The submission was made before a bench headed by NGT Chairperson Justice Swatanter Kumar which on October 25, last year, had asked DMRC why rain water harvesting systems (RWHS) cannot be installed in several of its stations.
The DMRC assured the tribunal that it is "planning to physically execute the work at the 17 stations progressively by March 2015".
Without a completion certificate, "no person is permitted to occupy or can permit to occupy any such building", the two corporations have said in their affidavits.
During the hearing, Delhi Pollution Control Committee sought more time to complete their inspection of government departments, hospitals and residential buildings to see if they have installed RWHS and whether the same are functional.
The tribunal was hearing a plea seeking installation of RWHS in metro stations, government departments, hospitals and residential buildings in the national capital.