Funafuti, Tuvalu --

Palelei Tovia recalls how Tuvalu islanders used to survive droughts with all-night vigils at wells to collect precious freshwater during the moments it seeped into the shafts.

Tovia, now a schoolteacher, said that during the last bad drought 14 years ago, she stayed up beside a well with her high school friends, telling each other stories to stay awake. As the ocean tide rose, she said, it would push freshwater into the well, and they'd take turns scooping it out, cup by cup.

This year's drought on this isolated atoll in the South Pacific Ocean is equally severe, she said, but with a difference: People no longer turn to well water when the rains don't come. It's too contaminated and salty to drink.

"The situation is bad," said Pusinelli Laafai, Tuvalu's permanent secretary of home affairs. "It's really bad."

Unusually high tides

Experts say the contamination is in part because of development and population growth. But part of it can also be attributed to greater recent tidal fluctuations, resulting in unusually high tides that have mixed salt water in with groundwater.

With climate change expected to push sea levels higher in the decades ahead, Tuvalu could become a bellwether for low-lying islands from the Maldives to Kiribati, where rising oceans threaten to contaminate groundwater to the point where it becomes unable to sustain life.

"Clearly one of the issues for all coral atolls is the limited freshwater available," said Ian Fry, a climate change lecturer at National University of Australia who also works as an international environmental officer for the Tuvalu government.

For now, Tuvalu islanders are not focused on this long-term, existential threat. They are preoccupied with the immediate challenge of providing freshwater to their families.

The atoll of Funafuti is a snaking sliver of coral just 100 yards across in many places and rising no higher than 15 feet. It forms a divide between the ocean and a sparkling lagoon but has grown crowded and polluted despite its idyllic backdrop.

La Niña has settled over the region and deprived Tuvalu of any substantial rainfall for six months. Weather linked to La Niña also has been blamed for the higher tides.

Forecasters say it could be another three months before the rains return.

The situation became so dire that two weeks ago, Tuvalu and neighboring Tokelau each declared a state of emergency. Along with the governments of New Zealand, Australia and the United States, the Red Cross averted a catastrophe by rushing in supplies of bottled water and desalination plants.

But even this has proved barely enough.

At a convenience store that advertises pig feed and milk shakes, cashier Vihui Nia said the drought makes her consider leaving Tuvalu.

"For my kids, I want to take them to a place where there is plenty of water," she said.

Tight water rationing

Nia lives in a household of 12, typical of the extended families in this nation of 10,000. Under a government rationing system enforced after months of drought, the family is allowed to collect just two buckets of freshwater each day - less than a gallon per family member.

Like most others on the island, Nia lines up at a collection point every day between 6 and 8 a.m. to collect her water. She supplements the government ration with the last of the family's rainwater in a catchment tank, but that, too, has almost run dry.

Tuvalu's economy relies mainly on the sale of offshore fishing licenses, income from a trust fund established by donor countries, and the leasing of its Internet domain name - ".tv".

The New Zealand defense force has helped repair Tuvalu's main desalination unit, which sucks 500 gallons of salt water from the lagoon each hour and turns it into freshwater and has brought over its own large desalination unit to increase capacity.

But nobody sees this as a long-term solution. "It's an energy-using system, and importing fuel is a major drain on the economy," Fry said.

To survive, islanders will need to get better about conserving the water they have and improve the rooftop rain catchment systems on which most households rely, he said.