Multipurpose Dams (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Uses of multipurpose dams

• Multipurpose dams are large dams built to provide several different services from a single reservoir

• They help manage water resources for people, farms, industry and the environment

• A single dam can support energy production, farming, transport, fishing and tourism

Flood control

• Dams hold back excess water during heavy rainfall

  • Reduces the risk of downstream flooding

• Water can be released slowly and safely through controlled channels

  • Helps protect homes, farmland and infrastructure

Hydro-electric power

• Water released from the dam turns turbines

  • Turbines spin a generator to produce electricity

• Provides a renewable and often reliable energy source

Irrigation

• Reservoir water can be directed into irrigation canals or pipes

  • Provides farms with a steady supply of water in dry periods

  • Supports crop growth and increases food production

Storage of water

• A reservoir stores fresh water for drinking, industry and farming

• Useful during dry seasons or droughts

• Helps communities plan for periods of low rainfall

Transport

• Reservoirs create calm, deep water suitable for boat transport

  • Can replace rivers that may be too shallow or fast-flowing

• Can be used for moving people or goods in certain regions

Recreation

• Reservoirs provide spaces for activities such as boating, fishing and swimming

• Attracts local people for leisure and sport

Tourism

• Dams and reservoirs can become tourist attractions

• Visitors may come for scenery, boat trips or guided tours

• Provides jobs and income for nearby communities

Fish farming

• Calm reservoir waters are suitable for aquaculture

• Farmers can raise fish in cages or designated areas

• Helps increase food supply and supports local economies

Benefits & limitations of multipurpose dams

Benefits of multipurpose dams

• Provide multiple services from a single structure (flood control, energy, irrigation, tourism)

• Supply renewable electricity, reducing reliance on fossil fuels

• Offer a reliable water source for cities, farms and industry

• Help protect communities from flooding

• Create new economic opportunities in tourism, fish farming and transport

• Encourage regional development by improving water and energy security

Limitations of multipurpose dams

• Very expensive to build and maintain

• Flood large areas of land to create the reservoir

  • May destroy wildlife habitats

  • Can force people to relocate from their homes

• Trap sediment behind the dam

  • Reduces the amount of nutrient-rich silt reaching farmland downstream

• Can reduce river flow downstream

  • Harms ecosystems and affects communities that depend on the river

• Risk of displacement of wildlife and loss of biodiversity

• If poorly managed, sudden releases of water can cause downstream flooding