Hamford Water is a 2,185.8-hectare (5,401-acre) biological Site of Special Scientific Interest between Walton-on-the-Naze and Harwich in Essex.

It is described by Natural England as "of international importance for breeding little terns and wintering dark-bellied brent geese, wildfowl and waders, and of national importance for many other bird species."

Rare plants include hog's fennel and slender hare's-ear.

[6] Two small areas, Skippers Island and John Weston Nature Reserve, are managed by the Essex Wildlife Trust.

[7][8] Most of Bramble Island (now part of the mainland) is used by Exchem for explosives testing.