USING RAINWATER AS A SUSTAINABLE RESOURCE IN THE CONTEXT OF INDIAN CITIES

In India, city authorities supply water for domestic use. Residents make up the deficiencies by private measures in exploiting the available groundwater in the city and region. At the same time, rainwater that falls over city neighborhoods is allowed to drain away without a thought to using it intelligently. This has lead to problems like falling groundwater tables, water stress in the city region, urban flooding and poor groundwater recharge due to an attitude of drainage rather than recharge. This paper builds a picture of the nature of Indian rainfall i.e. its many precipitation patterns over the geographical spread of India, its variability in the short term due to the nature of the monsoon and in the long term brought about by global warming. Using this picture it evaluates to what extent rain over neighborhoods could form a sustainable source of local supply. The paper also examines the question of neighborhood strategies for storage, based on volume of water required, the hydro-geological conditions and the current level of ground water conditions. It demonstrates how the land-man ratio impacts these strategies and point towards sustainable residential densities if rainwater were to be considered as a local resource. At this point in time the National Building Code of India - 2005 and The Urban Development Plan Formulation and Implementation Guidelines- 2001 form the recommendatory codes used as performance guidelines for each city to evolve its master plan and development controls for urban development. Therefore if utilizing rainwater were to become a significant planning parameter for sustainable neighborhoods this paper would point towards the required shift in the operating national codes and planning norms.