What is water pressure?
These key facts explain the core principles of what makes up water pressure:
1. The pressure of the water in the piped supply system is created by gravity due to the height of the source of the water, for instance a reservoir. It may be created or assisted by using a pump (simulating the effect of gravity).
2. This creates a 'head' of water which is measured in "metres head". (The best way to visualise this is how high up the water will go in a vertical pipe if it were connected to the water main at that point). This means that pressure in the mains will vary, generally properties at a high elevation relative to the source receive lower pressures and properties at a lower elevation receive water at a higher pressure.
3. Pressure also varies in the service pipes which connect properties to the water main. Each service pipe comprises a section of 'communication' pipe which South West Water is responsible for and which may supply one or more properties and a section of 'supply pipe' that customers are responsible for.
4. Supply pipes that are:
- in poor condition with rough inner surfaces or have a leak
- shared by a number of properties
- are very long or have a small bore
will reduce the water flowing in them.
Back to Water Pressure, Supply Interruptions, and Pressure Management