Cambridge IGCSE Geography (0460): Theme 3.6 – Water – Revision Notes

These notes condense the water study guide. Read that first if any idea here is new.

They cover Topic 3.6 Water from the Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022). The topic sits in Theme 3, Economic development, and is examined in Paper 1 Geographical Themes, where you answer three questions, one from each section. Paper 2 knowledge questions can also draw on it, and the syllabus suggests a water-supply enquiry for Component 3 Coursework. When you are ready, try the water practice questions. For other topics, use the Cambridge IGCSE Geography hub and the IGCSE Geography checklist.

What the syllabus asks

• Describe methods of water supply: reservoirs/dams, wells and bore holes, desalination.
• Describe the proportions of water used for agriculture, domestic and industrial purposes in countries at different levels of economic development.
• Explain why there are water shortages in some areas.
• Know the impact of lack of access to clean water on local people and on the potential for economic development.
• Demonstrate that careful management is needed to ensure future supplies.
• Case study: water supply in a country or area.

Key terms

Term	Meaning in one line
Reservoir	Stored body of water, often behind a dam
Dam	Barrier across a river that holds back water
Well	Shallow hole dug to the water table
Borehole	Deep, narrow shaft drilled into an aquifer; water pumped up
Aquifer	Permeable rock that stores groundwater
Water table	Top of the saturated ground
Desalination	Removing salt from seawater to make fresh water
Reverse osmosis	Forcing water through fine membranes to remove salt and impurities
Water transfer	Moving water by pipe, canal or tunnel from a surplus area to a deficit area
Over-abstraction	Taking groundwater faster than it is replaced
Physical water scarcity	Not enough water to meet demand
Economic water scarcity	Water exists, but no investment to supply it
Water stress	Demand close to or above available supply
Drip irrigation	Pipes deliver small amounts of water to plant roots, cutting waste

Supply methods at a glance

Method	How it works	Plus	Minus
Reservoir/dam	Dam stores river water for the dry season	Large, reliable store; may add HEP and flood control	Costly; floods land and homes; evaporation; traps sediment
Well	Hand-dug to shallow groundwater	Cheap, local	Dries up if water table falls; easily polluted
Borehole	Drilled deep; pumped	More reliable, cleaner water; good for rural villages	Pumps need fuel or repair; over-abstraction lowers water table
Desalination	Seawater through membranes or boiled	Does not depend on rain	High energy cost; brine waste; coastal only

Use by level of development

	Agriculture	Industry	Domestic
Low income	Largest by far	Very small	Small share, low use per person
Middle income	Large	Growing fast	Growing with cities
High income	Often smaller share	Often largest share (factories, power-station cooling)	Larger share; high use per person

World figure (FAO AQUASTAT): about 69% agriculture, 19% industry, 12% municipal.

Remember that a pie chart or table shows proportions. A person in a high-income country still uses far more water at home than a person in a low-income country, even if the domestic share looks small. Always quote the figures given in the resource.

Why shortages happen

Physical causes	Human causes
Low annual rainfall (hot deserts)	Rapid population growth and urbanisation
Seasonal or unreliable rainfall	Rising living standards raise use per person
High temperatures and evaporation	Irrigation and industry take large volumes
Drought	Over-abstraction lowers the water table
Few rivers or aquifers; little land to store rain	Pollution from sewage, farms and factories
	Leaking pipes; no money for dams, pipes and treatment

Much of sub-Saharan Africa faces economic scarcity. Arid regions such as North Africa and West Asia face physical scarcity.

Impacts of lack of clean water

On local people: water-borne diseases such as cholera and diarrhoea, worst among young children; hours spent walking to collect water, often by women and girls; missed school; poor hygiene.

On economic development: sick workers are less productive; families spend money on medical care; time carrying water is lost from farming, trade and study; farms cannot irrigate; factories and tourism avoid places without a reliable supply. This creates a cycle in which poverty prevents investment in water, and poor water keeps people poor.

Management strategies at a glance

Aim	Methods
Increase supply	Reservoirs, boreholes, desalination, water transfer, recycled wastewater
Reduce demand	Metering, higher prices for heavy users, water-saving taps and toilets, campaigns
Save water in farming	Drip irrigation, drought-tolerant crops, watering at night
Protect quality	Sewage treatment; controls on farm and factory pollution
Cut losses	Repair leaking pipes
Small-scale, community-run	Hand pumps, rainwater tanks, sand dams

Name a method every time. “Use water wisely” earns nothing on its own.

