A Frenchman who can see water beneath the Sahara

Out here in the sandy moonscape of eastern Chad, you don't expect to see a diminutive Frenchman with an Indiana Jones hat marching around, muttering, and staring at his global-positioning device.

But Alain Gachet has come here to outdo generations of witch doctors, water diviners, and PhDs. He aims to pinpoint, with scientific certainty, the right places to dig the costly wells that pull precious water from beneath the sand.

And this isn't some academic exercise. About 200,000 refugees have fled to Chad from Sudan's violent Darfur region. They each need four gallons of water a day, the United Nations says - or a total of about 25 swimming pools in a land that gets no rain for months on end. At a time when nearly 1 out of every 5 people in the world is without adequate drinking water, Mr. Gachet could help save countless lives.

Gachet says he's up to the task, due, oddly enough, to the space shuttle and the end of the cold war. Working in his 15th-century chateau in France, he fused together an unprecedented set of maps, including newly released topo- graphic ones from the shuttle and previously unavailable radar ones that peer 20 yards underground. Now he's put the data into his GPS device. When he says, "Dig here!" aid workers listen.

So far, the half dozen wells drilled under his direction have hit water. His data has also been key, UN officials say, in picking new sites for refugee camps. Several older camps were set up far from water, causing great complications for refugees and aid workers.

Gachet's work is "a revolution - in terms of water, the most important thing to happen in 20 years," says Ben Harvey, a water specialist for the International Rescue Committee at the Oure Cassoni refugee camp near the northern Chadian town of Bahai.

Mr. Harvey notes that the site for the Oure Cassoni camp, home to about 17,000 refugees, was chosen because it's near a small lake. Yet it's also dangerously close to the Chad-Sudan border, making the refugees susceptible to further attacks. Janjaweed militia, who've been implicated in the killing of 30,000 to 50,000 Sudanese civilians in Darfur, regularly come to water their horses at the lake. It makes Oure Cassoni a risky place - but one that, at least, has water. Gachet's technology is allowing camps to be set up in safer locations away from the border.

Even now, during the rainy season, good water is hard to find. Rivers, for instance, may be full, but they can be contaminated by animal carcasses. A recent World Health Organization survey found that 6,000 to 10,000 people are dying in Darfur each month, citing lack of clean water as one of the major reasons.

Meanwhile, the United Nations Security Council on Saturday passed a new US-sponsored resolution, saying that Sudan hasn't fully complied with previous resolutions and threatening sanctions against Sudan's leaders and its burgeoning oil industry if the government doesn't quell the violence in Darfur.

But far from the geopolitics of UN debates is the reality of desert geology.

In general, water-divining experts, known as hydrologists, succeed anywhere from 65 percent to 80 percent of the time. Out here, in the nearly all-sand terrain of eastern Chad, that rate has been as low as 50 percent. And big wells needed for refugee camps are expensive - about $6,000. If wells fail, water has to be trucked in. Tankers cost $350 a day and often get stuck in mud or sand.

That's where Gachet and his GPS come in. He's a geologist by training who spent two decades as an explorer for a French oil firm. But this tiny cyclone of a man - who's been known to traipse through jungles to talk to Congolese pygmies or skip work to dig up artifacts in ancient African villages - decided to set out on his own.

His timing, he says, was perfect. As the cold war ended, lots of secret technology became available to civilians: GPS devices, satellite maps, computer-mapping software, among others. For all of it Gachet is enthusiastically grateful to one man. "I thank God every day for Ronald Reagan," he declares to just about anyone who will listen in a UN office in Chad. He says Mr. Reagan's defense build-up spawned new technologies and helped end the cold war.

With this technology, and from the comfort of Provence, he can hunt for gold deposits in Africa or spot leaks in pipelines for oil-company clients.

And in Chad, based on Gachet's data, the UN has rejected seven sites for new refugee camps. "It's saved us months of running around and drilling test wells," says Geoff Wordley, a senior UN emergency officer. Without Gachet's data, he adds, "We might as well be using divining rods."

When one camp, called Am Nabak, became unsustainable because of a lack of water, Gachet used his maps to find a new site 12 miles away. It's got plenty of water.

The topographical maps also enable Gachet to spot where dams can be built to create reservoirs to help sustain refugees over the long run. The UN has now asked Gachet to map more of eastern Chad.

Still, there are limits to his data. The biggest is that it can't tell how much water is at a site - just that there is water there. That means aid workers never know how long one of Gachet's wells will continue to produce water.

Nonetheless, the potential could help in other places, experts say, as water becomes a major global concern. Consider that 1.1 billion people can't get safe drinking water, according to the UN. Or that all across China, "weather modification bureaus" reportedly use planes, antiaircraft guns, and rocket launchers to put chemicals into clouds to coax them to shower farmers' fields. Or that the American West is in the midst of one of the worst droughts in 500 years, which has caused forest fires and great destruction.

To tackle these problems, says the ever upbeat Gachet, "All we need is more imagination" to put the new technology to good use.