Guidance on sufficiency of your private water supply

With climate change and the increasing threat to water stability, we encourage you to have contingency plans in place to address both insufficiency in your private water supply and contamination risk. Insufficiency, particularly during extended hot summers, is becoming increasingly likely.

The responsibility for ensuring the sufficiency of any private water supply falls to the owner/occupiers of the premises supplied; the owner/occupiers where the source is located and any other person who exercises management/control of the source. If you live in a privately rented house and are on a private water supply, you need to speak to your landlord to discuss this guidance as he/she would have responsibilities with regard to maintaining the supply.

Contingency plan

Having a contingency plan in place will help you manage any issue and it may help reduce costs. Your plan should include arrangements for the provision of an alternative supply to yourself or all consumers of the supply during the period of insufficiency, or whilst any remedial action to mitigate contamination risk is being carried out.

The plan should include as a minimum:

  • The total number of consumers supplied
  • Typical amounts of alternative water required for each consumer
  • The type of alternative water supply (e.g. provision of bottled water, bowsers or tankers) and where you will refill it

Contingency plan for private water supply

What can I do?

Understand your supply

What is the source?
  • surface water
  • spring
  • well
  • borehole
Who uses the water?
  • single property
  • shared with other properties
  • farms
  • customers
What is the water used for?
  • Own residential supply.
  • Commercial (eg. holiday properties/ campsite) or agricultural (farms with livestock) may use more water than domestic supplies
Has it run dry before?

How frequently if yes


Make regular checks

  • Undertake a weekly visual inspection of the source, storage tanks, distribution pipework, treatment
  • Check for blockages and airlocks, especially in the filters
  • Monitor water levels – especially during periods of warm, dry weather
  • Check wholesomeness of your supply and if in doubt contact your local authority for guidance on sampling and analysis

Be prepared

Can you improve the supply?
  • Increase storage, organise a back-up supply
Do you have access to mains water or an alternative supply?
  • Contact Dwr Cymru Welsh Water to understand cost of connection to mains
Do you have spare tanks, bowsers or containers available?
  • Can these be filled locally, or by neighbours/ friends/ family? Don’t forget to boil water prior to use!
What measures can you take now to save water?
  • Consider harvesting/storing grey water from baths/showers/sinks in order to preserve your clean water for human consumption
Have you contacted your water engineer?

Keep your supply pumps/treatment serviced and maintained to ensure efficiency and potability



  • Private Water supplies are the responsibility of the individual home owners
  • The Water Industry Act 1991 gives local authorities, if required, the power to serve a Section 80 Notice on a relevant person(s) to take appropriate action to address actual or potential insufficiency
  • The Housing Act 2004 also requires the provision of an adequate good quality water supply for drinking and domestic purposes.


Further information

For more information, go on our website Private Water Supplies or contact the Pollution Control team on 01437 764551 or via email 

Drinking Water Inspectorate (opens in a new tab)

Public Health Wales (opens in a new tab) 

Dwr Cymru Welsh Water (opens in a new tab)  

ID: 10372, revised 09/11/2023