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Natural supplies have run out in the indigenous town of San Felipe Ecatepec in the state of Chiapas, southern Mexico, meaning people must walk for two hours to fetch drinking water, one former local official said.
A nearby bottling plant, run by Mexican company FEMSA, consumed 1.08 million litres of water a day in 2016, according to reports.
Climate change and outbreaks of salmonella have exacerbated the problem.
In response to reports that it was leaving indigenous communities near San Chrisobal without water, FEMSA said it was "committed to the sustainable development of its associates, communities and the environment".
A spokesperson said: “We operate according with the legal framework and under internal processes to guarantee efficient water use.
Coca-Cola has previously come under fire in the country for the negative health impact of its sugary drinks. Mexico has high levels of obesity and more than 70 per cent of the population is overweight or obese.