SAO PAULO, Feb. 12 (UPI) -- Brazil's largest city is facing a water shortage this year unlike it has seen in decades -- a potential disaster scientists have warned about as far back as the 1980s.

The metropolitan area of Sao Paulo, the world's 12th-largest metro population at more than 20 million, is served by two main natural water systems -- the Cantareira and Alto Tiete reservoir networks, which barely have any water in them, The Guardian reported this week. The Cantareira is only 5 percent full, and the Tiete is at less than 15 percent of capacity.


This is an issue that water conservation advocates and scientists have warned about for decades. The Brazilian government has undertaken moderate efforts over the last 25 years to improve the drought conditions but they have had a limited impact.

Experts say the drought could be catastrophic, due to aggravating factors like water management flaws and a culture of waste and pollution, and bring the Americas' largest metropolitan population to the brink of collapse. It's the most severe drought in Sao Paulo in 80 years, National Public Radio reported.

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"Sao Paulo was known as the drizzle city, lots of drizzle. Not anymore," said Augusto Jose Pereira Filho, professor of atmospheric science at Sao Paulo University. "Now it is kind of a desert."

Any kind of a water shortage in Brazil might seem strange to some, since the country is rife with rainforests, and annual precipitation levels are typically well above the global average. The problem, scientists say, is not so much the collection of water as it is the overuse, neglect and pollution of the resource. Factor in rain patterns that are below normal for the current rainy season, which began in November, and Sao Paulo is confronted with the current predicament.

Scientists have predicted that, given the current consumption rate and lack of rainfall, water supplies for the Sao Paulo region might only last as many as six months. That means the water may run out before the next rainy season begins. Last May, Brazil's southern coast was hit by torrential rains and officials are hoping to see a repeat this year to help fill the reservoirs.

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State officials recently announced a potentially drastic water-rationing program, which would permit residents only two days a week to use water -- and five days without -- just in case rains don't fill the reservoirs for the next six weeks.

Government officials have long been aware of the potential for disaster regarding water management, but action urged by advocates has largely been ignored. In 1992, Sao Paulo's governor launched a program to clean up the heavily polluted Tiete River, but 23 years -- and $1.5 billion later -- the project is still far short of complete.

Part of the problem, experts say, stems from Brazil's impoverished population. While the government can impose water limits and regulations to offset the problems, areas of the poor can often consume water at rates that cannot be monitored or restricted by officials. Another issue aggravating the matter, some researchers say, is climate change -- which they believe is occurring due to rising temperatures, deforestation and the below average rainfall they are seeing in Brazil.

The challenges and threats of Brazil's imminent water shortage are not only frightening due to its most immediate impact. Some government officials fear what may also begin to happen further down the road, such as residents consuming polluted water or turning to violence and thievery when wells finally run dry.

"That scenario is really scary," Pereira said. "Water is very important; it's a fundamental resource for us."

Some of Sao Paulo's residents accuse the government of turning a blind eye to the problem. Last summer, the nation hosted the World Cup -- a time when state officials did not want to take substantial action. Now, they say, it's a disaster.

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Rio de Janiero, situated about 250 miles east of Sao Paulo, is getting set to host the 2016 Summer Olympic Games next year -- a situation that certainly could impact the southern coast's water sustainability.