Lorn Environmental Action Forum (LEAF) is a group of groups, whose members are a number of local groups focused on aspects of the natural environment, individuals, environmental organisations and representatives from the commercial sector, including fishermen and tour boat operators.
This is an informed, powerful and valuable collective, harvesting expertise and perspectives from the necessarily wide spectrum that leads to the most secure recommendations and muscular lobbying capacity.
At its most recent meeting, LEAF focused on the impact of a fixed link – a causeway – between Seil and Luing, as is currently proposed. Below is the substance of its report on that meeting.
The Luing-Seil Fixed Link
The idea of a fixed link is not new and there has been media speculation of late about the impacts of a causeway closing the Cuan Sound.
In 2006 the Scottish Transport Appraisal Guidance (STAG) report concluded that: ‘The causeway has been discounted because of the significant environmental effect it would have, in particular on the aquatic life of the Cuan Sound, and its effect on navigation through the Sound and the subsequent knock-on effect on the economy of the west coast of Scotland’.
The subject has been resurrected by recent reports that parts of the Cuan Sound might be shallower than charted and therefore the costs of a causeway might be expected to be less than those originally estimated.
LEAF feels that this matter needs further careful and impartial investigation, for many reasons including safety, loss of biodiversity and negative impacts on tourism and commercial sectors like fishing and aquaculture. Further scientific study is needed to predict the effects of the project on tidal flows – which evidence suggests may result in flooding and insurance related problems.
Closed Fixed Link: the worst option
The presentation and open discussion on this issue at the LEAF meeting on the 17th February ended with a vote. This returned a unanimous decision (apart from two abstentions) that a fixed link that stopped or restricted the tidal flow and prevented navigation was the worst possible outcome.
The use of a high level bridge or tunnel that did not restrict tidal flow or navigation was found to be acceptable.
Special Area of Conservation
The Firth of Lorn has been designated as a Special Area of Conservation (SAC) under the European Commission’s Habitats Directive: Natura 2000.
Rocky tidal reefs with strong tidal flows are the qualifying feature, with porpoise being found in significant numbers.
Within the Cuan Sound the SAC’s eastern limits end at the Cleit Rock – which lies at the eastern end of the Sound close to the island of Torsa.
The exceptionally strong tidal flows are vitally important to the protected ecosystem of the area – an ecosystem that supports numerous priority protected habitats and species.
Closing off this important stretch of water could have serious implications to cetaceans and other aquatic animals in general. Migrating cetaceans could become especially affected by the closure of the Cuan Sound. Salmon farms in the area use acoustic deterrent devices; these are known to have adverse effects on cetaceans including disorientation. In the event of tidal disruption by a closed fixed link cetaceans could be prevented from returning to open sea, with the risk of mass cetacean strandings increased.
While pipes allowing some flow of water might reduce the effect on the ecosystem it would not help the larger Cetaceans. Both larger fish and marine mammals can be expected to suffer. The effect on smaller animals is not well understood. Any restriction to tidal flows in this complicated region could have serious effects elsewhere.
Tidal Problems
Restrictions to the tidal flow will alter a much larger region than just the Cuan Sound. Amphidromic points are important when considering altering tidal flows. From the amphidrome near Machrahanish to The Clachan Sound, the rising tide can only pass through narrow passages between Islands. While the effect of closing one of these 6 outlets requires a full hydrographic study, there is no doubt that such action will affect the tidal flow through the Clachan sound, Sounds of Seil and Luing, the Grey Dogs, Corryvreckan, and possibly even the Sound of Islay.
The hydrography, bathymetric nature and morphology in the region is such, that blocking the Cuan Sound could be expected to result in faster flows through the other passages with potentially catastrophic knock-on effects in neighbouring areas like the Clachan Sound, Seil Sound and Balvicar.
The road at Balvicar is already subject to flooding. Numerous houses are situated close to the water’s edge and any restriction to the water flow would be exacerbated by the funnelling effect of the surrounding land, potentially making the narrow Clachan Sound treacherous or at least less suitable for moorings.
Southerly gales with low pressure systems would push up dangerously high waters causing flooding of houses, including the Balvicar store and post office. The main road could be subject to periodic flooding, cutting off the people of Luing, Easdale and Balvicar. Insurance premiums would soar.
Storm surges might be catastrophic. It has been suggested that an increase in tidal flow could undermine the foundations of the ‘Atlantic Bridge’.
