At issue is the allocation of water from the Cauvery River, also known as the Kaveri, which originates in the southern Indian state of Karnataka, where Bangalore is located, and flows into neighboring Tamil Nadu. The water-sharing agreement between the two Indian states has been a source of controversy for more than a century.
In 2007, a government panel established an official allocation system that Karnataka has long argued favors farmers in Tamil Nadu. The Supreme Court had directed the Karnataka government to release water to Tamil Nadu in the coming days, sparking the protests. Protesters are not only concerned about water for irrigation, but drinking water supplies as well.
Disputes over control of water supplies are not uncommon around the world. Egypt, Sudan and Ethiopia have quarreled for years over dams and other water-control measures along the Nile. In the United States, the Colorado River is at the center of a tug-of-war between the needs of agriculture and growing cities.
India is now the latest flash point in water-use battles, which some experts believe could become more acute worldwide as climate change boosts temperatures and influences weather patterns.
"People should not take law in their own hands," said Siddaramaiah, who goes by one name.
Chanting “we will give blood, but not Cauvery,” protesters took to the streets Monday, torching hundreds of buses and stores and clashing with police. At least two people have died in the unrest.
Although violence has flared over the issue for years, drought-like conditions have lingered in Karnataka even as the country overall experienced a normal monsoon season.
Karnataka's reservoirs were 30 percent short of normal levels, while Tamil Nadu's were down 49 percent, according to a recent analysis from the data portal IndiaSpend. Parts of India have suffered successive droughts in recent years that has caused havoc with food supplies and driven more desperate farmers to suicide.
Karnataka officials said last month that the paucity of water has reached crisis levels — and that if more rainfall doesn't come soon, they may run short of drinking water in the coming months. In Bangalore, the groundwater supply has been dwindling due to new construction and increased demand, meaning that the state is relying on river water from the Cauvery now more than ever.
K.S. Puttannaiah, a senior leader with the Karnataka Farmers Association, said that the farmers do not have water for irrigation and that they are unable to harvest their rice crop, losing nearly $600 million in agricultural production.
"We do not have water ourselves. How do we give water to Tamil Nadu? If there is no rainfall, what can we do?" he said.
Climate change experts say that India is one of the most vulnerable countries in the world to climate change. Rainfall is expected to increase with greater variability, which could mean more droughts and floods.
With rising temperatures comes an increased risk of violence, experts say.
A 2013 study by scholars at Princeton University and the University of California at Berkeley, published in the journal Science, looked at 60 studies on climate change and found “strong causal evidence” linking climate events to human conflict across the world.
For each standard deviation in change in climate toward warmer temperatures or extreme rainfall, the authors showed, the frequency of interpersonal violence rose 4 percent and intergroup conflict rose 14 percent.
Human conflict could become a critical effect of climate change if global temperatures continue to rise as forecast, the study found.
Swati Gupta contributed to this report.