was once the lifeblood of Mesopotamian civilization is now shrinking under the combined pressure of upstream dams, climate change, and pollution, with consequences rippling across ecosystems, farms, and cities.
How Much Water Has Been Lost
The scale of the decline is visible from space. In October 2025, Lake Tharthar, Iraq’s largest reservoir and a critical buffer fed by the Tigris, dropped to its lowest level in the satellite record dating back to 1992. Gauge data showed water levels at their lowest point since the reservoir was built in 1958, falling to 38.5 meters above sea level, more than 20 meters below the peak observed after floods in 1993.
Lake Habaniya, another key reservoir, tells the same story. By September 2025, it was so depleted it could no longer discharge water back to the Euphrates as it normally does. Its stored volume fell to roughly 511 million cubic meters, just 15% of its total capacity of 3.3 billion cubic meters.
Why the River Is Shrinking
Three forces are working against the Tigris simultaneously. The first and most politically charged is upstream dam construction, particularly in Turkey. Turkey’s large-scale water development projects, including the Ilisu Dam on the Tigris, have dramatically reduced the volume of water entering Iraq. Modeling shows that cities like Mosul could experience extreme low-flow conditions in as many as 87.5% of years, with inflow to the Mosul reservoir dropping to as low as 135 cubic meters per second.
The second force is climate change. Rainfall across the region has declined, and temperatures have risen, increasing evaporation from reservoirs and soil alike. The region does occasionally get sudden bursts of rain. A record-breaking atmospheric river in March 2019 briefly refilled reservoirs. But these events are becoming less reliable and cannot offset the long-term drying trend.
The third factor is Iraq’s own aging and inefficient water infrastructure. Internal irrigation projects, poor drainage systems, and a lack of modern water management mean that even the water Iraq does receive is used wastefully.
What Is Happening to the Water Quality
Less water flowing through the river means pollutants become more concentrated. Salinity in the Tigris rises dramatically as the river moves south through Iraq, measuring around 280 parts per million at the Turkish border in the northwest and climbing to 1,800 ppm downstream near Basra. That level of salt makes water increasingly unsuitable for drinking or irrigation without treatment.
The pollution goes beyond salt. Agricultural runoff, untreated sewage, household waste, and industrial discharge all flow into the river. In some areas, vegetables are irrigated directly with sewage water. This contamination has led to persistent outbreaks of bacterial, viral, and parasitic waterborne diseases across the population. Cancer rates in Iraq have also risen since the early 1990s, linked in part to depleted uranium contamination from decades of conflict, which has leached into water sources.
Farming and Food Security
Iraq was once a grain exporter. The country had planned to resume grain exports by 2017, but the water crisis turned that goal into a distant memory. Iraq is now a grain importer, dependent on foreign supply for a staple it once grew in abundance.
As water from the Tigris and Euphrates has diminished, farmland across the country has shrunk. Many farmers in both river basins have been unable to grow crops for years. Some have simply walked away from dried-out fields. The country’s agricultural import bill has ballooned as a result. Meanwhile, Turkey’s agricultural production value has increased by 90% over the same period, compared to just 1.4% for Iraq. The upstream-downstream power imbalance is stark: Turkey builds dams and grows more food, while Iraqi farmers lose their livelihoods.
The Mesopotamian Marshes Are Disappearing
At the southern end of the Tigris and Euphrates system lie the Mesopotamian Marshes, one of the most ecologically significant wetlands in the Middle East. These marshes have lost an estimated 84% of their permanent area. Open water within the marshes has decreased by 90%. By 2003, the remaining marshland had been reduced to just 7 to 10% of its original size compared to 1978, the result of deliberate drainage campaigns under the former Iraqi government combined with declining river flows.
The biodiversity at stake is irreplaceable. The Hawizeh Marsh alone hosts around 40 breeding bird species and over 90 migratory species. It is the only known global habitat for Maxwell’s otter, an endangered subspecies of the smooth-coated otter found nowhere else on Earth. The marshes are also home to the Basra reed warbler, the Iraq babbler, and several other bird species with extremely limited ranges.
Six fish species found in the marshes are geographically restricted to this system, including the Mesopotamian binni, the Euphrates catfish, and the tiger barbel. Four wild mammal species depend on the wetlands, including the long-tailed bandicoot rat, an endemic species already classified as endangered. As the marshes shrink, these species lose habitat they cannot find elsewhere.
What Comes Next
The trajectory is clear and grim. Iraq sits at the bottom of a river system controlled largely by its neighbors. Turkey holds the most leverage through its extensive dam network, and there is no binding international agreement that guarantees Iraq a minimum water share. Climate projections for the region show continued warming and reduced precipitation through mid-century.
If the Iraqi government’s own warning proves accurate, the Tigris could lose functional viability by 2040. That does not necessarily mean the riverbed will be completely dry in every stretch, but it means the river would no longer carry enough water to sustain the agriculture, drinking supply, and ecosystems that tens of millions of people depend on. For a river that helped give rise to the earliest human civilizations, the decline is happening with remarkable speed.