Its 46 million people face rising temperatures, chronic water shortages and year-on-year droughts, in a country intensely impacted by climate change.

The impact has been felt most acutely in the south, where reduced flow is fuelling water pollution and the rapid spread of algae.

The once-mighty Tigris and Euphrates, which have irrigated the country for millennia, originate in Turkey, and authorities in Iraq have repeatedly blamed upstream Turkish dams for significantly reducing river flows.

"In recent weeks, the Euphrates has seen its lowest water levels in decades," particularly in the south, said Hasan al-Khateeb, an expert from the University of Kufa.

Iraq currently receives less than 35 percent of its allocated share of the Tigris and Euphrates, according to authorities.

To maintain the flow of the Euphrates, Iraq is releasing more water from its dwindling reservoirs than it receives, a measure that may not be sustainable.

Khaled Shamal, spokesman of the water resources ministry, said that water reserves in artificial lakes "are at their lowest in the history of the Iraqi state".

Reserves have fallen from 10 billion cubic metres in late May to less than eight billion, which is less than eight percent of their capacity.

Reduced water flow has resulted in poor water quality and poses a threat to the Euphrates ecosystem.

Khateeb said that releasing water from ageing reserves to feed the river has led to the spread of algae, which depletes oxygen and endangers aquatic life.

The environment ministry warned Sunday of increased bacterial pollution and large areas of algae in Karbala province.

Authorities have also warned of "very poor" water quality in the neighbouring province of Najaf.

In Lake Najaf, an AFP photographer said the once-lush lake has been largely reduced to stagnant pools scattered across the basin.

In Nasiriyah, the capital of Dhi Qar province, an AFP photographer saw water hyacinth blooming in the Euphrates.

Water hyacinths, present in Iraq since the 1990s, have become more prevalent due to the low water flow, which also worsen their impact, according to Khateeb.

This invasive plant can absorb up to five litres of water per plant per day and obstructs sunlight and oxygen, which are vital for aquatic life.

The environment ministry said Monday it purifies water to strict standards, and the quality is so far "acceptable" and safe for use in cities in south and central Iraq.