SES Water supplies water to approximately 707,000 people in east Surrey, and parts of West Sussex, west Kent and south London. Our supply area is 322 square miles (835 sq km) extending from Morden and South Croydon in the north to Gatwick Airport in the south and from Cobham, Leatherhead and Dorking in the west to Edenbridge and Bough Beech in the east. Groundwater supplies provide 85 per cent of our water, with 15 per cent being extracted from one reservoir at Bough Beech near Edenbridge.