Water pressure

Information

Do you want to know the water pressure in your street? Are you having a new shower, boiler or other appliance fitted?

Please contact us if you would like to know the pressure in the water mains feeding your property. Call 01202 590059 or email customerservice@sembcorpbw.co.uk. (Calls are answered in person from 8 am until 6 pm Monday to Friday and from 9 am to 2 pm on Saturdays.)

The pressure will depend on your location and may vary at different times of day. Water pressure can be affected by many factors, such as:

• the difference in height between your property and the reservoir that feeds you
• the distance from the reservoir to your property
• the length and diameter of the pipes in the supply network
• whether the water is pumped and if so, when and at what pressure
• whether your area has any pressure control in place
• the demand for water in the supply area

There may also be a difference between the pressure in our mains in the road outside your home and the pressure inside your home. This could be due to:

• the ground level of our water main compared to your property
• the number of floors in the property and, if you are plumbing in an appliance, the floor on which it is located
• the length of your underground supply pipe  (this usually runs from the boundary stopcock in the road to the first internal stopcock inside the property), the diameter of the supply pipe and its condition as leaks can reduce pressure
• whether you are on a shared supply pipe with an adjoining property – flats are often fed by one shared supply pipe
• the size of the pipework within the property
• the amount of water being used in the property at any one time

The requirement

We must comply with certain standards set out in the Water Industry Act 1991 Part III Chapter II "Means of Supply " Section 65.

We are required to supply water constantly and at a pressure which will reach the upper floors of buildings. This does not apply to buildings using pumped systems, such as blocks of flats. We are not required to supply water to a height greater than that to which it would flow by gravitation through our water mains from the reservoir.

For more information on water pressure, go to the website of the water industry regulator, Ofwat.

Minimum standard

We must supply a pressure of not less than ten metres head (1 bar). This is the height that water would reach in a vertical pipe. This pressure level applies to the communication pipe supplying your property (the pipe that goes from our main, usually to the boundary of your property) for a flow of nine litres per minute inside the property.

In most areas the pressure is higher than this. Our regulator, Ofwat, requires us to report the number of properties that receive pressure lower than this standard each year.

The minimum standard for pressure is called ‘the level of service indicator’, known as DG2. This level of service does not override our duty to supply water constantly at a pressure to reach the upper floors of properties.

Problems?

See Domestic customers > Problems? > No water or low pressure