The Composite Water Management Index, released by the Niti Aayog on Thursday, begins with the line: "India is suffering from the worst crisis in its history and millions of lives and livelihoods are under threat."
The report says that 600 million Indians face high to extreme water stress, and two lakh people die every year because they cannot access safe water.
"The crisis is only going to get worse," the report says.
"By 2030, the country's water demand is projected to be twice the available supply, implying severe water scarcity for hundreds of millions of people and an eventual ~6% loss in the country's GDP," it says.
Water Index scores, which have been put together on the basis of 28 indicators including ground water, restoration of water bodies, irrigation, and drinking water, are below 50 percent in most states.
The best performing states are Gujarat, Madhya Pradesh, Andhra Pradesh, Tripura and Meghalaya, according to the report, with scores ranging from 76 to 56.
The worst performing states are Uttar Pradesh, Haryana, Jharkhand, Uttarakhand and Meghalaya, according to the report, with scores ranging from 38 to 26.
Fifteen out of 24 state are low performers, with scores less than 50 percent, concentrated across the populous agricultural belts of North and East India, and among the North-Eastern and Himalayan states.
Low performers include Uttar Pradesh, Bihar, Rajasthan, and Haryana, which are some of India's most populous states, home to over 600 million people.
These states also account for 20-30% of India's agricultural output.
Read the full report here.