AQA GCSE Geography (8035) — Challenges in the human environment
In the 1960s, the average UK resident used just 85 litres of water a day — today, that figure has rocketed to an average of 150 litres per person. The UK now consumes an estimated 14 billion litres of water daily. Interestingly, only 4% of the drinkable water supplied to homes is actually used for drinking.
There are four main factors driving this massive increase in water demand:
To manage domestic demand, households can install a water meter, which charges users based on exactly what they consume, encouraging conservation. Homes can also recycle grey water from sinks and showers to flush toilets or water gardens.
If you look at a map of UK rainfall, it looks completely backwards compared to where most people live. This creates a severe spatial imbalance between water supply and demand.
The North and West of the UK experience a water surplus, where supply exceeds demand. Physically, these areas receive high amounts of relief rainfall (often exceeding 2,000mm annually) because moist air from the Atlantic is forced over highland areas like the Pennines by prevailing south-westerly winds. Human demand here is low due to sparse population densities.
Conversely, the South and East of the UK experience a water deficit, where demand exceeds supply. Physically, these are drier lowland areas receiving less than 800mm of rain annually. However, they house approximately one-third of the UK's population and have intensive agricultural and industrial needs.
When a region cannot meet its water needs either due to a lack of supply or poor water quality, it experiences water stress. The Environment Agency identifies the South East as the most water-stressed region in the UK.
Quantifying Water Scarcity:
How do you get 160 million litres of water from the rainy Welsh hills to the bustling city of Birmingham every single day? The answer is a water transfer scheme — a network of pipes, canals, and rivers that moves water from areas of surplus to areas of deficit.
Currently, only about 5% of the UK's water is supplied this way. A famous example is the Elan Valley Scheme, which moves water 118km from Wales to Birmingham. Because it drops 52m in elevation, it is gravity-fed, meaning it does not require energy-intensive pumping.
The UK's largest transfer project is Kielder Water in Northumberland. Water is stored behind a massive dam and released into the River North Tyne. Pipelines then transfer it to the Rivers Derwent, Wear, and Tees to supply industrial hubs like Newcastle and Middlesbrough.
Impacts of Water Transfer Schemes:
Surprisingly, only about one-third of UK surface water bodies currently achieve a "high" or "good" ecological status under the Water Framework Directive (WFD). The WFD uses a strict "one out, all out" rule, meaning a river fails if even a single chemical element out of 50 falls below standard.
The main sources of UK water pollution include:
Before water becomes potable, it must go through a strict treatment process. First, screening uses metal grills to remove large debris. Second, sedimentation allows heavy sludge to sink. Third, filtration passes water through sand and gravel beds. Finally, chlorination or UV light kills harmful bacteria and pathogens.
To tackle pollution at the source, the government introduced the "Plan for Water" (2023). This top-down legislation introduces unlimited fines for polluting water companies and offers £34 million to farmers to improve slurry management.
Every time a new housing estate is built, acres of absorbent soil are covered in impermeable concrete, increasing both flood risks and urban runoff pollution.
Sustainable Drainage Systems (SuDS) offer a nature-based solution. They are designed to drain surface water more naturally and filter pollutants before they reach rivers. Multiple SuDS components are often linked together in a management train to incrementally improve water quality.
Case Study: Lamb Drove, Cambourne A residential development of 35 affordable houses in Cambridgeshire used SuDS to combat its high flood risk. The project implemented:
The impacts were highly positive. Economically, construction and maintenance were 10% cheaper than traditional pipe drainage. Environmentally, biodiversity improved, with on-site species increasing from 30 to 34, while nearby sites using traditional pipes saw species decline.
Students often confuse 'water deficit' with 'water stress'. Deficit simply means demand is greater than supply, whereas stress refers to the actual inability to meet needs, which can be caused by low supply OR poor water quality.
When AQA asks you to 'Analyse' the spatial imbalance of UK water, you must use specific compass directions and link physical causes (relief rainfall in the North/West) to human causes (high population density in the South/East).
In evaluate questions about water transfer schemes, examiners look for explicit negative environmental impacts, such as how mixing water from different catchments can introduce alien species.
Always distinguish between preventing water pollution at the source (using SuDS or government legislation) and treating already polluted water (using filtration and chlorination).
Water meter
A device that records the exact amount of water used in a property, encouraging conservation as users pay only for what they use.
Grey water
Recycled domestic wastewater from sinks, showers, and baths (excluding toilets) that can be used for non-potable purposes like flushing toilets or irrigation.
Water surplus
A situation where the supply of water exceeds the demand for it, typical of the North and West of the UK.
Relief rainfall
Rainfall that occurs when moist air is forced to rise over highland areas, cooling and condensing into heavy rain.
Water deficit
A situation where the demand for water exceeds the available supply, typical of the South and East of the UK.
Water stress
A situation where water supply falls below 1700 cubic metres per person per year, or where poor water quality restricts use.
Water transfer scheme
A large-scale engineering project that moves water from an area of surplus to an area of deficit via pipes, canals, and rivers.
Potable water
Water that has been treated and is safe for human consumption.
Eutrophication
A process where excess nutrients (like nitrates and phosphates) cause severe algae blooms in water, depleting oxygen and killing aquatic life.
Sustainable Drainage Systems (SuDS)
Environmentally friendly management practices designed to mimic natural drainage, slowing down surface water flow and filtering out pollutants.
Management train
A series of SuDS components (like green roofs, swales, and ponds) used in sequence to incrementally improve water quality and reduce flow volumes.
Put your knowledge into practice — try past paper questions for Geography
Water meter
A device that records the exact amount of water used in a property, encouraging conservation as users pay only for what they use.
Grey water
Recycled domestic wastewater from sinks, showers, and baths (excluding toilets) that can be used for non-potable purposes like flushing toilets or irrigation.
Water surplus
A situation where the supply of water exceeds the demand for it, typical of the North and West of the UK.
Relief rainfall
Rainfall that occurs when moist air is forced to rise over highland areas, cooling and condensing into heavy rain.
Water deficit
A situation where the demand for water exceeds the available supply, typical of the South and East of the UK.
Water stress
A situation where water supply falls below 1700 cubic metres per person per year, or where poor water quality restricts use.
Water transfer scheme
A large-scale engineering project that moves water from an area of surplus to an area of deficit via pipes, canals, and rivers.
Potable water
Water that has been treated and is safe for human consumption.
Eutrophication
A process where excess nutrients (like nitrates and phosphates) cause severe algae blooms in water, depleting oxygen and killing aquatic life.
Sustainable Drainage Systems (SuDS)
Environmentally friendly management practices designed to mimic natural drainage, slowing down surface water flow and filtering out pollutants.
Management train
A series of SuDS components (like green roofs, swales, and ponds) used in sequence to incrementally improve water quality and reduce flow volumes.
