Geology Site Account

Hamford Water National Nature Reserve

Hamford Water is a large, shallow inlet between Walton-on-the-Naze and Dovercourt with an interesting complex of saltmarsh, sandbanks and tidal creeks. It is unusual as it is similar to an estuary but is only fed by a few small streams and not a major river as elsewhere on the Essex coast. Extensive saltmarsh covers one third of the area. There are several islands of London Clay that protrude above the level of the marsh such as Skippers Island, which is an Essex Wildlife Trust nature reserve.

The Hamford Water embayment - a depression in the London Clay bedrock “ is filled with marine sediment, and demonstrates the influence of the surrounding geological features on the estuarine processes. Normal estuaries on flat lands develop a funnel shape that is controlled by the energy of waves and tides. Hamford Water cannot do that because of the rising ground and the lack of river valleys; it is consequently short and fat. The mouth is constricted by The Naze, Horsey Island, Foulton Hall Corner and Pye Sand. Lose any one of these and the tidal energy would destroy the saltmarsh at the site. Unfortunately this is exactly what is beginning to happen and the reason could be that Pye Sand is only about a third of its original size €“ the result of marine dredging possibly as much as a century ago.

Hamford Water is internationally important for wildlife, particularly breeding birds, and most of the area is a National Nature Reserve. Much of it is privately owned and public access is restricted but it can be viewed from the sea wall footpaths.