Groundwater in Wales: what it is and how to protect it

Groundwater is the water stored in soil and rocks underground that are known as aquifers. It is a critical and often forgotten part of the water cycle. Groundwater is a vital resource, sustaining our springs, rivers, and wetlands, providing habitats for lots of species.

It can be abstracted for drinking water or for use by industry and farms by using boreholes with pumps. Groundwater currently supplies about 5% of the public water supply in Wales but in rural areas, groundwater may be the only viable water source for isolated properties.

We’re seeing an increased use of groundwater heat pumps which recover the heat stored naturally in groundwater to heat homes and businesses. These systems can make an important contribution as we try and reduce our reliance on fossil fuels for heating.

Protect groundwater from pollution

There are simple steps you can take to protect groundwater:

if you have a heating oil tank, make sure you check it for signs of leaks
make sure your sewage treatment system is being maintained and is registered with us
store and dispose of chemicals properly, don’t pour them onto the ground or into drains
make sure you use water efficiently around the house and garden
report pollution incidents or suspected illegal abstractions

Guidance on preventing groundwater pollution

Find detailed guidance on:

We have adopted the Environment Agency’s approach to protecting groundwater. This sets out:

our aims and objectives for groundwater
our approach to its management and protection
our position and approach to the application of relevant legislation
the tools we use to do our work
technical guidance for groundwater specialists

Theis information is mainly for developers, planners, environmental permit applicants and holders, abstractors, operators whose activities affect groundwater.

Our staff use this guidance to make decisions on the planning and environmental permitting applications we receive.

The main aim is to prevent groundwater pollution and protect groundwater as a resource.

Risks to groundwater

Groundwater is vulnerable to pollution, and once polluted it can be difficult and expensive to clean up. We aim to prevent damage to groundwater in the first place rather than having to restore it later.

Common groundwater pollution risks in Wales:

agricultural activities such as inappropriate spreading of material to land and slurry spills
leaks from domestic heating oil tanks
poorly operating sewage treatments systems

Groundwater also risks being over-used in many areas, where more water is abstracted from aquifers than is recharged by rain. We use our abstraction licensing policies to manage abstraction in Wales to prevent this from happening.

Climate change will affect groundwater in Wales. We’re expecting more intense periods of rainfall, concentrated over a smaller period during the year. This means some of our aquifers won’t be able to fill up as well as they do now, and we are likely to see an increase in groundwater supplies such as springs drying up.

Monitoring groundwater in Wales

We maintain a network of sites across Wales where we monitor the quality and level of groundwater.

Groundwater quality data shows us the current state of groundwater in Wales and lets us see where it may be being polluted by surrounding land uses. We also use it to look for new types of contaminants
Groundwater level data helps to tell us how much water is available in our aquifers and allows us to understand where a change in climate or abstraction patterns may be having an effect.

Permits for discharging to groundwater

Find out if you need a permit to discharge to groundwater

Get more information

You can get advice on managing groundwater risks through our discretionary advice services:

To access any of the data, maps or reports we hold on groundwater in Wales please visit our Access our data, maps and reports page.

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