After Phase-1 Drainage Woes, MahaMetro Bets On Smarter Rainwater Design in Phase-2 | Nagpur News

Nagpur: MahaMetro’s rainwater harvesting system has come under scrutiny following complaints of clogged recharge points, leakages from viaduct drainage pipes and water spilling onto roads during heavy rain. Sources said the agency has drawn lessons from past shortcomings and redesigned the rainwater harvesting mechanism for Metro Phase-2 to address recurring problems reported along stretches of the Phase-1 corridor. Officials claim the new system marks a significant departure from the earlier model. Instead of the exposed drainage pipes seen at several locations on the existing network, rainwater will be routed through PVC pipelines concealed within Metro piers before being discharged into specially designed recharge zones beneath median flower beds. The recharge structures have also been redesigned. The earlier system relied on relatively small 1×1-metre pits and recharge bores 6-7 metres deep. The new network will feature three precast collection chambers of 1,200mm diameter, larger connecting pipelines, filter media systems and cleaning taps aimed at preventing silt accumulation and blockages. Recharge depths will be determined according to local geotechnical conditions rather than a uniform standard. According to sources, rainwater flowing from viaducts along the Aqua Line is designed to drain into recharge structures located in the central median. While the system is intended to recharge groundwater and reduce surface runoff, repeated clogging of collection points with mud, silt and debris has often led to waterlogging and stagnant pools on roads. Officials from NMC’s hot-mix department said the problem extends beyond temporary inconvenience. Persistent leakages accelerate road deterioration, contribute to pothole formation and increase maintenance costs. Residents and civic authorities are now questioning whether the Phase-2 corridors will overcome the drainage deficiencies witnessed on the existing network or repeat the same shortcomings despite the revised design.