Tag Archives: River Defences

Deben Sea Walls, Salt Marshes, Cuttings and Tides

Posted on by

Editors Note

One of the most striking exhibits at the Waldringfield Tidelines exhibition in August 2025 was a set of posters produced by Bob Crawley and summarising his research into the Deben sea walls. Although Bob admits that the work has raised more questions than it has answered — and therefore his findings are provisional — the beautifully presented posters will certainly open many people’s eyes to a feature we too easily take for granted. 

  • Poster 1 asks When and Where were the Sea Walls Built?
  • Poster 2 discusses The Tide Level Problem
  • Poster 3 offers a Salt Marshes and Sea Walls Briefing 
  • Poster 4 explains Dating Sea Walls by Salt Marsh Elevation
  • Poster 5 focusses on Sea Walls Near Waldringfield
  • Poster 5a Sea Walls in the Deben Estuary
  • Poster 6 explores Waldringfield’s Mystery Cuttings

There are references and suggestions for further reading. 

By Bob Crawley

This began in early 2025 as a survey of the relationship of clay levels to sea walls, but developed into a wider investigation of the Deben sea walls. Along the way, interesting findings were made. The work has raised more questions than it has answered, so findings are provisional. The results were presented as a slide presentation below or as set of posters for an exhibition held in August 2025, attached <here>.

[Show picture list]

Bob Crawley

With a background in Computing and Communications technology, Bob Crawley relocated from London to Suffolk in 1987. Being near the North Sea led to wreck diving on the East Coast and other water sports. Later, living in Waldringfield triggered a belated enthusiasm for yacht sailing. This fitted neatly with an interest in the history of our local waters and estuaries, especially the Deben.

Flood Defence of the Estuary.  Are we facing a catastrophe?

Posted on by

By Robin Whittle

Several articles have been written in the Deben Magazine concerning the river wall defences1,2,3,4.  This article concentrates on the immediate need for action on the river wall of Flood Cell 1: Bawdsey to Ramsholt.

The clay river walls of the River Deben have provided landowners and the local community with grazing marsh and arable land for the past five hundred years.  During this time the walls have been raised by about 0.6m/century to compensate for sea level rise and clay wall settlement (see Figure 1).

Figure 1:  River wall at Ramsholt being enhanced in 2015

Where breaching occurs, the wall is either eroded down to saltmarsh level or, where there is no saltmarsh, down to the embanked fresh-water marsh level.  The latter is very difficult and extremely costly to repair, usually requiring the use of helicopters.  Overtopping is not necessarily damaging to a wall providing the wall is largely level and the overtopping is less than 200mm over a landward slope of not less than 1:2. (see Figure 2).

Continue reading →

Maintenance of the River Wall to Flood Cell 01 on the River Deben

Posted on by

By Robin Whittle

Introduction.  This article describes an investigation concerning the maintenance of the river wall to Flood Cell 01.  This has led to an understanding of how the raising of any river wall in the estuary will affect the possible flooding of other flood cells.  The work has resulted in providing the landowners with the results and a proposal for a protocol for the maintenance of the river walls.

Figure 1 (taken from the Deben Estuary Plan, 20151) shows the topography of the flood cells.


Figure 1: Topography of the flood cells

Continue reading →