Monsoon floods in India - Causes and flood management

What is a flood?

In its simplest form, a flood occurs when high levels of water, invade areas which are usually characterized by dry land, and the rise in water levels overtakes the capacity of pre-existing drainage mechanisms in the area, leading to water accumulation causing damage and disrupting normal life.

Types of Floods and Causes

There are several kinds of floods caused by different factors, as well as differing in the damage they cause, and the methods of flood management they require.

Fluvial or river floods: These occur when the water level in a river, lake, stream or water body rises due to excessive rain or snowmelt, and overflows on to surrounding lands. Damages from river floods can cascade further by way of flooding smaller rivers downstream, pressuring dams to break and creating swamps and marshland. In flatter lands, floodwater rises slower and remains stagnant for longer. In mountainous terrain, fluvial floods can both rise and drain quickly depending on the height of the ground. It also depends on the soil water saturation of the surrounding terrain.
Pluvial or flash/surface floods: These occur when unusually high rainfall creates a flood in an area, independent of the presence of any water body in the vicinity. These are of two types:
- Flash floods occur when water is suddenly released from an upstream dam or source, causing extensive damage due to the high force of the water as well as debris it uproots in its way.
- Surface floods occur when water levels gradually rise in urban areas due to heavy rainfall causing drainage systems to get overwhelmed, giving people some time to move to safer locations, yet causing severe public health issues and economic damage, by obstructing the normal functioning of the city as well as access to essential services.
Coastal floods occur when land areas along the coastline get submerged under splashes of seawater due to intense windstorms coinciding with a high tide, or due to a tsunami along the coastline.

Hence, floods are caused by both meteorological, physical as well as human factors such as deforestation, unchecked urbanization, and faulty construction of dams.

Flood prone areas in India

India being a geographically diverse terrain, spanning mountainous regions as well as multiple river plains and an extensive coastline, is prone to experience all these different types of floods to varying degrees.

Mumbai, being the financial capital of India as well as a coastal city, which happens to be a bustling metropolis overpopulated beyond its capacity, has witnessed its share of flood disasters. The city of Mumbai is most prone to surface floods. Most of the city historically evolved in an unplanned manner, with an irregularly distributed population density

In blatant defiance of safety guidelines or ignorance of the vulnerability of the city to floods, the city witnessed the construction of residences, offices, factories, and infrastructure facilities in areas vulnerable to floods as well as liable to suffer floods as a consequence of unplanned constructions.

The infamous Maharashtra floods witnessed on 26^th July 2005 caused devastation across Mumbai, Kalyan, Chiplun, Ratnagiri, Khed and Raigad, causing a minimum of 5000 people to lose their lives, as well as unprecedented damage to economic activity and property, with direct loss of Rs 5.5 billion, as well as indirect losses due to most commercial activity of the city coming to a standstill

Similarly, floods occur in monsoons in a wide range of regions nationwide in India. According to an assessment conducted by India's union Home Ministry, the major flood-prone regions in India are Punjab, Haryana, areas of the Gangetic plains, including Uttar Pradesh, north Bihar, and West Bengal, Brahmaputra valley, coastal areas of Andhra Pradesh and Orissa, Kerala, Tamil Nadu, and southern Gujarat. Additionally, Jammu Kashmir, as well as Uttarakhand, have recently experienced devastating floods and landslides due to torrential rainfall.

Current Status of Flood Management In India

India’s flood management mechanisms exist by way of

Engineering or structural measures, and
Administrative or policy measures

Engineering measures include

Flood Plain Zoning
Forecasting of Floods through CWC National Flood Forecasting Network
Channelizing of Rivers
Drainage Improvement
Embankments
Water Reservoirs

Administrative or policy measures are at both:

Central level, comprising the Central Water Commission (CWC), the National Disaster Management Authority (NDMA), the Ganga flood control commission, and the Brahmaputra board.
State-level, comprising the water resource department, the flood control board, and the state technical advisory committee.

The roles of the entities at these different levels vary in terms of the challenges within their jurisdictions, the extent of scope and responsibility, as well as in terms of budgets and resources available.

While the N.D.M.A considers flood-related disasters as a sub-set of its overall responsibilities for damage control in the aftermath of different disasters which may occur in the country, the CWC works towards flood control measures, conserving water resources and utilizing water beneficially by generating hydropower, as well as channelizing it for irrigation.

The river wise flood control boards are entrusted with the responsibility to protect the river banks, ensure that the area is not eroded, and keep monitoring the state of the river to raise an alert when risks of flooding are high.

While agencies and mechanisms are being put in place to enable effective flood management in India, the reality is that most measures stay on paper or in theory only, while implementation lacks effectiveness.

A report published in 2017 by the Comptroller and Auditor General (CAG) about India's performance audit on flood control and management schemes categorically stated that around 15 states and union territories display an absence of adequate flood forecasting mechanisms. Until as late as 2016, only 5% of the 4862 dams in India had even an operation maintenance manual.

Perhaps the core issue remains that our disaster management agencies continue to be reactive rather than proactive or preventative in their efforts. When control measures are ultimately effected, it turns out to be a case of ‘too little, too late’.

Measures to be taken for Improving the Flood Management in India

At the central level, the NDMA needs to work towards strengthening systems for forecasting and preparedness.
At the community level, neighborhoods need to be ready for disaster preparedness and damage control.
The construction of residences or habitations should be avoided in flood-prone or high-risk areas.
At an individual level, families need to be alert to flood warnings and keep emergency rations ready to evacuate their homes and relocate at short notice.
In addition, walking in flooded areas should be avoided if the ground is not visible, to prevent accidents of slipping into open drains or on slippery ground.
The aftermath of floods often renders water unsafe for drinking and raises the risk of diseases associated with stagnant water, such as malaria, dengue, and waterborne infections.
The state-level agencies need to align and effectively bridge the information from ground level to the national level, and appropriately channelize distribution of resources from the national level towards the affected areas.

In conclusion, while India has clear priorities assigned to disaster management, there is a wide gap to be bridged between intentions and reality. Despite claims of effective disaster management mechanisms being planned, every year brings with it fresh evidence of failure, in the form of loss of life and property during floods.

It is the need of the hour for the different stakeholders involved in flood management, to be proactive and collaborate across national, state and community levels.