New silt modeling methods by Dr Graham Daborn, Acadia University Centre for Estuarine research, Nova Scotia, helps us understand just how fast mud is deposited. A Severn barrage could lead to the beaches of Wales and the South West being plastered with a living slime of mud.

Traditional models like those now being used on the Severn, treat silt in the same way as sand, a non-sticky grain. Silt however is a living thing. It is full of tiny life. These mini molluscs, bacteria and worms secrete mucus that hold the sediments together. Dr Daborn’s studies have shown that this produces deposits 80 times stronger than traditional models expect and which do not wash away. He states that, ’such accumulations would quickly fill up an estuary’.

The outdated models are being used right now to give misleading information to the company doing the feasibility study. Using incorrect modeling has lead to disasters in the past. Dr Daborn gives three examples in Canada where this has lead to barrages being constructed resulting in massive sediment deposits choking the river, leading to flooding and blocking harbours and destroying fisheries. Mud was deposited at a rate of 15cms per month. This mud now extends 11km down stream of the barrage and is still growing. On the Severn this would plaster the beaches of the SW and South Wales with a living slime of mud. The beaches would be gone.

Silt arrives in the Severn from both direction leading to choking mud downstream of a barrage and silting of the ‘head pond’ above it. Resulting in loss to the economies of coastal resorts and harbours and increased flooding above and below the barrage and loss of generating capacity.

It is time we admit the fact that the Severn Estuary is not suitable for a barrage. Research by Dr. Daborn and other experts from around the world shows it simply just would not work.

Full extract of Dr. Daborn’s barrage study can be seen here:

http://saveoursevern.org/dr-graham-daborns-report-on-silting/

Gloucestershire County Council are being lead headlong into a mire by misinformation about the proposed Severn barrage. Barry Dare, Council leader, is being misinformed and in turn is misleading people. He seems to be under the impression that a barrage would produce cheap electricity. Any electricity produced from a barrage would be very expensive. The study prepared by the National Trust and nine others NGOs released last week, states any electricity would be very expensive and would equate to bigger bills for all. Gloucester County Council should be calling on the Government to spend money earmarked for the Severn on a ‘Green Energy Zone’ - micro generation and insulation for all, encourage ‘Green Technology’ to the area, boost the regions economy and importantly provide proper flood management for Glos and Tewks. Studies have shown that a barrage would increase the chances of flooding in Glos and Tewks by reducing the rivers capacity to transport water away. It would also increase flooding down stream. Who would pay for dealing with this? A barrage is not suitable for the silty Severn and not the way to reach 15% renewables by 2020 there are cheaper better ways. Experts believe even the feasibility study is a waste of money especially as it being undertaken by one of companies proposing a barrage.