Updated

Sparse rains, increased use of water and unusually hot weather have aggravated the worst drought to hit Brazil's most populous city in more than 80 years and water experts say its water supply might be in danger.

The reservoirs and rivers that provide water to millions in this city have received less rainfall than hoped during the first weeks of the wet season, raising fears that they won't be replenished as hoped.

The Cantareira water system, the largest of six that provide water to some 6 million of the 20 million people living in the metropolitan area of Sao Paulo city, is at 6 percent of its capacity of 1 trillion liters (264 billion gallons), water utility Sabesp said Friday on its website.