A decade ago, the lush marshlands of southern Iraq covered nearly 20,000 square kilometers near the confluence of the Tigris and Euphrates rivers. They hosted hundreds of species of rare birds, mammals and fish. Some Biblical scholars say the marshes were the site of the Garden of Eden. Years of hostilities, though, have turned most of the marshes into desert. This week experts led by the U.S. Agency for International Development will convene in Iraq to study the problem. The stakes are high. Environmental experts say that if a big rehabilitation effort isn’t begun soon, the marshes may be irretrievably lost. “A huge part of the marsh has been desertified,” says geologist Suzie Alwash, cofounder of Eden Again, an environmental NGO based in Washington, D.C.

The marshlands used to be the largest wetlands in the Middle East. They supplied two thirds of the fish in Iraqi markets and 40 percent of the shrimp caught off the coast of Kuwait. Millions of birds migrating between the rivers of western Siberia and northeast Africa also wintered there. In the 1970s, Majeed Rasheed al Hilli, a biologist at Baghdad University, always made sure to take armed guards on field trips to the region for protection–against herds of wild boar. These days boar are rarely seen.

To Saddam Hussein, the marshes and its inhabitants were nothing but a threat. Shiite resistance groups used the maze of waterways and three-meter-tall reeds as cover for their covert operations. In 1991 Saddam struck with artillery, bombs and, by some accounts, napalm–killing thousands. Iraqi soldiers burned down reeds, and engineers built an elaborate system of canals to divert water from the marshes. The 565km-long Saddam River, cut diagonally between the Tigris and the Euphrates, channels water to the Persian Gulf, bypassing the marshes.

Within a decade, 95 percent of the marshes were destroyed. All that remains are portions of Al Hawizeh, which straddles the Iranian border. The smooth-coated otter, striped hyena, grey wolf, bandicoot rat and other mammals are largely gone. So are carp, soft-shelled turtles and other water creatures. “This is one of the major environmental disasters of the 20th century,” says Hassan Partow, a U.N. Environment Program official, “both in terms of its scale and in terms of the speed of change.”

With their livelihoods gone, more than 200,000 Madan marsh dwellers had fled to the cities by 1994. Those who chose to stay behind faced a harsh existence. In the village of Garmat Hassan, on the banks of an algae-ridden Euphrates River tributary, women covered from head to toe in black abayas shuttle children between riverbanks in canoes made from hollowed-out palm trunks. Villagers say the water level has dropped so low it’s possible to walk across the river at some points. What little is left is tainted with industrial pollutants from a nearby power plant and untreated sewage. “We took a sample of this water to a doctor,” says Habib Dubayez Hussein, 75, an elder of the Al Jwaiber tribe, which inhabits the village. “He told us, ‘Don’t let your animals drink it’.” The villagers now buy water from the town of Suq ash Shuyukh, 30km away.

The Madan are eager to see the water return. Since Saddam’s ouster in April, locals have torn down dozens of floodgates and canal walls; satellite photos show that 15,000 hectares north of Basra have been flooded. In May, Hamid Abdul Razaq, 48, pooled his money with other villagers near Basra to rent a backhoe. In a few hours, canal water flooded his fields of okra and tomato. “This is the first step,” he says. “We need more water.” Such ad hoc fixes are risky. Too much water washes away salt that’s dried on the ground; too little creates saline lakes. “The different parts of the marsh need to be patched together,” says Alwash of Eden Again, “or else you won’t get the fish back or the birds back.”

Time is running short. Scientists want to replenish the marshes with fresh wildlife from Al Hawizeh, but this marsh, too, is drying up. “A verse in the Qur’an says, ‘Every living thing is created from water’,” says Hussein. “We are hoping that the water will come back.”