Urban floods are the inundation of the urban areas which are characterized by greater degree of pavement and less open spaces creating huge runoff overwhelming the drainage system. There have been increasing intensity of urban flooding in the recent times which is largely attributed to bad planning and climate change.

Reasons for urban floods in India

• Overflowing rivers: due to heavy rainfall, silting of river channel and encroachment of floodplains. 
• Rising Sea Level: It has affected the flow of underground drains in coastal cities during high tides, especially in Mumbai where a lot of city is built on reclaimed land.
• Old Drainage system: which is unsuited for the overgrown city capacity and frequently gets clogged, like in old cities of Hyderabad, Mumbai & rapidly growing urban centres of Gurugram & Delhi.
• Disappearing wetlands: In cities like Delhi, Hyderabad, Bengaluru, Chennai etc. thousands of ponds and lakes have been encroached. In tier 2 and 3 towns too similar trend is seen.
• Bad Reservoir Management: due to which during heavy rainfall dams have to release water for example in 2014 Srinagar floods, in 2018 Chennai flood Chembarambakkam Tank released water, in 2020 Hyderabad floods Himayatsagar reservoir on Musi river released water. Only 7% of Indian dams have emergency action plans.
• Inefficient Data and Flood prediction systems: There is a lack of data sharing between reservoirs and the meteorological department.
• Rigid pavement and low water permeability: Our cities are becoming increasingly impervious to water, not just because of increasing built up but also because of the nature of materials used.
• Climate Change: It has increased the extreme weather events and incidence of flash floods all around the world.
• Sedimentation of streams and canals: For example in 2014 Srinagar floods it was found that emergency flood channel has disappeared due to sedimentation and encroachment over the several decades.

Mechanisms in place for preparedness to reduce such events

•  Warning and Information sharing system between national, state & local bodies through WRIS(water resource information system) which shares the water level data of the reservoirs in real time.
• National Hydrology Project: A central scheme under which the Hydro-meteorological data will be stored and analyzed in real time basis and can be seamlessly accessed by any user at State, District & Village level.
•  IFLOWS: for providing early warning for urban flooding, especially during high rainfall events and cyclones. It will be possible to have an estimate of the flood inundation three days in advance, along with immediate weather updates. It is functional currently in Chennai & Mumbai.
• Dam rehabilitation and Improvement project (DRIP) to improve safety and operational performance
• MAUSAM app - Weather forecast and warning to citizens
• National Monsoon commission for dynamic monsoon forecasts             

Other Major Mechanisms that can further improve the system

• Inter-river linkage: Which can help in diverting excess water from one catchment to another.
• Strict implementation of Environment Impact Assessment(EIA).
• Drainage Information system: which can help in establish a systematic procedure for pre-monsoon de-silting, water and solid waste management, flow data analysis for better design and is avialable to all stakeholders
• Policy Mechanism for city level drainage planning: to incentivize rainwater harvesting(property tax rebates and easy home loans), concept of sponge cities, preventing encroachment of wetland and more open spaces.
• Leveraging existing Schemes: such as Smart cities mission, Atal Mission for Rejuvenation & Urban Transformation (AMRUT) and National Heritage City Development & Augmentation Yojana (HRIDAY).             

The rising incidence of urban flooding can be controlled through redesigning the cities and especially its green areas for greater seepage and its drainage system for better evacuation of water. This would require big investment and city level plan exclusive to each area. For this it shall be essential to scale up the efforts under mechanisms like smart city multiple times and decentralizing the planning, management and maintenance, as recommended by Mihir Shah Committee.