In southern Iraq, putrid water gushes out of waste pipes into marshes reputed to be home to the biblical Garden of Eden, threatening an already fragile world heritage site.

In a country where the state lacks the capacity to guarantee basic services, 70 percent of Iraq’s industrial waste is dumped directly into rivers or the sea, according to data compiled by the United Nations and academics.

Jassim al-Asadi, head of non-governmental organisation Nature Iraq, told AFP news agency the black wastewater poured into the UNESCO-listed marshes carries “pollution and heavy metals that directly threaten the flora and fauna” present there.

Once an engineer at Iraq’s water resources ministry, al-Asadi left that job to dedicate himself to saving the extraordinary natural habitat, which had previously faced destruction at the hands of former dictator Saddam Hussein and is further jeopardised by climate change.

The pollutants also “indirectly impact humans via the buffalo”, fixtures of the marshes and known for the “guemar” cheese produced from their milk, he said.

According to Nader Mohssen, a fisherman and farmer born in the marshland’s Chibayish district, “the buffalo are forced to go several kilometres into the marshes to be able to drink something other than polluted water”.

And “around the sewerage pipes, most of the fish die”, he added, gesturing to dozens of rotting fish floating on the marsh water surface.

Pollution is only the latest threat to one of the world’s largest inland delta systems.

The rich ecosystem, nestled between the Tigris and Euphrates rivers, barely survived the wrath of Hussein, who ordered the marsh be drained in 1991 as punishment for communities protecting rebel fighters.

The drainage reduced the marshland by half of its 1991 area of 15,000 square kilometres (5,800 square miles).

A former regime official was condemned to death in 2010 for what the UN called “one of the worst environmental crimes in history”, although he reportedly died of natural causes in prison last year.

A few years ago, Mohssen and other marshland residents – several thousand families straddling three provinces in the rural, tribal south and struggling to make ends meet – believed they would see their home flourish again.

Once the canals and earthen dykes built by Hussein’s regime were destroyed, the water returned, and with it more than 200 species of birds and dozens of types of wildlife, some on the verge of extinction elsewhere.

Tourists too – mainly Iraqis – began flocking to the region again to take boat tours and lunch on grilled fish.

But today, the overwhelming stench emanating from the wastewater pipes keeps people away.