Water Regulations Information Hub
Clear, practical guidance on UK water fittings requirements, backflow protection and fluid categories — written for property managers, business owners and facilities teams.
The Water Supply (Water Fittings) Regulations 1999
In England and Wales, the Water Supply (Water Fittings) Regulations 1999 set the requirements for plumbing systems, water fittings and water-using appliances connected to the public water supply. Their purpose is to prevent waste, misuse, undue consumption, and — most importantly for backflow — contamination of the water supply.
The regulations place duties on property owners and occupiers to ensure their water systems are designed, installed and maintained so they do not risk contaminating the public supply. This includes providing suitable backflow protection where a risk exists, and in some cases notifying the water undertaker before carrying out certain works.
Dive deeper into each topic
Fluid Categories 1–5
What the five fluid categories mean and how they determine the level of backflow protection required.
Read moreBackflow Prevention
How backflow occurs, the types of prevention device and where each is appropriate.
Read moreCommercial Compliance
Practical guidance for property managers and facilities teams on meeting water fittings requirements.
Read moreWater Fittings Regulations
An overview of the Water Supply (Water Fittings) Regulations 1999 and differences across the UK.
Read moreKey responsibilities at a glance
Prevent contamination
Provide suitable backflow protection wherever a risk to the supply exists.
Use compliant fittings
Ensure fittings and materials meet the requirements and are suitable for their use.
Notify where required
Some installations require advance notification to the water undertaker.
Maintain protection
Keep backflow prevention devices, including RPZ valves, tested and serviced.
Allow inspection
Water undertakers can inspect installations to check compliance.
Keep records
Retain test and compliance documentation for your premises.