Zoning of Flood Plains

Context:

Despite National Green Tribunal’s directions to the Government of Punjab, the state is yet to carry out Flood Plain zoning.

• Flood plain areas of Sutlej, Beas, Ravi and Ghaggar have been encroached upon, making villages along these rivers perennially at risk of floods whenever they swell.

About Floodplains:

• A floodplain (or floodplain) is a generally flat area of land next to a river or stream. 
• It stretches from the banks of the river to the outer edges of the valley.
• Major Processes involved in the natural development of floodplains: 
  • The erosion of a floodplain describes the process in which earth is worn away by the movement of a floodway. 
  • Aggradation (or alluviation) of a floodplain describes the process in which earthen material increases as the floodway deposits sediment.
• Geomorphologically, the floodplains in India are of two types: 
  • Peninsular (found in the Deccan plateau) where there are rock terraces (step-like structures created by lava flows), and 
  • those found in the Himalayan region, which are old, wide and depositional (created by the deposition of sediment). 

Characteristics of Floodplains:

• Seasonal Flooding & Fertility: A flood plain regularly overflows,  which deposits a layer of fine soil, rich mineral salts, nutrient-rich silt, which make the soil fertile.
• Water Storage and Flow Regulation: Floodplains can absorb excess water during periods of high flow, helping to reduce the risk of downstream flooding.
• Dynamic in nature: Floodplains are not static; they continue to evolve as rivers erode, deposit sediment, and change their course over time. 
• Topographical Features: Floodplains often contain oxbow lakes – basically abandoned meandering channels of the river, where it once flowed prior to changing its course.
• Densely Populated: Flood plains are generally densely populated because rivers are a perennial source of water, thus people tend to live in areas where water is available. 

Zoning of Flood Plains:

• Zoning of floodplains refers to the practice of designating different areas within a floodplain for specific land uses and activities based on their vulnerability to flooding and associated risks. 
• Floodplain zoning guidelines:
  • The Central Water Commission prepared floodplain zoning guidelines and the Model Bill for Floodplain Zoning was circulated by the Government of India in 1975. 
  • Four states followed this up by passing floodplain zoning acts: Manipur in 1978, Rajasthan in 1990, erstwhile state Jammu and Kashmir in 2005 and Uttarakhand in 2012. 
  • Acts provide for the establishment of a “Flood Zoning Authority”, to conduct surveys to determine the nature or extent of floodplains, prohibit or restrict the use of land in the floodplains, and impose penalties for non-compliance.

Significance of  Zoning of FloodPlains 

• To manage and regulate development in flood-prone areas, aiming to minimize damage to property, protect human life, and maintain the ecological functions of the floodplain.
• Flood Risk Reduction: Zoning helps to manage and reduce the risk of flood-related damage to property, infrastructure, and human lives. 
  • By restricting or guiding development in areas prone to flooding, communities can avoid or minimize the negative impacts of floods.
• Public Safety: Zoning ensures that areas most vulnerable to flooding, such as floodways, remain free of development. 
  • This prevents people and property from being exposed to fast-moving floodwaters, reducing the potential for casualties and injuries.

News Source: The Indian Express