Rejuvenation of nag river corridor with blue green interventions: a case of nag river, Nagpur

Abstract

All the necessities of life that a man encompasses with are subjected to accessibility and availability of water. It is evident from past history of settlements that most of the cities are founded near river. Rivers act as a life line to cities providing essential needs of the people. The practices of mankind, particularly urbanization have covered with built structure on the natural water channels, resulting in disturbances in urban water cycle and have marginalized waterscapes. Further, industrialization and domestic waste in polluting rivers resulting in deterioration of river water quality and emergence of foul smelling rivers. India is facing river related problem which were tackled by developed countries after industrial revolution. In Indian cities the concern of their water streams, stream corridors and watersheds should be developed in order to have balance between urban and natural environment to achieve sustainability. Traditional model of infrastructure intervention are gradually showing their inability to cope with the environmental pressures and growing demands, on the other side it is clear to rethink urban development pattern as catalyst of value and prosperity. In response to this urgency Blue Green Infrastructure provides an alternative way to conceive next generation infrastructure and built form of the city though robust, synergistic and multifunctional water management. The integration of such systems can recalibrate the present infrastructure by redefining spatial strategies to retrofit soft technology in the existing urban fabric which is capable to metabolize flow and their management cost for greater climate resilience and livability. The aim of the study is to find the impact of urbanization on the river (Nag River flowing through Nagpur). The study focuses on identification of different sources of pollution and their causes on urban environment. The physical and environmental factors of river and systems of drains, sewerage system etc. that are polluting the river and are turning it into a waste water drain. The river water is explored in terms of qualitative and quantitative terms and different types of benefits that can be generated by it, the present infrastructure and its gaps are identified. Through this analysis target areas are identified and Action Area based proposals with the incorporation of Blue Green Infrastructure in the present system of city are proposed and help Rejuvenation of the Nag River and upgrade the urban living condition in a Natural Environment Based Solution to attain sustainability. To rejuvenate the river the Green infrastructure elements are used in local and neighborhood scale to increase the ground water and surface water table and recharging through possible building and site level interventions like roof top gardening, rain water harvesting, green walls, raingardens, swales, green corridor, waterways etc. to increase the water quantity and quality. Also to stop direct disposal of sewer in the river through the present sewerage system, the proposal of interception and diversion sewerage system is to be incorporated with decentralized STP network to inlet safe and desired quality of water in the Nag River. The proposed BGI will be designed on the basis of urban landscape network intervening different spatial and temporal scales. The model systematically and spatially defines the role and scope of urban landscape patches and corridors which integrate natural areas with built form and have sustainable urban development approach.