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Flood Plain Zoning

GS1/GS3 Paper 

 Syllabus: Geography/ Disaster Management

 

Source: IE

 Context: Reckless urbanization near riverbeds is a key factor in recent floods in Punjab. Experts from the National Institute of Hydrology emphasize the need for floodplain zoning plans as a long-term solution to mitigate flood losses.

 

What is Flood Plain Zoning?

Floodplain zoning is a land use planning strategy that designates specific areas along rivers and water bodies for various uses based on their susceptibility to flooding.

Aim: The aim of floodplain zoning is to regulate development in these areas to minimize the potential damage and risks associated with floods.

 

Example of floodplain zoning:

The areas along the river are divided into different zones based on the likelihood and severity of flooding:

  • High-Risk Zone (Zone A): This zone is closest to the river and has the highest risk of flooding during heavy rain events.
    • In this zone, only limited and essential structures are allowed, such as flood-resistant community centres, parks, and open spaces. Permanent residential or commercial buildings are prohibited to prevent damage and loss of life.
  • Moderate-Risk Zone (Zone B): This zone is located slightly farther from the river and has a moderate risk of flooding.
    • Here, some residential and commercial development is allowed, but structures must adhere to flood-resistant design standards. Building elevations might be required to keep living spaces above potential flood levels.
  • Low-Risk Zone (Zone C): This zone is situated at a greater distance from the river and has a lower risk of flooding.
    • In this area, most types of development are permitted, including homes, businesses, and recreational facilities. However, structures might still need to meet certain flood-resistant criteria to ensure safety.

 

Different aspects of Flood Plain Zoning:

Aspects 
BenefitWell-maintained flood plains act as natural defences against flooding and recharge groundwater levels.
Identification of flood plains based on topography helps in better land use planning.
It not only reduces the damage caused by floods but also maintains the ecological balance of the floodplain and helps recharge groundwater levels.
Proper zoning can prevent unsuitable constructions and concretization of flood plains.
ChallengesLack of zoning leads to encroachment and mismanagement of flood plains.
Unsuitable constructions push floods further inland and delay floodwater drainage.
Floodplain degradation affects soil fertility and quality.

 

States have shown resistance to implementing floodplain management, including potential legislation, primarily due to population pressure and the lack of alternative livelihoods.

Current SituationPunjab lacks proper floodplain zoning despite NGT directions.
Four states (Manipur, the erstwhile Jammu & Kashmir, Rajasthan and Uttarakhand) have adopted floodplain zoning on paper but implementation is limited.
Environmental activists and NGOs in Punjab are advocating for floodplain zoning.

 

NDMA guidelines:

As per guidelines on floodplain zoning by the National Disaster Management Authority, defence installations, industries, and public utilities like hospitals, electricity installations, water supply, telephone exchanges, aerodromes, railway stations, commercial centres, etc. should be located such that they are above the levels corresponding to a 100-year frequency or the maximum observed flood levels.

 

NGT direction:

According to the National Green Tribunal (NGT), there should be no construction within a 500 m area from the central lining of a river.

 

Model Bill for Flood Plain Zoning:

The Model Bill for Flood Plain Zoning outlines provisions for flood zoning authorities, surveys, delineation of flood plain areas, notification of limits, prohibition of flood plain use, compensation, and crucially, removal of obstructions for unimpeded water flow. It proposes replacing low-lying settlements with parks and playgrounds to reduce the loss of life and property.

  

Mains Links:

What is floodplain? What is its ecological significance? Floodplains of some of India’s rivers are said to be under severe pressure from various anthropogenic activities. Examine these activities and their impact on floodplains. (15M)