Strategies for Increasing Water Supply (DP IB Environmental Systems & Societies (ESS))

Revision Note

Alistair Marjot

Expertise

Biology & Environmental Systems and Societies

Strategies for Increasing Water Supply

  • Human societies undergoing population growth or economic development need to increase the supply of water or use it more efficiently

  • Water is essential for:

    • Domestic use

    • Agriculture (drinking-water for livestock and irrigation-water for crops)

    • Industry

Strategies Used to Increase Fresh Water Supplies

Strategy

Description

Example

Constructing dams and reservoirs

Structures built to store water, regulate flow and prevent floods

Helps store water during periods of high rainfall for use during dry seasons

The Hoover Dam in the USA creates Lake Mead, supplying water to several states and generating hydroelectric power

Rainwater Catchment Systems

Collecting and storing rainwater run-off from rooftops or other surfaces for domestic use

Collected rainwater can be used for non-potable purposes like irrigation, toilet flushing and cleaning, reducing the strain on freshwater sources

In Chennai, India, rooftop rainwater harvesting helps tackle water scarcity

It also mitigates stormwater run-off, reducing flooding and erosion

Desalination Plants

Removing salt and minerals from seawater to produce freshwater using methods like reverse osmosis

The Jebel Ali Desalination Plant in Dubai provides a significant portion of the city's water supply

Enhancement of Natural Wetlands

Improving wetlands to act as natural filters, removing pollutants and aiding groundwater recharge

The Everglades in Florida, USA, are being restored to enhance water flow and quality

Improving Irrigation Methods

Using efficient irrigation techniques like drip irrigation to reduce water wastage in agriculture

In Israel, the development and use of advanced drip irrigation technology has maximised water use efficiency

Water Recycling and Reuse

Treating wastewater for reuse in industrial processes or irrigation

Singapore's NEWater project treats and reuses wastewater, reducing reliance on imported water

Artificial Recharge of Aquifers

Increasing groundwater supplies by directing surface water into the ground to replenish aquifers

Recharging aquifers helps prevent groundwater depletion and maintains a sustainable supply of water for wells and springs

In California, USA, managed aquifer recharge projects help counteract over-extraction of groundwater

Redistribution

Efficient water redistribution systems, such as canals and pipelines, transfer water from water-rich regions to areas experiencing scarcity

Redistributing water resources can help balance supply and demand, particularly in densely populated or arid regions

The Central Arizona Project in the USA redistributes water from the Colorado River to arid regions of Arizona

Using a combined approach

  • Sustainable management of freshwater resources requires a combination of strategies to enhance water supplies

    • Dams, reservoirs, rainwater catchment systems, desalination plants and enhancement of natural wetlands are effective approaches to increase water availability

    • However, these measures can be complemented by water conservation practices, recycling and reuse, recharging of aquifers and sustainable agriculture

  • By adopting a comprehensive and balanced approach, societies can ensure the sustainable use of freshwater resources

Exam Tip

Make sure you understand the role of wetland ecosystems. They are not just valuable habitats for a huge variety of species—they are also crucial for human societies as they provide essential services like water purification and groundwater recharge.

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Alistair Marjot

Author: Alistair Marjot

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.