Multipurpose Dams (Cambridge International IGCSE Environmental Management)

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

  • This means not every region can afford them

• 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

Exam Hint When evaluating dams, remember to include social impacts (displacement of people) as well as environmental and economic ones. Students often forget this.