The Impacts of River Flooding

River flooding can have wide-ranging impacts on people, the economy and the environment. These impacts can be short-term or long-term, and positive or negative, depending on the scale of the flood and how well the area is prepared.

Social Impacts

Loss of Life and Injury

• Fast-flowing floodwater can be extremely dangerous.
• People may drown or be injured by debris carried by the water.
• Vulnerable groups such as the elderly and young children are most at risk.

Displacement of People

• Homes may become uninhabitable due to flood damage.
• Families may be forced to evacuate to temporary accommodation.
• Long-term displacement can cause stress and disruption to daily life.

Health Impacts

• Floodwater may be contaminated with sewage, chemicals and waste.
• This increases the risk of waterborne diseases.
• Standing water left behind after floods can encourage the spread of insects and illness.
• Access to clean drinking water may be reduced.

Economic Impacts

• Damage to Property and Infrastructure
• Flooding can damage houses, businesses and public buildings.
• Roads, bridges, railways and power supplies may be destroyed or disrupted.
• Transport disruption can prevent people from getting to work or school.

Financial Costs

• Repairs to homes and infrastructure are expensive.
• Businesses may be forced to close temporarily or permanently.
• Insurance costs may rise, or insurance may become unavailable in high-risk areas.
• Governments often face high costs for emergency response and rebuilding.

Loss of Income

• Farmers may lose crops and livestock.
• Businesses may lose stock and customers.
• Tourism may decline following flood events.

Environmental Impacts

Damage to Ecosystems

• Floodwater can destroy habitats and wash away vegetation.
• Pollution carried by floodwater can harm wildlife and aquatic ecosystems.

Pollution

• Floods can spread pollutants such as oil, sewage and chemicals across large areas.
• Rivers and soils may become contaminated, affecting ecosystems and farming.

Deposition of Sediment

• Floodwater deposits alluvium on floodplains.
• This can improve soil fertility and benefit agriculture in the long term.
• This is one of the few positive impacts of flooding.

Short-Term vs Long-Term Impacts

Short-term impacts

• Injury and loss of life
• Damage to homes and infrastructure
• Disruption to transport and services

Long-term impacts

• Economic decline in affected areas
• Increased flood protection costs
• Changes in land use and settlement patterns