In recent times, Kerala is once again facing a situation reminiscent of the 2018 floods, triggered by intense monsoon rains. Additional pressure from a potential low-pressure system forming over the Bay of Bengal within the next few days threatens to exacerbate the situation.
Recalling the 2018 Kerala Flood Trauma
Kerala experienced its worst flooding since 1924 in August 2018, following torrential rainfall. The dams filled to their brim, and an excess of stored water necessitated opening the dam gates. Approximately 35 out of 50 larger dams were forced to flood already inundated areas downstream. The holding capacity of the dams and adjoining rivers had been compromised due to silt deposition, which resulted in the overflow of embankments and levees. Factors such as encroachment reducing the built-in area of dams, rampant felling of trees, clearing of forests in Western Ghats, and sand mining also contributed to the flood.
Floods: An Overview
Floods occur when there is an overflow of water onto land that is usually dry. This can be a consequence of heavy rains, ocean waves coming ashore, quick snow melts, or when dams or levees collapse. Damaging flooding can happen even with a few inches of water, but may also cover a house up to the rooftop. Floods can occur rapidly or over a prolonged period, lasting days, weeks, or longer, making them the most widespread of all weather-related natural disasters. The most destructive are flash floods due to their speed combined with the harmful power of a flood.
Reasons Behind frequent Urban Flooding
Unplanned development, encroachments in riparian zones, failure of flood control structures, inefficient reservoir operations, poor drainage infrastructure, deforestation, land use change, and sedimentation in riverbeds exacerbate floods. Unregulated urbanization has led to frequent flooding in towns and cities due to encroachment of waterways and wetlands, insufficient drain capacity, and poor maintenance of drainage infrastructure. On top of it, poor waste management compounds the problem by clogging drains, canals, and lakes.
Disregarding Pre-Disaster Planning
The central focus of flood management has been primarily post-flood recovery and relief, neglecting pre-disaster planning. Many reservoirs and hydro-electric plants lack sufficient gauging stations for measuring flood levels—the principal element for predicting and forecasting floods.
Ignoring Gadgil Committee Recommendations
In 2011, the Madhav Gadgil committee recommended declaring approximately 130,000 sq. km area as an environmentally sensitive zone across Gujarat, Karnataka, Kerala, Maharashtra, and Tamil Nadu. However, these recommendations were not accepted, particularly by Kerala, due to opposition against proposed bans on mining, construction activity restrictions, and embargoes on hydroelectricity projects. This negligence is now evident in the form of recurrent floods and landslides.
The Way Forward
Improved coordination between forecasting agencies and reservoir management authorities could ensure timely spillway openings and creating necessary holding capacity in the reservoirs to absorb excess rainfall. A comprehensive flood management plan needs to be developed, which includes all aspects of urban growth, beginning with affordable housing. This would significantly contribute towards adapting to future climate change. Countries like Japan, frequently experiencing earthquakes and tsunamis, serve as perfect examples of how planned urbanization can resist disasters. Policies and laws should clearly outline watershed management and emergency drainage plans. It is essential to consider natural boundaries such as watersheds over governance boundaries like electoral wards when designing a drainage plan.