One of India's biggest cities is running out of water

One of India's largest cities is running out of water, forcing residents to wait in long lines to receive water from government tanks and leading some businesses to shut down operations.

Chennai, the capital of the Indian state of Tamil Nadu, is India's sixth largest city, according to 2011 census data.

The southern city was voted by Lonely Planet as one of the top 10 cities in the world to visit in 2015, and was rated the safest city in India in 2016. According to the country's tourism ministry, Tamil Nadu attracted 4.72 million foreign tourists in 2016, higher than any other Indian state.

But the city has been experiencing a major heatwave in recent weeks, with temperatures soaring to 42 degrees Celsius (107 degrees Fahrenheit) on Sunday.

Four main water reservoirs in Chennai have run completely dry, according to the BBC, forcing residents to wait in line for hours to get water from government trucks carrying tanks and causing some businesses to close. Lakes and surrounding bodies of water have also began to dry, causing a buildup of dead fish.

According to the BBC, officials are urgently searching for alternative water sources and are beginning to extract water from underground mines. Many businesses have asked staff to work from home to conserve resources, it added.

According to NDTV, the city's water authority has cut the city's piped water supply by 40 percent, leaving people with barely enough water to bathe or drink.

Tamil Nadu Congress party leader KS Alagiri urged the government to declare an emergency in Tamil Nadu in order to receive necessary funding for drought relief.

Niti Aayog, a government think tank, said in a 2018 report that India is facing its worst water crisis in history. More than 600 million people are facing "acute" water shortages, and 21 Indian cities, including Chennai, are expected to run out of groundwater by 2020.

"Critical groundwater resources — which account for 40% of our water supply — are being depleted at unsustainable rates," it said.