Flooding

Flooding is one of the most destructive natural hazards in South Africa, causing loss of life, displacement of communities, damage to infrastructure, and significant economic losses. South Africa experiences a range of flood types – including riverine flooding, flash floods, and coastal flooding – driven by intense rainfall events, catchment conditions, land use changes, and rising sea levels. The catastrophic KwaZulu-Natal floods of April 2022 served as a stark reminder of the country's vulnerability, particularly in informal settlements and low-lying coastal areas where exposure and adaptive capacity are limited. Climate change is projected to increase the frequency and intensity of extreme rainfall events across parts of South Africa, making flood risk assessment, early warning, and hazard mapping increasingly urgent priorities.

The resources below provide access to flood studies, hazard mapping tools, coastal flood decision support, and AI-driven flood forecasting systems relevant to South Africa and the broader region.

Google AI FloodHub

(See here for more information on this system)

National Flood Studies Programme — A South African programme focused on improving flood estimation methods and design flood guidelines, providing practitioners and researchers with updated tools and regional data for flood frequency analysis

Coastal Flood Hazard Decision Support Tool (DeST) — An interactive decision support tool developed by OCIMS for assessing coastal flood hazard along South Africa's coastline

Early Warning & Real-Time Monitoring

South African Weather Service (SAWS) – Severe Weather Warnings — real-time severe weather alerts including heavy rainfall warnings that precede flood events
Global Flood Awareness System (GloFAS) — global ensemble flood forecasting system operated by the EU Copernicus Emergency Management Service, with river discharge forecasts up to 30 days ahead
Dartmouth Flood Observatory — global archive of large flood events using satellite remote sensing, useful for historical flood analysis

Flood Hazard & Risk Mapping

FATHOM Global Flood Maps — high resolution global fluvial and pluvial flood hazard maps
AQUEDUCT Flood Analyzer (WRI) — World Resources Institute tool for assessing riverine and coastal flood risk at national and sub-national scales
South African National Disaster Management Centre (NDMC) — national disaster risk information including flood disaster declarations and risk assessments by municipality

Coastal Flooding

Coastal Flood Hazard Decision Support Tool (DeST) — An interactive decision support tool developed by OCIMS for assessing coastal flood hazard along South Africa's coastline
OCIMS (Operational Centre for the Integration of Marine and Coastal Information) — already partially covered via DeST but worth linking to the broader OCIMS platform for coastal hazard information
NASA Sea Level Change Portal — sea level rise projections relevant to coastal flood risk assessment along South Africa's coastline

Flood Modelling Tools

HEC-RAS (US Army Corps of Engineers) — widely used hydraulic modelling software for flood plain delineation and flood routing
SWMM (EPA Storm Water Management Model) — urban stormwater and flooding simulation tool particularly relevant for South African cities
Mike FLOOD (DHI) — commercial but widely used in South African flood studies for coupled 1D/2D flood modelling

Historical Flood Data

DWS Hydrological Services – Peak Flow Data — historical peak discharge data essential for flood frequency analysis and design flood estimation
EM-DAT International Disaster Database — global database of natural disaster events including historical flood records for South Africa

Urban & Informal Settlement Flooding

CSIR Urban Resilience Research — research on flood risk in informal settlements, highly relevant given South Africa's urban vulnerability context
Sendai Framework Monitor — tracks progress on disaster risk reduction targets including flood-related losses, useful for policy context