A water crisis in India's capital will take up to two weeks to fix, authorities warned on Tuesday, as taps ran dry, days after protesters sabotaged a crucial waterway to press a demand for better treatment for their caste.

The Jat caste called off their protests on Monday after the government in the northern state of Haryana accepted their demands following days of riots, arson and looting that saw thousands of troops deployed.

But New Delhi's water board was still racing to restore full supplies to the city of 17 million people that relies heavily on a canal running through Haryana, which encircles the city on all but its east side.

Water trucks fanned out across the teeming, landlocked city, where infrastructure struggles at the best of times, but it was not clear just how many people were still affected, although many households were without regular water four days after the canal was badly damaged.

Senior water board official Neeraj Semwal said just four of the city's nine water treatment plants were operating, forcing rationing of supplies to many areas.

"We are hoping to restore partial services in the next two to three days and 100 percent supply within next 15 days," Semwal said.

"North, west and south Delhi districts were severely affected by the water shortage with thousands of households not getting regular water supplies."

Delhi water minister Kapil Mishra tweeted that the crisis was "not over yet" and urged residents to conserve water.

India sent troops to secure the canal after protesters demanding a quota for their Jat caste in public service jobs and higher education seized it on Saturday and diverted the water flow away from the capital.

Although schools and many businesses reopened on Tuesday as supplies were partially restored, many were still suffering after the water board said it had been forced to limit supplies.