What is flood plain zoning and why we need to know about it

This November, the central government of India demanded reports form a few states on their preparedness and response to floods. The move came against the backdrop of massive flooding due to winter rains in the southern part of the country. The central government’s demands included details on the implementation of flood plain zoning. The states in question had seen flash floods and landslides in the last two to three years, and it seems the level of destruction from these incidents might be lessened, though stopping floods may not be within human control.  

What is flood plain zoning?  
Zones in danger of flooding are ranked and earmarked by either the state or central governments of most countries according to the severity of risk. This zoning does not go by history of recent flooding. It follows a more studied approach according to geography, topography (the gradient or slope of the land), and climactic changes. The aim is always the same – reduce flood risk to nearby communities and property – by letting them know of the danger in advance.  

How are flood plains demarcated?  
Both areas near but not adjacent to rivers, as well as river banks / deltas can be marked as floodplains. The areas near the river might be lower than its immediate surroundings, making them open to flooding. The banks are more prone to landslides and flash floods. Flash floods and flooding through overflow occur in areas with dams and smaller river connected with the big river. Governments tag these places as low-to-moderate risks, high risks, coastal areas, and undetermined risks. Most importantly, flood plain zoning outlines permissible developments in these zones. It means if people build indiscriminately into the flood plain, they end up opening themselves to flood threats. Local civic bodies are supposed to stop these constructions.  

What can government authorities do to ensure safety in flood zones?  
Flood-plain zoning helps governments pass orders that restrict land use in such areas, for both construction and farming. They can also specify building standards and construction materials for that region, create dam management plans, flood shelters, and ask people to buy flood insurance.