The seas hold 97% of the world’s water and are salty. 2% is frozen in the polar ice-caps.

The remaining 1% is freshwater and provides all the water we use

• it includes all the lakes and rivers of the world
• all the water in the atmosphere
• all the water underground.

All the water in the world’s atmosphere only equals about 10 days’ normal rainfall.

• You can imagine that if water was something we used up like gas or oil, then the world would run dry very quickly.
• We depend on the constant recycling of that 1% of water to meet all our needs.

The Water Cycle

We have a never ending supply of water through a natural process we call the water cycle.

Just like a bicycle wheel, the water cycle has no beginning and no end. It has been the same since time began.

This water or hydrological cycle has to be used sensibly by humans to meet our needs.

Supply and Demand

The rise in (a) population (b) the building of new towns and industry and (c) water-based pass times, have all created an increasing demand for water.

We each use approximately 145 litres of clean treated water every day for washing, cooking, drinking, watering the garden, etc.

Currently Northern Ireland Water supplies around 710 million litres of water each day.

Use Water Wisely

The extraction, treatment, distribution and disposal of water is expensive and effects the environment. Therefore, we all need to use water wisely.

You can ask for one of our free water audit leaflets for either the home, school, business or agricultural premises and work out how your usage compares to the average.

You will be surprised at how much water you actually use.

Leaflets, which provide advice on how to save this precious resource, are also available.

The Amazing Cycle of Water

Evaporation

When the sun shines on the seas, rivers and lakes it turns some of the water into water vapour (gas) this is called evaporation. This gas rises to the sky and it cools again to form clouds and then turns to rain.

Cloud Storage/Rain

When clouds blow across the land and the temperature drops, vapour forms into droplets, which fall back on the land as rain, snow or hail. Rain:

• finds its way to streams and rivers, or
• can pass through porous ground such as chalk or
• can be trapped in man-made reservoirs.

The reservoirs, rivers, lakes and natural underground water stores (aquifers) are the sources of freshwater we use.

Reservoir

This water then finds its way to streams and rivers, or it can percolate through porous ground such as chalk or it can be trapped in man-made reservoirs. The reservoirs, rivers, lakes and natural underground water stores (aquifers) are the sources of water we use at home and at work.

Water Treatment Works

Northern Ireland Water enters this natural cycle and makes sure that the water we use is clean and safe. This is done at a Water Treatment Works, where it is filtered and bacteria are removed. The water is then supplied through a network of pipes to homes, schools, factories and to all other users.

Wastewater Treatment Works

Used water from our baths, washing machines, sinks and toilets, together with rain that runs into the sewers, is called wastewater or sewage. Before it is put back into the sea is has to be cleaned, this happens at a Wastewater Treatment Works.