Catchment Management

HomeCatchment Management

Catchment Management

85% of our water supply comes from the deep aquifers in the chalk of the North Downs or the large deposits of greensand south of the Downs. The other 15% comes from the River Eden and is stored in our Bough Beech reservoir in Kent, prior to treatment. Every year, between September and April, we abstract water from the River Eden into Bough Beech reservoir where it is stored before going through the treatment process to ensure the drinking water complies with the standards set by the Water Supply (water quality) Regulations. We work hard to manage our water and its quality and continually look to improve catchment management within our area.


What is Catchment Management?

Catchment Management aims to prevent the pollution of our rivers, streams and aquifers at the source rather than relying on ‘end of pipe’ solutions, such as more water treatment processes. Catchment Management is also a more sustainable and cost-effective way of tackling water pollution, as well as delivering on other environmental and community benefits.

‘Catchment area’ is used to describe the area where rainfall naturally collects and feeds into the source.  Our surface water catchment, known as the Eden catchment, covers 220km2 with agriculture being the primary land use which has an impact on our surface water reservoir (Bough Beech).

One of the biggest water quality challenges is from metaldehyde (the active ingredient in slug pellets). To tackle this, we liaise and meet with local farmers and agronomists to promote the use of an alternative product and are currently looking into additional measures that could help reduce pesticide and nutrient concentrations in the catchment.


Groundwater catchments

Groundwater catchments are known as Source Protection Zones. With 85% of our water coming from groundwater, using the Environment Agencies Groundwater Source Protection Zones (SPZ) we analyse surrounding land uses, such as industrial, residential and agricultural to identify potential risks. 

One of our biggest challenges with groundwater is nitrates from both rural and urban sources e.g. septic tanks, fertiliser application and sewers.




Our commitment

We have a commitment to actively engage in the catchment as a means of improving the quality of water used as a drinking water source in our area. This minimises the need for additional treatment which is also a key element of the EU’s Water Framework Directive.

To ensure we meet our commitment, we:

  • Take regular samples from strategic points throughout the catchments to give us a greater understanding of the water movements and pollution pathways
  • Work closely with others, including land owners, farmers, National Farmers Union, Natural England, Environment Agency, Rivers Trusts and Wildlife Trusts, to raise awareness of and confront the challenges we face. Click here if you are interested in working with us to improve water quality
  • Identify ‘high risk’ areas of pollution and where we should focus our efforts using GIS mapping techniques
  • Investigate, identify and address as many sources of pollution as we can
  • Support our area's catchment partnerships


Information for farmers in our catchment area

It’s important for us to work closely with farmers within our catchment area to help protect our water quality by raising awareness of the issue of nitrates and pesticides in water.

Find out more about:

Help us to continue producing high quality drinking water and protect it for years to come.

You can also sign up to our annual newsletter. To receive a digital copy email



How can you improve water quality in your area?

Get involved! 

We donated funds to Kent Wildlife Trust in 2016 to help kick start a citizen science project on the River Eden to map and monitor sections of the river and its tributaries. Once trained, volunteers record details such the river flow, colour of the water, any visible signs of pollution or pipes discharging into the river, steepness of the banks, and the vegetation on banks and surrounding area. These ‘feet on the ground’ provide invaluable information which is used to characterise the catchment and help identify issues or areas of high pollution risk.

For more information and details on how to volunteer please visit Kent Wildlife Trust's website or email



Contact us

For more information please contact the Catchment Team on 01737 785631 or email

Latest news and updates

Metaldehyde ban overturned 

2019 Eden Newsletter

In June 2018 we signed up to the catchment declaration alongside 80+ organisations. Read more here