Q) Account for the huge flooding of several Indian cities in the recent years and suggest lasting remedial measures for mitigating them.
Why this question?
Important part of GS Paper-III.
Key demand of the Question
Explain what urban floods are, its causes and solutions.
Account – Weigh up to what extent something is true. Persuade the reader of your argument by citing relevant research but also remember to point out any flaws and counter- arguments as well. Conclude by stating clearly how far you are in agreement with the original proposition.
Start by giving a definition of urban floods.
In the first part, explain in detail the causes of urban floods.
In the next part, provide for long lasting solutions for the problem.
Conclude with a way forward.
Urban flooding has wreaked havoc on major Indian cities in the recent past. Last year, Hyderabad saw massive floods due to heavy rains. About five years ago, Chennai saw a massive flood costing much damage and lives; Gurugram over the past few years comes to a complete standstill during the monsoon months, and for Mumbai, the monsoon has become synonymous with flooding and enormous damages.
Causes of Urban Flooding
- Meteorological Factors: Heavy rainfall, cyclonic storms, and thunderstorms.
- Hydrological Factors: Overbank flow channel networks, the occurrence of high tides impeding the drainage in coastal cities.
- Anthropogenic Factors:
- Unplanned Urbanization: Unplanned Urbanization is the key cause of urban flooding. A major concern is blocking of natural drainage pathways through construction activity and encroachment on catchment areas, riverbeds, and lake beds. Pollution of natural urban water bodies and converting them for development purposes has increased the risk of floods. Reduced infiltration due to paving of surfaces which decreases ground absorption and increases the speed and amount of surface flow.
- Storm-water Drainage systems: These were designed for a rainfall intensity of 12-20 mm. Indian urban centres receive much heavier rainfalls and these outdated designs are not relevant now. The old and ill-maintained drainage system is another factor making cities in India vulnerable to flooding.
- Encroachments: Encroachments are also a major problem in many cities and towns. Habitations started growing into towns and cities alongside rivers and watercourses. As a result of this, the flow of water has increased in proportion to the urbanization of the watersheds. The capacity of the natural drains has decreased, resulting in flooding. The number of wetlands has reduced to 123 in 2018 from 644 in 1956.
- Climate Change: Climate change due to various anthropogenic events has led to extreme weather events.
- Poor Solid Waste Management System: Domestic, commercial and industrial waste and dumping of construction debris into the drains also contribute significantly to reducing their capacities. Improper waste management system, clogging of storm-water drains because of silting, accumulation of non-biodegradable wastes and construction debris are major concerns.
- Reducing Seepage: Indian cities are becoming increasingly impervious to water, not just because of increasing built up but also because of the nature of materials used (hard, a non-porous construction material that makes the soil impervious).
- Lax Implementation: Even with provisions of rainwater harvesting, sustainable urban drainage systems, etc, in regulatory mechanisms like the Environmental Impact Assessment (EIA), adoption at user end as well as enforcement agencies remains weak.
- No Community Participation: Flood control measures planned without participation of the affected community are unsustainable as they do not meet the needs of relevant stakeholders.
Steps that need to be taken
- National Disaster Management (NDMA) Guidelines: In 2010, NDMA had issued guidelines on Urban Flood Management in India -to create a National Hydro-meteorological Network for providing early warning, use of Doppler Weather Radars to be expanded to cover all urban areas in the country, an inventory of the existing storm water drainage system to be prepared etc.
- Rain water harvesting and other check measures: on-channel storage of rainwater in storm drains, artificial recharge trenches, retention basins, deepening of ponds and lakes etc.
- Sustainable usage of land: Low-lying areas in cities have to be reserved for parks and other low-impact human activities, restrict encroachments in natural drainage areas; clearance of river beds, proper implementation of Coastal Regulation Zone rules. Planting drought resistant and flood resistant sturdy trees in vulnerable areas also helps.
- Utilising International best practices: Implementing ‘Mobile Walls’ like in Germany, and ‘sponge’ cities in line with cities in China which involves replacing concrete pavements with porous pavements to ensure better filtration.
- Policy making and city planning: Each city should have their Flood mitigation plans strongly embedded within the master plan of the city. There should be prompt, well-coordinated and effective response in case of urban floods to minimize casualties and loss of property and also facilitate early recovery.
- Wetland protection: Urban flooding may increase if wetlands are not protected. Centre for Science and Environment (CSE) has recommended strong laws to protect urban lakes, their catchment and feeder channels.
Floods have become a more common phenomenon in the wake of climate change and unorganised urban development has worsened the situation. India has to learn its lessons from recent floods, in Assam, Bihar, Tamil Nadu, Karnataka and Kerala. Addressing the underlying causes and taking immediate effective corrective measures is the most important need to tackle and overcome the floods and its devastation.