Silting and Grounding

Port Edgar Berth Holders representatives met with the Marina Manager, Fraser Sturgeon, on 10th July to discuss reasons for the grounding of several boats in approaches to their berths, and what remedial action might be taken.

Silting has always been a problem for Port Edgar. When it was a naval base, constant dredging was necessary, but this was an accepted cost. It now forms a major component of the Marina’s expenses. In addition, environmental concerns mean that dredging requires a Licence from the relevant Scottish Government agency. Acquiring this involves expensive surveying, sampling, and specialised analysis to be completed before any permission to do the work is granted. Work is underway to obtain a Licence for proposed dredging in 2018.

A new concern is the effect of the new Queensferry Crossing towers and viaducts on the movements of silt. This is under review. The Berth Holders Association will look into the possibility of promoting an academic project at Ph.D. level on silting in the Marina.

Fraser produced 2 sets of bathymetric survey charts, showing the water depths before and after dredging. It was agreed that he would have the “after” chart exhibited on the marina’s notice board on the Pier Loop Shed. It was also agreed that this was a “snapshot” of the situation on the day it was produced, and no guarantee of long term accuracy, due to the continual natural movement of the silt. It does, however show how the best approaches to berths are the channels dredged near the East and West Breakwaters.

It also shows the extent of silt surrounding the floating Tyre Breakwater, due to the way the breakwater is moved by wind and tide. A fixed breakwater would limit the area of siltage, but long term solutions are not financially feasible meantime, and short term arrangements, such as sinking old containers would have to meet strict environmental requirements. Ways of delineating these shallows were discussed. Buoys and Transits were impractical, while fixed posts would require extensive piling and demarcation.

As a result, the shallower areas South of the floating breakwater should be avoided by steering close to the ends of the pontoons.

The problem is not easily solved. Silting is a major issue for east coast harbours. The BHA and Marina management will continue to review how best all vessels can make their way to and from Marina berths at every state of the Tide.