Saturday, 19 April 2008

Broads Society response to flooding plan

Below is the Broads Society's statement in full on Natural England's proposals to abandon coastal defences and allow the Upper Thurne and its broads to be flooded by the sea.

An online petition on Prime Minister Gordon Brown's 10 Downing Street website now numbers more than 1300 signatures. Click here to join them.

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The Broads Society has been extremely concerned to learn that three of the four options for dealing with coastal erosion being considered by Natural England would, if adopted, lead to 16,000 acres of land around the River Thurne becoming an embayment of the North Sea. It also has considerable reservations about the remaining option under discussion.

Instead, the Society is outlining a fifth option, calling for:

- the Government to provide the Environment Agency with the funding it needs to fulfil its commitment to continue feeding the beach in front of the sea wall between Eccles and Winterton, with sand and shingle

- the Environment Agency to commission a wide-ranging study into ways in which the sea wall there can be strengthened, or otherwise protected, thus ensuring that it remains in a sustainable condition for much longer than is deemed possible at the moment.

Martin George, a committee member of the Society, said: "The area that would be lost under three of the four proposals is an integral part of the Broads, a region that has been afforded the status of a national park, and the Society considers it completely unacceptable to allow part of it to become an open estuary. He continued: "If any of these three proposals were adopted, it would result in:

-The loss of several hundred residential properties.

-The destruction of Hickling Broad, Horsey Mere - a National Trust-owned broad - Heigham Sound and Martham North and South Broads.

-The loss of several thousand acres of farm land, at a time of the growing world-wide food shortages.

-The destruction of valuable and fragile plant and animal life, including: reed and saw-sedge fen, the habitat of the Bittern, Bearded Tit, Marsh Harrier, Swallowtail butterfly no fewer than nine species of moth listed in the Red Data Books as being nationally rare, vulnerable or endangered.

The other option under consideration would involve the creation of a new line of sea defences to the rear of the existing seawall and sand dunes and would minimise the amount of land and property which would have to be surrendered to the sea, as well as safeguard Hickling Broad. This national nature reserve is the largest open water in the region and is much used for tourism and recreation.

But although this option has obvious socio-economic and ecological advantages, the Society has many reservations about it, not least the likelihood that it would prove to be both extremely costly, and intrusive visually in such an open landscape.

In this respect, the Society considers it unfortunate that in drawing up its report, Natural England seems to have made the assumption that it will not be practicable to continue to maintain the integrity of the existing line of defences between Eccles and Winterton.

The Society does not accept that this is necessarily the case.

Dr George added: "We believe that it could well prove less expensive to provide the sea wall which currently fronts this section of coast with additional protection against the scouring effects of the sea than to construct a completely new line of defences to the rear.

We believe that this issue needs to be subject to a full-scale investigation. Such a study should also include an examination of the role currently being played by the nine offshore reefs which were constructed in the vicinity of Sea Palling some 15 to 20 years ago.

We are aware of studies which have demonstrated that the sand spits ('tombolos') which have developed behind these reefs are now shutting off the supply of sediment to the coast to the south, and thus increasing the vulnerabilty of the sea wall between Eccles and Winterton to two of the known effects of Climate Change i.e. rising sea levels and an increase in the storminess of the North Sea."


Ends

NOTES FOR EDITORS

Background:-

The Thurne Catchment, an integral part of the Broads, is currently protected by a sea wall which was constructed after the 1953 floods; the wall is backed by a line of sand dunes. The steel piles supporting the wall are founded in the clay underlying the beach. It is important that this clay remains covered by beach material (i.e. sand and shingle) since it is very soft, and subject to rapid erosion if exposed to wave and/or tidal action. If this was allowed to continue, the clay around the piles would be washed away, thus allowing sea water to get under the wall, and at the same time subjecting the latter to stresses which it is not designed to withstand. If this situation was allowed to continue, there is a real risk of the section of wall in question collapsing. In these circumstances, the dunes behind would be subject to rapid erosion, and ultimately washed away.

