Water Regulations for your business

Did you know all premises that have a water supply from Welsh Water are legally required to ensure their plumbing systems comply with The Water Supply (Water Fittings) Regulations 1999? Essentially, everything on a customer’s side of the boundary is required to comply.

If you don’t know what is covered by the regulations, then you can find a diagram explaining them below. While Welsh Water owns and fixes the section on the far left of the diagram, the Regulations apply to the two sections on the right: your private supply pipework and your internal pipework and fittings.

Why are the regulations in place?

These regulations are in place to protect public health by aiming to prevent the waste, misuse, undue consumption, erroneous measurement, and contamination of water we supply to our customers.

We enforce these regulations on behalf of DEFRA and the Welsh Government and they are essential in protecting public health and the water supply.

We carry out inspections on some of the premises we supply to make sure their plumbing systems comply with these regulations, but we also offer help and support to customers to achieve this compliance through other aspects of our work.

Below is some information on what you can do to comply and how we can help and support you.

How can I comply with the regulations?

  • Provide notification for any plumbing works
    If you are altering or extending an existing non-domestic plumbing system, then we need to be notified before any works are carried out. This allows us to support you in making sure your planned works are compliant with the regulations. This will save any timely or costly alterations when we come to inspect the finished works.
    You can find out more information about when and how to notify us here.
  • Use WaterSafe Approved Contractors
    Did you know that WaterSafe is the national register for approved contractors, such as plumbers and water supply pipe installers? WaterSafe members are suitably insured professionals with a knowledge of the Regulations, meaning that using WaterSafe approved contractors provides you with the reassurance that work they complete will comply. Find your local approved plumber here:

If you manage or contract out to plumbers who are not WaterSafe approved, then we may be able to offer those qualified plumbers eligible for WaterSafe membership free Water Regulations training to help them get approved. Get in touch at WaterRegulations@dwrcymru.com for further information or to register your interest.

  • Get Water Regulations awareness presentations from us
    We also offer Water Regulations awareness sessions, aimed at those who do not need the same level of knowledge as an installer.
    These sessions can be tailored to focus on aspects that are relevant to you and will highlight the importance of compliance for our customers. Contact us at WaterRegulations@dwrcymru.com to request a session.
  • Help us complete any water regulations inspections
    We conduct inspections on some of the premises we supply to make sure they are compliant to the regulations. These inspections are an important part of our duty to make sure our network and water supply remains safe for our customers.
    One of the core parts of this inspection is making sure there is adequate backflow protection in place for any risks identified. You can watch this short video which demonstrates what backflow is and why protection must be in place to prevent it from occurring on your plumbing system:

Should you have an inspection and things are required to be put right, then we will issue you with an infringement notice. You can find more information on these in the leaflets below.

Helpful leaflets

Here are some leaflets to provide you with further information on the regulations and what you can do to comply.

Water Regulations Enforcement Policy 2021

145.5kB, PDF

Water Regulations General Information Leaflet

435.7kB, PDF

Water Regulations Agricultural Premises Information Leaflet

1.1MB, PDF

Water Regulations - Information for Developers, Designers and Installers

646kB, PDF

Code of practice for Leakage - Non Household Customers 2020-2021

188.2kB, PDF

Water Regulations - how they affect your business

346.2kB, PDF

More questions?

You can find out more information about the regulations here.

If you have any questions please feel free to get in touch on WaterRegulations@dwrcymru.com and we will be more than happy to help.