The metro railway project has brought in its train a problem on another front: management of water.

As digging proceeds on a daily basis, gallons of sub-soil water have to be extracted and disposed of. The Delhi Metro Rail Corporation (dmrc) has made elaborate arrangements not to waste the water by letting it flow into Yamuna river.

Given the depleting groundwater levels in Delhi, the dmrc has decided to use part of the water extracted in northern Delhi to replenish lakes in the nearby Kamala Nehru Ridge. The rest, it claims, goes to the Chandrawal Water Works of the Delhi Jal Board (djb).

The segment of the metro between Delhi University (North Campus) and the Inter-State Bus Terminus (isbt), say experts, is the most problematic