On 19 March 2026 His Majesty King Charles III declared the Seven Sisters National Nature Reserve (SSNNR). It is the first National Nature Reserve in the King’s Series to be designated for the protection of groundwater. The launch was the culmination of years of work and research carried out by South East Water and our partners to better-understand the relationship between our groundwater resources and the landscape above it.
The Seven Sisters National Nature Reserve is located on the chalk hills of the South Downs around Seaford and Eastbourne and forms part of the Sussex Heritage Coast, which is globally renowned for the white chalk cliffs of the Seven Sisters. It covers 1,500 hectares of land, of which South East Water owns 250 hectares. Groundwater provides around 70% of the drinking water supplied by South East Water which makes the landscape above our groundwater aquifers critically important.
South East Water-owned land within the SSNNR is made up of woodland and rare habitats such as chalk heathland and chalk grassland and includes Lullington Heath and Friston Forest, which was planted partly to protect water supplies. As a company, we have been managing our land in a way that supports biodiversity and our groundwater resources for decades.
Our research at these sites, which we carried out with Natural England, inspired the creation of the SSNNR. We found that the way land is managed above an aquifer can affect both the quality and quantity of the water it holds. This means that by having a mosaic of habitats managed at the right locations in the landscape we can maximise ground water quality and quantity, providing essential services to the local community as well as contributing to climate change resilience.
Early findings suggest that restoring chalk grassland and heathland may support both biodiversity and water resources, while woodland can play an important role in protecting water quality. As climate pressures grow, understanding these relationships becomes increasingly important.
Designating the area as a super National Nature Reserve will enable us to work in partnership with local stakeholders to protect local habitats, the chalk geology and in turn, the drinking water resource. To do this we will work with local landowners and farmers to use regenerative farming practices and nature-based solutions to provide these vital services for people living, working and visiting this part of the South Downs.