The sustainability of the islands would be affected if residents sold up and businesses closed in consequence.
Safety Issues and cost implications
Changing the tidal pattern would require a completely new tidal stream survey of the Sound of Jura and Firth of Lorn. At least four Admiralty charts would have to be revised. Until this work was completed vessels of all kinds would be unable accurately to determine the effect of tide on their passage.
Already notorious sea passages such as the Dorus Mor, Gulf of Corryvreckan, Grey Dogs and Sound of Luing could become more dangerous.
All vessels are required by the Safety of life at Sea legislation (SOLAS 5) to have a bolt hole in bad weather. At present vessels heading south from Oban and the Sound of Mull can enter Cuan Sound and in 10 or 15 minutes they are in sheltered water with a choice of 8 anchorages.
The passage through the Sound of Luing would almost certainly become more hazardous than at present and add as much as 14 miles or 20 miles ( 4 Hours) for a vessel that has to tack into a storm. Some vessels would be unable to cope with the adverse conditions and some would not be able to cope with the tides.
Local fishing boats, tourist boats, aquaculture service boats, and local yachtsmen would be the most affected, along with boat owners and businesses at Balvicar Boatyard, Kilmelford and Croabh Haven.
Island Life & the Rest of Argyll
Islands and the island way of living are dramatically altered when an island is joined to the mainland. Not all of Luing residents are in favour of a fixed link. Whichever method of crossing is backed, the cost during these cash-strapped times will not be cheap.
Currently, there does not seem to be enough money to fix the terrible state of Argyll’s roads, let alone undertake vast expensive projects such as fixed links.
Many residents in Argyll will be understandably angry that £17 million (10 times the Argyll wide roads budget) should be spent apparently for the benefit of 150 voters, when it will adversely affect a much greater number of people, putting vessels and homes at risk.
Conclusions
In summary, LEAF feels that a closed fixed link should be completely ruled out because of:
- its negative environmental impacts
- problems to navigation and safety of mariners
- threat to local business
- increased risk of damage to property
- sustainability of both islands.
The photograph top is of the Clachan Sound, taken from the Clachan Bridge (or the Bridge over the Atlantic) and looking north with the Isle of Seil on the left and the mainland on the right. Informed opinion suggests that this area may be liable to flooding with the Cuan Sound closed by the proposed causeway, forcing tidal flows and storm surges through this channel. This photograph is by copyright holder Richard Knights and is reproduced here under the Creative Commons licence.
The middle photograph shows a Dolphin coming through the Cuan Sound and is by copyright holder, David Ainsley and may not be reproduced without permission.
The bottom photograph – of the almost narcissistic Common Dolphin, is by copyright holder Mark Carter and may not be reproduced without permission.
I entirely agree with LEAF’s conclusions about a causeway closing Cuan Sound being theworst option for a fixed link between Seil and Luing. I also, fail to see why a tunnel between the two islands has not been given serious consideration as this a common method of linking islands in Scandanavia and the Faroes.
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Are there any cost or engineering reasons why a low-level bridge has not been considered? Obviously this would obstruct navigation, but it would permit the tidal flow to continue as normal. Compared to a causeway it would be the lesser of two evils.
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I too entirely agree with LEAF’s conclusions. Solid causeway? Very Canute. £17 million? Oh yes? Double that at least, to keep in line with other public construction cost overruns. I can’t help thinking one could build and operate small ferries for many, many years for that amount of outlay.
Bridge? Think Skye.
Tunnel? I would have thought that to be the most expensive option, though if there has to be a fixed link, that would be the least intrusive. Not sure whether the slatey ground would be stable enough though.
Wouldn’t it be cheaper to rehouse those who don’t like living on an island?
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The reason I raised the spectre of a tunnel is the fact that, I do not, from the information I have read, that the proporsal has been studied seriously. The real advantage of a tunnel is that it will neither obstruct the tide nor be closed when the wind blows, as the Skye Bridge has and will be. I would like to see the TRUE costs of a ferry, causeway, brige tunnel published on line.
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I think you’re right. I doubt that any of the proposals have been looked at seriously. I have a feeling it’s all about the local politics of people who haven’t got enough to occupy their minds. Accurate comparison of costs of all options would be good, but I doubt we’ll ever see any. The concept of TRUTH, these days, seems alien to our public SERVANTS, those at local level taking their lead from the execrable example of our UK national government.
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