Downloading content for offline mode
Cancel download
Epidemic Control Toolkit
for community volunteers
Switch to response managers
hamburger icon


Last update: 2022-11-14

Key facts

Flooding is a common disaster exacerbated by climate change. Acute and/or severe flooding can cause loss of life, significant infrastructure damage (including disruption to water and sanitation facilities, bridges and roadways, etc.) and displacement of the affected population.

Floods are often characterized by difficulty in accessing certain geographical areas. Depending on the severity, it can take days or weeks for floodwater to recede.

Floods can damage health facilities and interrupt services, impacting access to essential care.

Main health impacts

Health concern

Risk factors

Mental health consequences

  • Mental health impacts including (but not limited to) severe anxiety, post-traumatic stress disorder (PTSD), and depression may occur as a result of experiencing the trauma of a flood (for example, homelessness; losing loved ones; loss of livelihood; etc.).

  • Experiencing multiple traumatic events can lead to compound or complex trauma.

Trauma (injury) and drowning

  • During and in the immediate aftermath of a flood, rising flood waters and debris often result in trauma and/or drowning.

  • High rates of infected wounds should be expected.

Diarrhoeal diseases

  • Contamination of water supply can be caused by flood water or by damaged or destroyed sanitation facilities.

  • Difficulty maintaining proper sanitation and hygiene practices can lead to an increase in diarrhoeal diseases.

Vector-borne diseases and snake bites

  • Flooding and break-down in waste management and sanitation services can lead to areas of stagnant water and an increase in certain vector (for example, mosquito) breeding sites.

  • Interruption of solid waste management can result in certain vectors (for example, rats) coming into closer contact with humans (due to increased feeding sites and breeding grounds).

  • Flooding also leads to displacement of animals and insects, including venomous snakes. Snakes seeking food and shelter are more likely to come into close contact with humans, increasing the risk of venomous bites.

Respiratory illnesses, skin disease and vaccine- preventable diseases

  • Flooding may lead to population displacement. Overcrowded, communal emergency shelters, coupled with difficulty maintaining proper sanitation and hygiene practices can lead to problems such as respiratory illnesses, skin diseases and some vaccine-preventable diseases.

  • Emergency responders and community members may be at increased risk for wounds and injuries that become contaminated with flood waters, soil, dirt, human or animal waste.

  • A major flood can cause severe damage to health facilities and lead to the disruption of routine health services such as vaccination programmes, increasing the risk of transmission of vaccine-preventable diseases.


  • In both the short and long term, flooding can lead to an interruption in food supply. Loss of food stocks and crops can cause food insecurity and may increase the risk of malnutrition.

Other resources