New Warnings From Hyderabad

Context:  Rising urban floods points towards the problems of urban development, conservation of water bodies, climate change, flood warning systems and policy response to climate change.

Reason Behind Rising Urban Flood 

• Climate change: Link between carbon emissions, warming seas and transport of moisture from the Arabian Sea to the Central Indian region has been established.

• Warming of North Arabian (due to transport of pollutants from land) leads to a surge of moisture supply, which leads to extreme rain events.
• Rain events and urban flooding have tripled in Central India between 1950 and 2015.

• Insufficient and inadequate urban drainage system: lack of space for the rainwater to flow into drains, rivers and other channels.
• Wrong urban development policies and land-use patterns: as a result of short-sighted and politicised urban planning like

•  Conversion of natural soaking mechanisms (like lakes) into infrastructure (like roads, flyovers and buildings).
• Illegal encroachment of floodplains of rivers and rivulets.
• Shrinking of open, green spaces disregards natural drainage flow. 
• More focus on relief measures than on preventive measures.
• Lack of linkages within the administrative machinery: has rendered most State climate actions plan as ineffective.

Case Study: Flood Control during the period of Nizams

• Mokshagundam Visvesvaraya, a leading engineering expert of British India and later to be Diwan of the Mysore state, was commissioned by Mir Mahbub Ali Khan, the sixth Nizam, to advise him on scientific management of floods. 

• His recommendations were threefold:

• Construction of two large reservoirs for storing excess waters of the Musi and its branch Isi (Osman Sagar and Himayat Sagar).
• The underground drainage system and separate stormwater drains
• Raising the embankments of the Musi and construction of riverfront with new boulevards along the river in the city.

• Took care of a future increase in the population of the city up to one million and even provided for the introduction of an electric tram service in future, as it was being rolled out in many large cities in British India.

Way Forward

• Adaptation measures: must be adopted after studying and analysing the trend of rising extreme weather event, and should include the following: 

• Modelling drainage systems, stormwater management systems and use of localised data for the prevention and management of floods. 
• Urban flood forecasting systems with real-time flood-monitoring
• Satellite imagery, weather forecasts, ground information through sensors must be used in an integrated manner. 
• Prioritised revival and conservation of water bodies with an understanding of their inter-connectivity.

• Decentralised Climate Action Plans: Climate action programmes for individual cities must be prepared for initiating a focused and coordinated flood action plan.