Case studies at a glance

Place	What	Key facts	One evaluation point
Singapore	Four National Taps	Two-thirds of land is catchment; 17 reservoirs; Marina Barrage 2008; Johor River imports under 1962 agreement to 2061; NEWater from 2002, up to 40% of current needs; five desalination plants	Secure and varied, but energy-hungry and costly; relies on wealth and technology
Lesotho Highlands Water Project	Dams and transfer to South Africa’s Vaal River system	Katse Dam 185 m high, deliveries from 1998; royalties and hydropower for Lesotho	Income for Lesotho, but people lost land and livelihoods; corruption cases

Global facts (WHO): in 2022, 2.2 billion people lacked safely managed drinking water; 115 million used untreated surface water.

Must-know distinctions

• Well vs borehole: a well is shallow and dug; a borehole is deep and drilled.
• Physical vs economic scarcity: not enough water vs not enough investment.
• Proportion vs amount: a small share of a large total can still be a lot per person.
• Increasing supply vs reducing demand: dams and desalination add water; metering, pricing and efficient irrigation save it.
• Impact on people vs on development: illness and lost time affect people; lower productivity and lost investment hold back the economy.
• Describe vs explain: describe = what and where; explain = why, with “because” or “so”.

Mini essay plan

Question: “Careful management is the only way to ensure future water supplies.” How far do you agree? Refer to examples.

1. Introduction: define water stress; demand is rising with population growth and development.
2. Agree: demand-side management is cheap and lasting. Singapore’s conservation tax and higher price above 40 cubic metres a month; household use per person has fallen since 2003. Drip irrigation saves water in farming, the biggest user.
3. Agree: protecting quality and repairing leaks keep existing supplies usable; Singapore loses only about 5%.
4. Disagree: some places need new supply too. Singapore’s NEWater and desalination add water that does not depend on rain; Lesotho’s dams store and transfer water.
5. Evaluate: new supply is costly and may displace people (Lesotho) or need lots of energy (desalination). Low-income countries may need investment more than management.
6. Conclusion: management is necessary but not always enough on its own; give a judgement for your example.

Quick self-test

1. Name the three methods of water supply listed in the syllabus.
2. What is the difference between a well and a borehole?
3. Which sector uses the largest proportion of water in most low-income countries?
4. Give two reasons why industry’s share is higher in high-income countries.
5. Define economic water scarcity.
6. Give two physical causes of water shortage.
7. Give two human causes of water shortage.
8. State two impacts of lack of clean water on economic development.
9. Give one disadvantage of desalination.
10. Name Singapore’s Four National Taps.
11. Give one way to reduce demand for water in farming.

Answers

1. Reservoirs/dams; wells and boreholes; desalination.
2. A well is shallow and usually dug by hand; a borehole is drilled deep by machine and pumped.
3. Agriculture.
4. More factories; power stations need cooling water.
5. Water is available but there is not enough investment in infrastructure or technology to supply it.
6. Low or unreliable rainfall; high evaporation.
7. Population growth; pollution, over-abstraction or leaking pipes.
8. Sick workers are less productive; time collecting water cannot be spent working or studying; investors avoid areas without reliable water.
9. High energy use and cost, or brine waste.
10. Local catchment, imported water, NEWater, desalinated water.
11. Drip irrigation, or irrigating at night to cut evaporation.

Where marks are usually lost

• Naming a supply method but not explaining how it works.
• Using “well” and “borehole” as if they were the same.
• Writing about the amount of water when the question asks about proportions.
• Not quoting figures from the resource in data questions.
• Giving only physical causes of shortage when a question says “explain why”.
• Listing health impacts but not linking them to economic development.
• Writing a case study answer with no place name, dates or figures.
• Saying “save water” instead of naming a management method.
• Giving no judgement in “How far do you agree” questions.

Next

Link water to irrigation in food production, drainage basins in the rivers guide, and access to services in the development unit.

Official syllabus

Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022), Topic 3.6 Water.