Severn Barrage could bring floods, destroy wildlife and livelihoods
09/02/2010 12:20:14
Questions
The Oosterschelde is "the most important intertidal staging area for ducks and waders in south-west Netherlands. Thousands of geese Anser, feeding in adjacent farmland polders, use the area as roost." The barrage there doesn't seem to have effected the birds too badly?
The Oosterschelde has very different system and history the Severn. The Severn has a bore, but the Oosterschelde doesn't, which implies they have a different system. The Oosterschelde is a very different beast now to when it was in its natural state several hundred years ago, before the Dutch engineers created a series of islands, dams, dykes etc. What guarantee is there that the Severn will behave in the same way?
Oystercatchers are not especially rare in the UK, and is found across Europe, Asia, The Middle East and North Africa. Why are the Severn Estuary oystercatchers so important?
The Severn Barrage would produce 5% of the UK's power requirements. What alternative scheme would the RSPB propose?
Report - Barrage would be a disaster for the SevernFebruary 2010. Increased flooding is just one of the potential disastrous effects of a barrage across the Severn Estuary, according to the RSPB. An official Dutch report - obtained by the RSPB - details the flood risk as well as the devastating impacts for wildlife, fishing, tourism and shipping from the construction of a storm surge barrier across the Oosterschelde estuary in the 1980s.
The RSPB has learned that officials at the Department for Energy and Climate Change knew about the Dutch report in 2008, but have still not published their own report into the effects of a barrage on the tides and sediments of the Severn Estuary.
Loss of mudflats
The Dutch report found that: Increased erosion has led to the loss of mudflats along the estuary, leading to higher waves and water levels. Huge sums will have to be spent on strengthening coastal defences to protect lives and property. By 2050, the tidal flats of the Oosterschelde will have more than halved, falling from 11,000ha in 1986 to about 5,000ha in 2045 and 1,500ha by the end of the century. Salt marshes will disappear from all but the most sheltered locations by 2050.
| Less intertidal habitat will mean less shellfish and fewer birds. Oystercatcher numbers will have crashed 80 per cent by 2045 with other species "awaiting the same fate". Shipping channels will become shallower and harder to navigate. Shellfisheries will be hit because of loss of habitat for the cockles and mussels. Tourism will be hit by the loss of wildlife interest.
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Dr Mark Avery, the RSPB's Director of Conservation, said: "This report makes grim reading. It is the closest we can get to proof that a barrage across the Severn will devastate the estuary. Although smaller, the Oosterschelde is very similar to the Severn Estuary in many ways and it is being damaged beyond repair, something our Government appears to have known since 2008.
"The Dutch built their barrier to prevent deadly storms from claiming lives. Ironically, it has now led to an increased risk of flooding behind the barrier, but it could be argued they had little choice at the time. On the Severn, we do have a choice. A barrage would not be built to stop storm surges but to harness the tides and generate electricity. There are other, far less environmentally damaging ways to do that, yet Government studies to date have been fixated on barrages.
"We have long said the Government should invest in innovative schemes, which offer the potential to put the UK and UK engineering at the forefront of tidal power without the risk of floods, loss of wildlife and livelihoods. We know the Government have produced their own report on how a barrage would affect the tides and sediments of the Severn. The big questions now are what does that report say, why can't we see it?"
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1.
The Oosterschelde is "the most important intertidal staging area for ducks and waders in south-west Netherlands. Thousands of geese Anser, feeding in adjacent farmland polders, use the area as roost." The barrage there doesn't seem to have effected the birds too badly?
The tidal-range of the Oosterschelde estuary was only reduced by 10-20% as a result of the barrier, meaning there was little initial loss of inter-tidal habitat. However the result of decreased tidal-flows means that more inter-tidal area is being lost year by year. The ethos of the report is that problems are ongoing and worsening hence the predictions for bird habitat loss in the future.
The effects of a barrage in the Severn are likely to be more severe and accelerated as the initial loss of tidal range will 50%.
2.
The Oosterschelde has very different system and history the Severn. The Severn has a bore, but the Oosterschelde doesn't, which implies they have a different system. The Oosterschelde is a very different beast now to when it was in its natural state several hundred years ago, before the Dutch engineers created a series of islands, dams, dykes etc. What guarantee is there that the Severn will behave in the same way?
There are no guarantees that the Severn will behave the same way. However, the barrage at La Rance in France is often touted as a similar estuary as the Severn where tidal energy extraction is successful. This is despite the difference in scale, La Rance only being 800m wide, and the fact that the La Rance river is not silty like the Severn as the bedrock is Granite.
The Severn has more similarities with the Oosterschelde than it does with La Rance so the effects of a barrage are likely to be more similar as well.
3.
Oystercatchers are not especially rare in the UK, and is found across Europe, Asia, The Middle East and North Africa. Why are the Severn Estuary oystercatchers so important?
Oystercatchers are a good indicator species. If the hardy common species such as they are likely to suffer then you can be assured that rarer more specialised birds will be affected too.
The Severn estuary is home to many rare and threatened species...and oystercatchers!
4.
The Severn Barrage would produce 5% of the UK's power requirements. What alternative scheme would the RSPB propose?
The RSPB supports the emerging tidal-stream technologies that would not affect the tidal-range of the estuary and therefore have less affect on the ecosystems of the Severn.
Tidal-stream technology as it stands could provide a similar amount of energy if deployed throughout the UK rather than concentrating on one single estuary. Further developments in this technology could increase the potential for energy from tidal streams to exceed that produced by a barrage.
A question also has to be asked as to whether it is right to destroy the Severn estuary in order to satisfy our thirst for energy?
Posted by: Dave Butterton | 11 Feb 2010 12:14:48