Water regulations

This section explains the aims of the Water Supply Regulations.

These are requirements for design, installation and maintenance of plumbing systems, water fittings and water-using appliances in domestic and commercial property in England and Wales.

Main requirements

The three main requirements of the regulations are:

  • Plumbing systems, water fittings and water using appliances must be installed and maintained to comply with the regulations
  • Contamination of drinking water must be prevented
  • Advance notice of plumbing installation work must be given.

The regulations are designed to prevent:

  • The inefficient use or waste of water
  • Contamination of drinking water supplies
  • Incorrect measurement of water supplied.

Notification of proposed works

Water Supply (Water Fittings) Regulations 1999



Current situation regarding the Covid-19

In light of the current situation regarding the Covid-19 pandemic, we have found there has been an increased demand for temporary Covid-19 structures to be connected to our network.

We are keen to help you process these requests as smoothly as possible. With this in mind, if these sites require a water supply then we will need to make sure we have the correct water fittings information.

If a water supply is required, please provide the following information to mailto:[email protected]


  • Please send any water system design and layout drawings through as soon as possible
  • A Double Check Valve will need to be installed on the supply pipe (providing whole site backflow protection)
  • Please supply a list of water fittings to be installed to help demonstrate that approved products are being used
  • Please supply information on Zonal and point of use backflow protection
  • Please supply information on Water Safety Plans to prevent contamination of supplies
  • Please supply email contacts of your contractor / Water Safety Manager so that we discuss Water Fittings Compliance


To assist with adhering to Water Fittings Compliance, Southern Water can attend site, provided it is safe to do so. We will accept photograph evidence to encourage working from home and we have Regional Water Regulations Officers that can work closely with you to provide water quickly and efficiently.

Who has to comply with the Regulations?

Owners and occupiers of premises and anyone who installs plumbing systems or water fittings have a legal duty to ensure that their water systems comply with the Regulations.


Incorrectly installed plumbing that creates contamination of the water supply could lead to prosecution and fines, and the potentially considerable cost of restoring the water system to become fit for drinking purposes.


We are responsible for the enforcement of the Regulations in our water supply area. We will undertake random inspections of new and existing installations to check that the regulations are being applied.

It is a criminal offence to knowingly breach the Regulations and offenders may face prosecution.


The Regulations state that anyone installing new water fittings must ensure they are of the appropriate quality and standard and are properly installed.

Complying with the Regulations prevents drinking water becoming contaminated with water designed for other uses such as central heating, washing machines, dishwashers and industrial processes.

Where a breach of the Regulations is found, we will require it to be remedied as soon as practicable, subject to the severity of risk. If it poses a risk to health, the supply to the premises may be disconnected immediately.

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