Senior advocate AM Singhvi, appearing for DJB, said that water level has fallen in the national capital.
The Supreme Court Thursday directed governments of Punjab, Haryana and others to maintain status quo on supply of Yamuna water to Delhi till March 26.
The top court was hearing an application filed by Delhi Jal Board (DJB) which has sought directions to the Haryana government to cease the discharge of untreated pollutants into the Yamuna and release sufficient water to the national capital.
A bench headed by Chief Justice SA Bobde issued notices to Haryana, Punjab and Bhakra Beas Management Board (BBMB) and asked them to file their responses on the application by Friday.
Senior advocate AM Singhvi, appearing for DJB, said that water level has fallen in the national capital.
Senior lawyer Shyam Divan, appearing for Haryana, said that full level of water supply has been made.
Senior advocate Vikas Singh, who also appeared in the matter, said that a court commissioner should be appointed to verify the water level.
Divan said no application has been filed for the appointment of court commissioner in the matter.
"This is about the fundamental right to water. We will not go into technical issue whether court commissioner can be appointed only after the application. If the need arises, we can appoint it," said the bench, also comprising Justices A S Bopanna and V Ramasubramanian.
Advocate Gautam Narayan, who also appeared for DJB, argued that Haryana says they are doing some repair work.
Singhvi said that canal repair works should not be done in the months of March and April when the water demand is at its peak.
He said DJB had written several letters last month to Haryana on the issue but has not received any reply.
"We have two crore urban population. We have Luteyns Delhi, we have Aam Aadmis. This will cut down 25 per cent water supply," he said.
The bench, while issuing notice on the application, said it would hear the matter on Friday.
In its fresh application filed in the top court, the DJB has said that direction be issued to Haryana government to release the water to avert a potential severe crisis in the national capital.
It has claimed that Haryana government has reduced the supply of raw water to Delhi, resulting in shortage of water supply in the national capital.
DJB chairman Raghav Chadha said in a statement earlier this month that regular fall in the level of the Yamuna, especially during summers, along with the discharge of pollutants that cause rise in ammonia levels, is a matter of grave concern.
The DJB had said that Delhi is facing a potential severe water crisis due to high ammonia levels in the Yamuna and the continuously depleting water level at Wazirabad barrage, which supplies drinking water to the Wazirabad, Okhla and Chandrawal water treatment plants.
Raw water is sourced from the Yamuna and is drawn at Wazirabad barrage, it had said, adding that the quantity and quality of raw water at Wazirabad Barrage is dependent on the release of water by the Haryana government.
Haryana supplies water to Delhi through the Carrier-Lined Channel (CLC), Delhi Sub-Branch (DSB) and the Yamuna. The CLC and DSB supply water from Hathni Kund via Munak canal and Bhakra Beas Management Board.
At present, Delhi receives 479 million gallons water a day (MGD) against 609 MGD from Haryana. Besides, Delhi draws 90 MGD groundwater and receives 250 MGD from the Upper Ganga Canal.
The normal level of the Yamuna near Wazirabad Pond should be 674.50 feet but it has dropped to 670.90 feet.
The fall in the water level at Wazirabad pond has affected water production at Wazirabad, Okhla and Chandrawal water treatment plants which supply drinking water to central, north, west and south Delhi.
As per the DJB, currently, Haryana through CLC canal is supplying only 549.16 cusecs against 683 cusecs and Delhi Sub-Branch canal is supplying 306.63 cusecs against 330 cusecs.
The treatment capacity at Wazirabad and Chandrawal water treatment plants has dipped by 30 per cent. The same has reduced by 15 per cent at Okhla WTP, he had said.
On January 19, the top court had sought a report from a committee, set up by the National Green Tribunal (NGT), regarding the recommendations made by the panel for improving the water quality of Yamuna river and the extent to which authorities have implemented them.
The NGT had on July 26, 2018 constituted the monitoring committee comprising its former expert member BS Sajwan and former Delhi chief secretary Shailaja Chandra on the cleaning of Yamuna river and had directed it to submit an action plan in this regard.
The top court had on January 13 said that pollution-free water is a fundamental right which a welfare state is "bound to ensure", and issued notices to the Centre, CPCB and five states including Delhi and Haryana on the issue.
The top court, while appointing senior advocate Meenakshi Arora as amicus curiae, had directed its registry to register the suo motu case as ''Remediation of polluted rivers'', said it would first take up the issue of contamination of the Yamuna river.