The production capacity at Wazirabad, Chandrawal and Okhla water treatment plants has dipped further as the Yamuna has "almost dried up", compounding drinking water problems in several areas in Delhi, officials said on Monday.

An official of the Delhi Jal Board (DJB) said water supply from these plants has reduced by up to 40 percent.

"The Yamuna has almost dried up. The water level in the Wazirabad pond has dipped to 669.40 feet, the lowest this year so far. Consequently, the production capacity at Wazirabad, Chandrawal and Okhla water treatment plants has further dropped to 60-70 percent," the official said.

The level in the Wazirabad pond stood at 670.40 feet on Saturday against the normal level of 674.50 feet.

The pond level had dropped to 667 feet on July 11 last year, prompting the DJB to move the Supreme Court seeking directions to Haryana to release additional water in the Yamuna.

The DJB has thrice written to the Haryana Irrigation Department in this connection in a fortnight -- on May 12, May 3 and April 30.

Haryana supplies a total of 610 million gallons of water a day to Delhi through two canals -- CLC and DSB -- and the Yamuna.

The CLC and the DSB are supplied water from Hathni Kund via Munak canal and the Bhakra Beas Management Board. Besides, Delhi receives 253 MGD from Uttar Pradesh through the Upper Ganga Canal, and 90 MGD is drawn from ranney wells and tube wells installed across the city.

The Chandrawal, Wazirabad and Okhla WTPs have a capacity of 90 MGD, 135 MGD and 20 MGD, respectively.

A reduction of 40 percent means a shortage of 98 MGD of water.

The plants supply drinking water to northeast Delhi, west Delhi, north Delhi, central Delhi, south Delhi, including Delhi Cantonment, and New Delhi Municipal Council areas.

Delhi requires around 1,200 MGD of water, while the DJB supplies around 950 MGD.

The government has targeted increasing the water supply to 1,180 MGD by June 2023.

"We are taking all measures necessary to meet the demand but the situation is worsening by the day due to the intense heat and Haryana releasing less water in the river," another official said on condition of anonymity.

The utility has advised people to store sufficient quantities of water in advance and issued helpline numbers to put in a request for water tankers.