Beach material is always subject to some movement as a result of the effects of waves and tides, and in the section of coast between Happisburgh and Winterton, it would seem that its susceptibility to being washed away is being affected by a gradual steepening of the beach profile, an increase in the storminess of the North Sea, and a gradual rise in the level of the sea relative to that of the land. All three of these factors appear to be linked to the phenomenon of Climate Change.

To make good the losses of beach material fronting the sea wall, the Environment Agency has over the past ten years or so been using sand and gravel dredged from offshore to replace the missing material. However, the perceived wisdom at the moment is that this may not be practicable after about 2050 as a consequence of the continued steepening of the beach.

The Natural England seminar on Feb. 18:-

This seminar was convened by Natural England (NE) to consider how the ecology and landscape of the Broads might be affected by Climate Change, and what steps could be taken to mitigate the likely effects of this phenomenon. In addition to NE staff, those present included personnel from the Broads Authority, Environment Agency, the Broads Internal Drainage Board, Norfolk CC, the RSPB, and the Norfolk and Suffolk Wildlife Trusts. A report setting out NE's preliminary views on the subject was pre-circulated to those participating at the seminar. This document was sub-divided into two sections, the first dealing with the main part of the Broads (i.e. the valleys of the Bure, Ant, Yare and Waveney) while the other dealt with the Thurne Catchment. This Press Notice and the Notes for Editors is solely concerned with the latter.

Rather surprisingly given the controversial nature of the report's contents, it was not marked confidential. In the circumstances, it was leaked by an unknown person or organisation to Eastern Counties Newspapers, who summarised it in an article published in the EDP on March the 28th. Since then there has been a public furore, the main controversy resulting from the fact that very few of the hundreds of people living in the Thurne Catchment, were aware of the options under consideration at the seminar. These were, in brief:-

Option 1. Do nothing. Let nature take its course. Accept that one or more sections of the sea wall between Eccles and Winterton wold be breached as a result of neglect, thus converting the entire Catchment into an embayment of the North Sea.

Option 2. Hold the line. Maintain the sea wall, but accept that increasing quantities of sea water would sooner or later find its way underneath it, and that it would, as a consequence, ultimately collapse. This option, too, would result in the entire catchment developing into an embayment of the sea. In addition, it should be noted that both options 1 and 2 would result in sea water finding its way into the main part of the Broads via the Rivers Thurne and Ant.

Option 3. Adapt the line. Re-align the coast over time by allowing inundation to occur in some places, and building one or more barriers/embankments to limit tidal incursion in others. In practice, this would mean creating a new sea wall, or earthen bank a few hundred metres to the rear of the existing dunes. It is impossible to predict exactly where such a line of defences would be created, nor whether it could be discontinuous, or built in the form of a more or less continuous line between Eccles and Winterton.

Option 4. Retreated defence. The entire Thurne Catchment, including Hickling and Martham Broads, and Horsey Mere, becomes a c.16,000 acre embayment of the sea. Before this was allowed to happen, dams would have to be built at Potter Heigham and between Catfield and Stalham to prevent sea water from the embayment finding its way into the rest of Broadland.

Finally, it is essential to bear in mind that no one has suggested that any of these options be adopted until it becomes apparent that the existing sea wall cannot be maintained any longer in the face of the effects of Climate Change.

The Broads Society:-

The Broads Society was founded in 1956, and is dedicated to the protection and enhancement of all aspects of Broadland - navigation, recreation and the environment. We were closely involved in the discussions leading up to the formation of the Broads Authority, the statutory body responsible for the management of the region, and as a voluntary body with a membership of some 1600, we have worked tirelessly over the years to safeguard the interests of those who visit the region, or live and work in it.

1 comment:

imajaz said...

Just read this article

http://www.sandandgravel.com/news/article.asp?v1=10895

incredible, they can dredge the North sea to help create a new harbour for Great Yarmouth, so why can't they do the same to build a coastal defence?

If they dredged enough out, maybe the sea would not rise so much :)