Water use in the UK has risen by 70% since 1985 and the demand is set to increase by another 5% by 2020.
Why has demand for water increased?
Increase in wealth
Changes in personal hygiene
Out of season growing of food in greenhouses
Increased industrial production
Increased leisure use
Increasing population
More houses being built
Water quality and pollution management
Sources of water pollution:
Nitrates and phosphates from fertilisers.
Detergents from dishwashers and washing machines.
Heavy metals from industrial waste.
Pollutants from vehicles.
Pesticides and weed killers.
Leaching from underground mines.
Water used in industrial cooling systems.
Acid rain.
Washing cars.
How does water pollution affect the UK?
Increased fertilisers can increase nutrients in the water, speeding up the growth of algae and leading to eutrophication. This means there may not be sufficient oxygen in the water, so other wildlife will also die. The increased algae may also block the sunlight to other water plants.
Toxic waste can poison wildlife. Sometimes the toxins can be transferred to humans if they eat the shellfish or fish, leading to birth defects and in some cases cancer.
Increased water temperatures can lead to death of wildlife and disrupt habitats.
The supply of drinking water can be poisoned.
The micro bacteria in sewage can cause the spread of infectious diseases in aquatic life, animals and humans.
Pesticides can kill important parts of the ecosystem.
People whose livelihoods depend on a clean water supply, for example fishermen or workers in the tourist industry may suffer.
How is water quality managed in the UK?
Legislation- The UK and EU have strict laws which ensure that factories and farms are limited in the amount and type of water (cleanliness) they put into rivers. Water companies which provide our drinking water and sewage systems have very clear regulations and penalties.
Education campaigns- These inform the public about the damage caused by putting inappropriate items into the sewage systems, such as engine oil and baby wipes, and advise how to dispose of the correctly.
Pollution traps- For example, when news roads and motorways are built close to rivers and watercourses, pollution traps such as reed beds are often installed to ‘catch’ and filter out the pollution.
Green roofs and walls- In cities, new buildings often have green roofs, which filter out the pollutants naturally in rainwater. Green roofs also offer excellent sustainable water management. This reduces the risk of flooding by reducing run off from the roof. Green roofs can also help to combat climate change by increasing the absorption of CO2 from the atmosphere.
Building better treatment plants and investing in new infrastructure- Better sewers and water mains can prevent spills and accidents, but can lead to higher water and sewage bills to pay for the investment. For example, Thames Water in London is investing heavily in its sewage works, and new tunnels to prevent the overflow of the current sewers.
Waste water treatments- Local water treatment plants remove suspended solids such as silt and soil, bacteria, algae, chemicals and minerals, to produce clean water for human consumption. They use a number of processes to do this.
Matching supply and demand – areas of deficit and surplus
The north and west of the UK has a water surplus – high rainfall, low evaporation rates, low population density.
The south and east of the UK has a water deficit - lowest annual rainfall and most densely populated, so a higher demand for water.
The need for transfer to maintain supplies.
Water transfer involves matching water supply with demand by moving water from an area with water surplus to areas with water deficit.
The British government has considered setting up a national water grid, similar to the national grid for electricity, where the water would flow though pipes from areas of surplus such as Wales to areas of deficit such as London. The idea has been discussed for many years but has not yet been put into practice, partly due to the enormous costs involved.
An Example: The Kielder Water reservoir in the north west receives lots of rain (water surplus), so water is stored here and transferred to other parts of the UK that have less water (water deficit). Some water is pumped to Newcastle in the east and some water travels as far south as London
There are some concerns including:
The impact on the environment of the river basin in the source area.
Dams constructed to create reservoirs on rivers (may disrupt the ecology and block migrating species).
The increased carbon emissions linked to pumping water over long distances.
The displacement of local communities.
Potential droughts in river source basins caused by the removal of water to other areas.