Feasibility of Rooftop Rain Water Harvesting at Grey Iron Foundry, Jabalpur, Madhya Pradesh, India

As a supply-side option to manage the depleting groundwater resources in India, the Central Government has made it mandatory to install rain water harvesting system in any building with a plot size of 100 m² (MoUD (Ministry of Urban Development), Model Building Bye-Laws, Town and Country Organization, Government of India, 2016). An attempt has been made in this contribution to carry out feasibility study for rooftop rain water harvesting at the Grey Iron Foundry (GIF), Jabalpur, Madhya Pradesh, India. Since the post-monsoon groundwater levels in the area are in the order of about 2–3 m, scope for gravity recharge is limited and there is not much natural subsurface space available for storage of the harvested rain water. However, underground and on-the-ground artificial tanks can be constructed to store the water for further use. The three buildings examined have a combined roof area of 21,927 m² with a rain water availability of 21,784 m³ giving a recharge potential of about one m³ of rain water for every m² of roof area. Groundwater in the area contains high amount of fluoride and cannot be used for drinking purposes without adequate treatment. It is also not advisable even to drink the harvested rain water since it is slightly acidic in nature. It can, however, be used for other useful purposes, such as for gardening, horticulture and industrial cooling. It is estimated that about 85% of the cooling water requirements of the GIF can be met by harvested rain water. India consists of innumerable buildings across the country, and this foundry serves as a case study to harvest rain water in small scale industrial complexes even if post-monsoon groundwater levels are shallower to save the country from an impending danger.