The southwest monsoon has once again proven disastrous for many states in India. A series of flash flood events like the recent one in Uttarakhand have wreaked devastation in several areas with the visuals of complete extermination of habitations near the water channels portraying the alarmity of the situation.
The calamitous occurences, though, are not limited to this year. Numerous major events in the past two decades illustrate how encroachments on floodplains have worsened the impact of flood disasters. Most of the floods highlight the consequences of rapid urbanisation, encroachments on waterbodies and lands adjacent to riverbanks, and the disappearance of wetlands. These factors disrupted natural drainage systems and exacerbated the crisis.
Why flood-Induced disasters matter
India is the second-most flood-impacted nation in the world, following Bangladesh, and accounts for one-fifth of the global death toll from floods. According to the National Disaster Management Authority, out of India's total land area of 340 million hectares (mha), more than 40 mha are classified as flood-prone. Flash floods are among the most devastating natural hazards, claiming over 5,000 lives annually while causing considerable social, economic, and environmental damage. Notably, flash floods have the highest mortality rate (the ratio of deaths to the number of affected individuals) compared to riverine and coastal flooding.
To regulate development in flood-prone areas and mitigate associated risks, the Central Water Commission (CWC), part of the Ministry of Jal Shakti, has created the first technical framework guidelines, 'Technical Guidelines on Floodplain Zoning 2025.' These guidelines encourage all states to adopt non-structural measures to reduce the impact of flood-related disasters.
New guidelines
The guidelines categorise floodplains into three zones, each with specific restrictions on activities: the Protected Zone, the Regulatory Zone, and the Warning Zone.
Protected Zones (both rural and urban areas) are subject to flooding once every five years. Regulatory Zones experience flooding once in the 5-25 year range, while flooding happens in Warning Zones (only in urban areas) once in 25-100 years.
In the Protected Zone, the guidelines prohibit any permanent structural activities, except for public purposes such as civil and railway infrastructure. It includes prohibition of any construction that disturbs the natural course of the river channel, except for essential services and infrastructure (ESI). ESI includes gas and petroleum pipelines, power lines, bridges, barrages, green riverfronts, etc. It also prohibits dumping solid waste, creating landfills, storing hazardous materials, or establishing large-scale commercial or industrial facilities.
However, it supports sustainable activities such as traditional organic farming, fisheries, animal grazing, eco-friendly tourism, and the installation of hand pumps for drinking water, parks and playgrounds.
In the Regulatory Zone, residential settlements, critical defence installations, and basement construction are prohibited. However, it permits public institutions, government offices, universities, educational institutions without residential facilities, public libraries, sewage treatment plants, and community halls.
In the Warning Zone, hazardous waste-producing chemical industries and nuclear plants are prohibited but public utilities such as hospitals, power installations, water supply systems, telephone exchanges, railway stations, airports, and commercial centres are allowed.
"Municipal bodies in the country tend to utilise floodplain land for development purposes, including residential areas and commercial structures, which significantly increases disaster risk," said D P Mathuria, Chief Engineer of the CWC, who oversees the framework's preparation.
Previous bid to conserve floodplains
The National Green Tribunal in 2017 directed the demarcation of floodplains for the Ganga, covering the area from Haridwar in Uttarakhand to Unnao in Uttar Pradesh. Additionally, in efforts to restore the Yamuna, the Tribunal instructed the state to adopt a precautionary approach, mandating various steps to be taken by authorities. These steps include issuing prohibitory orders against dumping or throwing any kind of waste into the drains leading to the Yamuna, as this significantly harms the environment.
In 1975, the CWC circulated a model draft bill for floodplain zoning to all states. It aimed to zone the floodplain of a river based on flood frequencies and define acceptable types of land use within them. States such as Manipur, Rajasthan, Uttarakhand, the erstwhile J&K, and Arunachal Pradesh enacted related legislation. However, the delineation and demarcation of floodplains have yet to be fully implemented.
Under the National Mission for Clean Ganga programme, the government regularly issues directives to all states in the Ganga basin concerning the demarcation, delineation, and notification of river floodplains, as well as the removal of encroachments from the riverbed or floodplain of the Ganga and its tributaries.