Who supplies my water in the UK?

Last Updated - 17 Oct, 2020

If you’ve recently moved to a new house, you’re probably going through the process of setting up accounts with all your different utility providers. And you may well be wondering ‘who supplies my water?’


Your water supplier is responsible for providing clean, safe drinking water to your home at a reliable pressure. In many cases they are also responsible for sewerage services, which involves taking away the waste water from your home. 


Hopefully the previous owner or tenant in your home has left behind details of your current utility suppliers. But if they didn’t, you can quickly check who supplies your water by visiting Water.org.uk

Who supplies my tap water in the UK map region hard water and soft water
Can I switch water suppliers?

Unlike gas or electricity, UK domestic water customers do not currently have a choice of water suppliers. Business customers do have some choice, but as a domestic customer you have to use the water supplier who holds the rights to supply the area that you live in.


This means you can’t shop around for the best option, so it’s important to find out if you have hard or soft water. If you live in London, you might want to know if your tap water is safe to drink.

What is water hardness? And what are the disadvantages of hard water?

When people talk about hard water, they are referring to water which has high levels of mineral deposits in it. Hard water has more than 120mg of calcium carbonate per litre of water, which gives it a distinctive mineral flavour. By contrast, soft water has less than 60mg/L of calcium carbonate and a much more neutral taste.


If you live in a hard water area, you could find that your shower gel and shampoo don’t foam up well and your skin may feel dry after showering. Limescale can also build up in your kettle and washing machine, and even in your central heating system. These can eventually ‘fur up’ and stop working, which could end up being very expensive!


So if you have hard water, you might want to invest in a water softener system which will improve the flavour of the water and reduce the build up of limescale.

Who supplies my water?

Water is supplied to all homes in Scotland by Scottish Water, who are a public company. 


Domestic customers in Northern Ireland have their water supplied by Northern Ireland Water, who are a Government-owned company.


And if you live in England or Wales, your water will be supplied by a private company. These private companies are shown in the colour coded map shown above. The Water UK website will also show you which company provides water in your area. 

As we mentioned above, you can’t currently change water suppliers if you are a domestic customer. So to give you an idea of the quality and hardness of your water, our water hardness map shows the areas served by UK water suppliers together with the water hardness in the area.

How hard is my water?

To give you an indication of the water hardness in your area, we’ve pulled together details of all the water companies which serve UK domestic customers. 


We’ve ranked the companies by water hardness so that you can easily compare water suppliers and see which companies supply hard water areas. We have also included the company’s contact details and their rating on Trustpilot, which rates companies on the standard of their customer service. Some companies like Thames Water seem to be providing the hardest water in the UK with a Total Dissolved Solid (TDS) amount of 265. They also seem to have the worst rated customer service with an overall rating of 1.3 stars out of 5 and close to 500 reviews. On the other hand, Scottish Water supplies the smoothest water in the country with a TDS amount of 80. The overall best water supplier in the UK is South West Water with a Trustpilot rating of 4.8 out of 5 and smooth water with a TDS amount of 100.

It is also interesting to notice that the harder the water is in an area, the more likely will the user view their water supplier negatively. See details below. For example let’s take the 3 companies with the softest water: Scottish Water - Dwr Cymru - Northern Ireland Water. Trustpilot awards them an average of 3.8 out of 5. Now if we compare with the companies delivering the hardest water in the UK: Thames Water - Affinity Water - Severn Trent Water with an average of 2.3 out of 5. This data goes to prove that hard water affects more than just the taste of your water but your overall satisfaction towards your water supplier

Scottish Water - Green 

⦁          www.scottishwater.co.uk

⦁          Water hardness: 80 - Very Soft

⦁          UK Trustpilot score: 3.4 (2 reviews) 

Dwr Cymru (Welsh Water) - Yellow

⦁          www.dwrcymru.com

⦁          Water hardness: 80 - Very soft

⦁          UK Trustpilot score: 4.2 (104 reviews)

Northern Ireland Water - Orange

⦁          www.niwater.com

⦁          Water hardness: 100 - Soft

⦁          No reviews on Trustpilot

South West Water - Light Blue

⦁          www.southwestwater.co.uk

⦁          Water hardness: 100 - soft 

⦁          UK Trustpilot score: 4.8 (498 reviews)

Yorkshire Water - Pink

⦁          www.yorkshirewater.com

⦁          Water hardness: 100 - soft

⦁          UK Trustpilot score: 2.6 (107 reviews)

Northumbrian Water - Blue

⦁          www.nwl.co.uk/contact

⦁          Water hardness: 130 - moderate hardness

⦁          No reviews on Trustpilot

Southern Water - Dark Purple 

⦁          www.southernwater.co.uk

⦁          Water hardness: 130 - moderate hardness 

⦁          UK Trustpilot score: 1.6 (109 reviews)

United Utilities Water - Red

⦁          www.unitedutilities.com

⦁          Water hardness: 130 - moderate hardness

⦁          UK Trustpilot score: 3.2 (297 reviews)

Wessex Water - Light Green

⦁          www.wessexwater.co.uk

⦁          Water hardness: 130 - moderate hardness

⦁          UK Trustpilot score: 4.7 (3,394 reviews)

South East Water - Very Dark Red

⦁          www.southeastwater.co.uk

⦁          Water hardness: 150 - hard

⦁          UK Trustpilot score: 1.8 (22 reviews)

Anglian Water - Dark Green 

⦁          www.awg.com

⦁          Water hardness: 180 - hard

⦁          UK Trustpilot score: 3.9 (129 reviews)

Bristol Water - Purple

⦁          www.bristolwater.co.uk

⦁          Water hardness: 180 - hard

⦁          UK Trustpilot score: 4 (3 reviews)

Portsmouth Water - Very Dark Brown

⦁          www.portsmouthwater.co.uk

⦁          Water hardness: 180 - hard

⦁          UK Trustpilot score: 3.8 (2 reviews)

Severn Trent Water - Blue/Green

⦁          www.stwater.co.uk

⦁          Water hardness: 180 - hard

⦁          UK Trustpilot score: 2.8 (140 reviews)

Affinity Water - Dark Brown

⦁          www.affinitywater.co.uk

⦁          Water hardness: 200 - hard

⦁          UK Trustpilot score: 3.0 (68 reviews)

(formerly known as Veolia Water Central, Veolia Water East, Veolia Water Southeast)

Thames Water - Dark Black

⦁          www.thameswater.co.uk

⦁          Water hardness: 265 - very hard

⦁          UK Trustpilot score: 1.3 (483 reviews)

Scottish Water trustpilot score, tap water score
Dwr Cymru Water trustpilot score, tap water score
South West Water trustpilot score, tap water score
Yorkshire Water trustpilot score, tap water score
Southern Water trustpilot score, tap water score
United Utilities Water trustpilot score, tap water score
Wessex Water trustpilot score, tap water score
South East Water trustpilot score, tap water score
Anglian Water trustpilot score, tap water score
Bristol Water trustpilot score, tap water score
Portsmouth Water trustpilot score, tap water score
Severn Trent Water trustpilot score, tap water score
Affinity Water trustpilot score, tap water score
Thames Water trustpilot score, tap water score

Now you know which water company is supplying water to your home, and whether you have hard or soft water. If you have hard water, installing a water softener system will make your water taste better as well as reducing the risk of limescale damage. The Sküma device is here to help for that! Check out how Sküma transforms tap water into mineral water.

By Alex written on the 15 Oct 2020