Chapter XI, Disaster Management

What the chapter covers

Chapter XI, Disaster Management addresses how urban planning and building controls can reduce loss of life and property from earthquakes, cyclones, floods, landslides and tsunamis. It says preparedness and planning are essential because natural disasters cannot be prevented or reliably predicted.

The chapter defines natural hazard-prone areas as places exposed to moderate to very high earthquake or cyclone damage, significant flooding, tsunami risk, landslide risk, or a combination of these hazards.

Hazard classification in Chennai

The Chennai Metropolitan Development Authority identifies the following conditions in the Chennai Metropolitan Area:

• The whole Chennai Metropolitan Area falls within Seismic Zone III and is treated as earthquake-prone.
• Cyclone-prone areas normally extend 20 km from the coast. Risks include strong winds, seawater flooding from high waves and flooding caused by heavy storms.
• No part of the Chennai Metropolitan Area qualifies for zoning as landslide-prone.
• Some places along rivers and canals, and some low-lying areas, are susceptible to flooding or inundation during heavy storms.
• Areas directly hit and flooded by a tsunami need to be mapped and may need to be zoned as tsunami-affected areas. The coastal area concerned also falls within the Coastal Regulation Zone extending 500 m from the High Tide Line.

Effect on development and buildings

Development in susceptible low-lying areas is allowed only when the proposal meets applicable standards and receives PWD clearance on measures needed to prevent inundation.

The chapter says existing development controls regulate matters including location, height, floors, setbacks and land use. Local body building rules regulate foundations, structural components, loads, wind pressure, materials and structural safety. It recommends early amendment of local body building rules to add and enforce special provisions for hazard-prone areas.

Preparedness and public administration

The Revenue Administration, Disaster Management and Mitigation Department is identified as the nodal agency in Tamil Nadu for the Government of India and United Nations Development Programme Disaster Risk Management programme. Recommended measures include:

• Public awareness and hazard mapping.
• Preparedness and response plans at ward, zone and city levels.
• Training for engineers, architects, officials and volunteer teams.
• Review of building practices and safety requirements.
• Periodic review and updating of disaster management plans.

District mechanisms include disaster management committees, emergency operation centres, warning systems, search and rescue, medical response, temporary shelters, relief planning, recovery and reconstruction planning, control rooms and mock drills.