A word of caution is in order, to temper the general enthusiasm of those who stand to benefit:
The proposed scheme for the artificial reef shows the situation at various states of the tide. If you do the sums, you will realise that the proposal is for 50 thousand tonnes of estuarine sand and gravel to be deposited in Newquay Bay, just below the low water mark of Great Western and Tolcarne beaches. This material to be contained in bags with a lifetime of only 25 years. It sounds like a long time, but, believe me, its not. Will the bags withstand the winter storms of the North Atlantic for 25 years? Will they withstand even a vandal armed with a Stanley knife? What will be their ultimate fate?
Whilst the credentials of the engineers involved are impressive, we should be concerned that conditions in Newquay are very different from Narrowneck on Australia’s Gold Coast (not Sydney, thanks for the correction RW). First of all, the tidal range in Newquay is of the order of 25 feet. That is a lot of water. So we have to consider two distinctly different situations:
Low water – waves carry a lot of water towards the beach. This usually escapes sideways, making its way back out to sea at intervals along the beach, forming rip currents. On a smooth beach, these tidal rips are in a state of constant change, and are not permanent features. With a fixed reef however, there will be strong rip currents either side of the shoreward ends of the reef. Because the reef’s position is fixed, these will gradually erode the sand away to form a pair of deep channels, or until bare rock or boulders are exposed.
High water – the nice little animation on the reef Web site shows smooth water, with a fishing boat harvesting the oceans bounty. What happens to the waves? Answer, they do not roll straight in towards the shore as before, but are ‘bent’ inwards as they pass over the reef, and interfere with each other where they meet. If the reef is positioned as proposed, then the beaches at Great Western and Tolcarne will never again be suitable for holidaymakers to bathe in, and enjoy the rolling waves that brought them there in the past. It will either be a maelstrom of intersecting waves apart from a couple of hours either side of low water, when there will instead be a flat lagoon bordered by deep channels and permanent rip currents.
The important decisions concerning the reef should not be dominated by those who stand to benefit the most commercially. This is probably one of those few occasions where it is important to let the people decide. Now, I am not an oceanographer by trade, so my concerns may be unjustified, but the consequences of getting it wrong would be with Newquay for decades. Lets hope that the feasibility study funds have been spent on addressing the technical concerns, and not just on a pretty Web site and an analysis of the benefits to big business.
One positive alternative might be a smaller scale reef, on a trial basis, that could be removed if the effects on the environment proved damaging. The other change would be to site the reef between Tolcarne and Lusty Glaze, where there are cliffs on the shoreward side of the reef, and not a popular holiday beach.
I should make it clear that these are my personal views, and that provided the technical issues can be satisfactorily dealt with, I believe that this reef would indeed bring in the revitalisation of Newquay that it so badly needs, and together with the Eden Project and Rick Stein’s efforts in Padstow, substantially reverse the economic decline we have seen in Cornwall during the past 20 years or so.
John Baxendale CEng CPhys MIED