Chapter 0
FLOODS
Floods occur when water overflows or soaks land that is normally dry. Climate change is accelerating the severity and intensity of flooding worldwide. There are three common flood types:
Occur when the water level in a river, lake or stream rises and overflows onto the neighbouring land. The water level rise could be due to excessive rain or snowmelt.
Occur when extreme rainfall creates a flood independent of an overflowing water body. Includes surface water floods (when urban drainage systems are overwhelmed) and flash floods (intense, high-velocity torrents triggered by sudden rainfall).
Inundation of coastal land by seawater, usually caused by intense windstorm events coinciding with high tide. Can also be caused by tsunamis.
Flooding can disable sanitation facilities and contaminate water supplies, creating breeding grounds for deadly waterborne diseases. Without adequate supply, sewage systems fail and there is insufficient water for basic hygiene needs.
Requires comprehensive disaster management planning, including clean water, sanitation, and mental health support.
- Drowning and Injuries
- Waterborne Diseases
- Vector-borne Diseases
- Chemical Hazards
- Mental Health Impacts
- Displacement and Poor Living Conditions
- Nutrition and Food Security
- Interruption of Health Services
Involves investment in flood resilience, disaster planning, and recovery support for affected communities.
- Property and Infrastructure Damage
- Business Interruption
- Agricultural Losses
- Economic Displacement
- Impact on Long-term Economic Growth
Requires comprehensive preparedness and response plans to reduce disruption and long-term impacts.
- Displacement and Homelessness
- Health and Well-being
- Social Cohesion and Community Networks
- Crime and Security
- Disruption of Schooling
- Loss of Educational Materials
- Long-term Educational Outcomes
Requires policy, community action, and sustainable practices to protect ecosystems and enhance resilience.
- Soil Erosion and Degradation
- Water Quality Contamination
- Habitat Destruction
- Impact on Flora and Fauna
- Wetland and Ecosystem Disruption
- Waste and Debris Accumulation
- Increased Risk of Landslides
- Salinization of Soil and Water
PPreparedness
EEmergency
LLong-term
MMitigation
AAdaptation
RResilience
- Disaster Preparedness Planning
- Early Warning Systems
- Infrastructure Protection
- Flood-resistant WASH Facilities
- Community Training Programs
- Stock Prepositioning
- Drainage Improvement
- Land Use Planning
- Elevated Water Points
- Flood-proof Latrines
- Rapid Response Teams
- Alternative Water Sources
- Emergency Hygiene Kits
- Community Resilience Building
- Ecosystem-based Solutions
- Climate-smart Agriculture Integration
| Type | Technology / Tool | Phase | Action | Info |
|---|---|---|---|---|
| Water | ||||
| Technology | River and Lake Water Intake | P | M | → |
| Groundwater Dam | EL | M | → | |
| Protected Borehole | — | — | → | |
| Protected Dug Well | — | — | → | |
| Cross-Cutting | Area- and Situation-Specific Conditions | — | — | → |
| Urban Water Supply in Protracted Crises | — | — | → | |
| Sanitation | ||||
| Technology | Single Ventilated Improved Pit (VIP) | — | — | → |
| Twin Pit Dry System | — | — | → | |
| Raised Latrine | — | — | → | |
| Drainage Systems | — | — | → | |
| Cross-Cutting | Resilience and Preparedness | — | — | → |
| Hygiene Promotion | ||||
| Tool | Transmission Routes and Barriers (F-Diagram) | — | — | → |
| Community Cleaning Campaigns | — | — | → | |
| Community Education: Awareness Campaigns | — | — | → | |
Rainfall monitoringForecast heavy rainfall, especially following prolonged dry periods
Tidal forecastingForecast high tides combined with storm activity
Source vulnerabilityUnprotected springs/wells or supplies without a water safety plan
Rainwater systemsHarvesting systems without a first-flush device in place
Access routesRoads/paths to water sources that become impassable during flooding
Storage capacityAvailability of water storage containers at household level
Water qualityIncreased levels of E. coli or other pathogen concentrations
Sanitation exposureFacilities located in areas prone to flooding
Containment breachReports of deliberate opening of treatment/containment units during flooding