At the edge of the Kalahari Desert, the world's largest oasis shimmers improbably near the arid sands.
The Okavango River, which rises in Angola, flows down through Namibia into Botswana to create a dazzling chain of lagoons and pools. Thousands of birds, lions, elephants, and 100,000 people depend on the water to survive in what is the planet's largest delta.
But now, Botswana worries, its neighbor Namibia may turn the sanctuary into dust.
Namibia, the driest African country south of the Sahara, wants to drain what it says is a fraction of the 5,800-square-mile Okavango Delta to offset a five-year drought. Its plan for a 155-mile pipeline would tap 20 million cubic meters out of a total 10 billion flowing into the delta yearly.
Experts in Botswana say this could ruin what is a pristine World Heritage Site and wreck the tourism that is the country's third-largest foreign-currency earner.
"Here in Africa, shortage of water is a huge issue," says Moremi Sekwale, Botswana's chief representative to Okacom, a joint commission dealing with the dispute. "Damage to the delta is unacceptable, no matter how small."
More precious than diamonds
It is logical that water would provoke a dispute in this normally amicable corner of Africa. Water - not oil, gold, or diamonds - is Africa's most valuable resource. It is likely to become the most-pressing issue in decades to come as droughts and growing populations empty the taps.
Egypt and Sudan are among those who have sparred over water. Mozambique accuses its neighbors of not sharing theirs. Signs asking residents to conserve water are common in the more-arid countries. So precious is the resource that South Africa named one of its most capable administrators to head its water ministry.
The Okavango squabble comes amid territorial tensions between Botswana and Namibia over a tiny island, Sedudu. That matter has been referred to the International Court of Justice in The Hague. Officials hope the water-pipeline issue will be resolved with greater ease.
Botswana's concern is that the floods that normally feed the delta have not come down from Angola's highlands for more than five years. This means there is even less water to spare.
The situation has gotten so grave that a tributary, the Thamalakane River near the delta's safari capital, Maun, has dried up - and with it the fish and tswii aquatic weed on which villagers have subsisted for generations.
Thorn bushes six feet tall now grow in the dusty river bed. There are no more river reeds to build traditional huts or weave baskets. Grazing land and gardens have withered away.
The thought that Namibia might take even more water from the Okavango River angers local residents. Among them is Lewanika Machangane, a Maun father of five who has worked as a game ranger for 15 years.
"If the delta is dry, there are no animals," he says. "If there are no animals, there are no tourists. If there are no tourists, I lose my job."
Just a drop in the bucket?
Namibia insists that the water taken would be just a small amount.
"Our demands are insignificant if one considers how much water flows into the delta," Piet Heyns, a director of Namibia's agriculture and water ministry, said recently.
The problem is not how much water is taken, however, but where it it taken from, says Lars Ramburg, director of Botswana University's Okavango Research Center in Maun.
Even the loss of a fraction of an inch could impact wildlife, he says, adding: "The magnitude of the potential damage is still unknown."
"The question is not that only 1 percent of water will be lost but where it would be [lost]. Maybe 150 square kilometers [90 square miles] of flood plain would be lost. This would be mainly on the fringe, where most of the people live."
Under a water protocol signed by Southern African Development Community states, Namibia has the right to use the water in its territory. But it must carry out an assessment study proving there will be no harm to fellow basin states Angola and Botswana.
A study was hastily done by Namibia recently, but has yet to be made public.
The three countries are trying to resolve the dispute in Okacom, the joint commission. Despite protestations on all sides that communications are good, they have yet to find common ground.
Search for solutions
Namibia is reluctant to explore desalination of seawater from its coast - an option proposed by Botswana's scientists - saying that would cost six times more than the estimated cost of the Okavango pipeline.
For a while, it looked as if recent rains might solve the problem. The Namibian government said it now had enough water for four or five years. But earlier this month, the Cabinet recommended that assessment continue on the pipeline idea.
"We still need to talk," Mr. Sekwale says.