Rainwater Harvesting for Metro Rail Projects in India – Scope for Efficiency Improvement

Abstract

Rainwater Harvesting (RWH), although an ancient technique of artificial recharge to groundwater and reuse of stored rainwater, has been improved with the developing technology. RWH systems have many benefits in rural as well as in urban areas of arid and semi-arid regions. Almost all metro cities of India are facing problems of water logging and flooding even after a short heavy rainfall. In metro cities RWH could be helpful for artificially recharging groundwater in depleted water level areas; reduction of flood risk in urban areas; assured source for an effective alternative water supply solution and use of harvested water during water scarcity period. Nevertheless, most of the studies in literature focused on the potential of RWH for buildings, institutional areas for reducing water consumption, whereas few examples were examined for their efficient use. Almost all big cities in India are planning metro rails which have huge potential for RWH with its elevated stations, viaduct (elevated corridor) and depot areas. This work aimed to investigate and realize the RWH potential especially for metro rails which are in the implementation stage for different cities in India. This paper also highlighted the legislations of RWH of different states where metro rails were implemented. It also emphasized on the root cause of inefficiency of the RWH system and how to increase the efficiency.