Water woes | Namma Metro calls tender to implement rainwater harvesting for Purple and Green lines in Bengaluru

BMRCL calls tender for rainwater harvesting projects to recharge groundwater along Bengaluru metro lines, addressing severe water crisis.

Amidst a severe water crises, Bangalore Metro Rail Corporation Limited (BMRCL) has called a tender to implement Rain Water Harvesting (RWH) projects in Bengaluru to ensure that the rain falling on Namma Metro’s elevated concrete tracks is used to recharge the groundwater table.

BMRCL officials said that the tender has been called to dig RWH pits below the viaduct along the metro alignment of Line 1 (Purple Line) and Line 2 (Green Line), and stations.

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At present, the metro spans 73.75 km and includes 65 stations in Bengaluru, of which 65.01 km is an elevated structure with the potential to harvest rain water. However, rainwater harvesting systems have been implemented only in select stations.

“We are planning to initiate rainwater harvesting at an estimated cost of ₹65 lakh. The potential for rainwater harvesting to replenish the groundwater table along metro lines is significant, which is why we have called a tender to initiate the process now,” a BMRCL official said.

At present, rainwater harvesting for groundwater recharge is solely accessible along the metro line connecting M.G. Road and Baiyappanahalli metro stations (Reach 1). The BMRCL has built 3,000 litre-capacity underground tanks on both sides of every second metro pillar between M.G. Road and Baiyyappanahalli metro stations. In-built pipes carry rainwater from the duct to the tanks on the medians.

In June-July 2023, a survey conducted by the NGO ActionAid India revealed the absence of rainwater harvesting facilities along the Green and Purple lines of BMRCL.