Absence of infrastructure to drain out a meagre half a metre of rainfall led to mayhem
Hussain Sagar lake in Hyderabad. Photo: Wikimedia Commons The City of Pearls is a misnomer — Hyderabad does not produce pearls. Its earlier rulers, the Nizams, brought pearls from across the world, added value and made the city a pearl-trading centre. But those are not the real pearls that we should be talking about.
The rulers also connected several lakes, as in a pearl necklace, to protect the city from floods. These lakes served as a source for drinking water and irrigation too. In a necklace, when most of the beads are removed, its beauty is lost. Similarly, the destruction of Hyderabad’s lakes exposed the city to floods.
Why did Hyderabad flood?
The flooding of Hyderabad in 2020 has little to do with rains and more to do with the absence of lakes, disregard for ecological norms and conversion of the remaining lakes to sewage receptacles.
Urban floods present the same story, be it Kochi, Bengaluru, Gurugram, Bhubaneswar or any other city although the reasons are not the same. Urban planning and smart city concepts woefully fail to acknowledge climate-change impacts in the form of short-duration, high-intensity storm events for draining out stormwater safely to a flowing drainage course.
The last three decades of Hyderabad’s economic growth have been possible only through the creation of housing colonies funded by the private investment of the middle class. The faith and optimism that guaranteed security and protection, turned into deception, leaving several residents wondering the worth of such risks.
Hyderabad historically had small and large water bodies networked in a cascading fashion to convey all stormwater safely into the Musi river. The topology of the city generates a massive flow for a short duration and the chain of lakes provide the buffer to reduce its destructive capacity.
The garland of lakes working in harmony ensured the safe and swift conveyance of water between different points until it entered the river. The network of connected lakes provided hydrological efficiency in flood routing. Unfortunately, the remaining re-engineered lakes are stand-alone units that lack hydrologic as well as ecological functions.
Water bodies occupying less than 10 hectares and their drains were considered as irrelevant and more than 10,000 hectares of land was made available for development.
A flooded street in Hyderabad. Photo: Jamaat-e-Islami Hind #Hyderabad @JIHHyderabad / Twitter
It is precisely on these reclaimed small water bodies and drains that nature came back with a vengeance to trigger short-term flooding and extended waterlogging.
The gullible middle class who have been lured and cheated into occupying these areas for housing, have lost out in the bargain, some of whom will never be able to recover from this loss.
Mostly, documents, appliances and vehicles have been lost, that are not covered by insurance. Informal settlements of the economically weaker sections servicing these households have also been affected and now exposed to viral outbreaks.
Short duration, high-intensity storms will continue to return cyclically, primarily due to climate change impacts. These will acquire menacing proportions in the coming years, thus risking deaths and destruction.
The Hyderabad floods displayed clear socio-economic segregation, with the least-affected areas held by the wealthy and powerful. At the same time, the aspirational middle class and the economically weaker sections were pushed into vulnerable zones. Such zonations are bad for future investments for housing and commerce.
What can be done?
Recovery plans need to move away from engineering solutions while being ecologically sensitive, democratic, people-centred and transparent.
As the first step in this process of transparency, a vulnerability assessment index needs to be estimated for the different clusters.
Physical location, economic activities in the neighbourhood, natural resource base and the historical land-use should form part of the matrix. The proposed mitigation measures need to guarantee risk coverage.
The magnitude of risk transfer that is assured should be made transparent and stand the test of insurance compliance. Only such a strategy can help in ensuring accountability and more importantly make communities responsible for upkeep and protection of all investments. The residents need to have a clear understanding of the extent of vulnerability before making any investment.
A systematic audit on the performance all flood management engineering structures needs to be carried out.
In most situations, new designs became the root cause of the problem. Critical failures have been seen because of combined sewer and stormwater drain. Underground, small diameter pipes choked with plastics acted as an obstacle to the gushing rainwater, leading to destructive overland flow and waterlogging.
The scope for disconnecting the stormwater system from the combined sewer and replacing it through open channels with grass ways is an option for vulnerable areas. Such a design automatically eliminates the impervious layer while providing flood banks as well as enhancing green spaces.
Visionary thinking, respect for the environment and integration of engineering aspects without themselves turning into a problem is crucial aspect of solution design.
Urban flooding cannot be managed in the absence of small water bodies and open flow channels. Re-engineering of the existing development plans is an urgent requirement. A partnership between local bodies and housing colonies should be an integral part of the solution.
The major stakeholders are the residents and a sustainable protection plan needs to have a bottoms-up approach with every home in sync with the local climate and environment.
The concept of end-of-pipe sewer lines needs to be reworked, with revival of small water bodies for each housing cluster that will also double up as primary water treatment sinks. The network of immediate water treatment sinks connected through open channels offers a routing mechanism of flood flows.
Constructed wetlands at critical locations will help to buffer the floods during storms and in normal times treat the water by removing nutrients as well as serve as oxidation ponds.
Reluctance towards flood preparedness and mitigation could be fatalistic attitudes for both, the residents and government.
Dependence of communities on too much government support absolves them of collective responsibility in being part of the solution. It is time to equip communities to build resilience to anticipate, prepare, cope, resist and recover from the impact of any form of eventuality natural or human-made.
How long will it take to ensure protection from urban floods will depend upon owning and undoing the massive blunders that have led to this situation.
KAS Mani is a water resources consultant with over four decades of experience largely with UN and other funding agencies
Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth
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