THE ST. CLAIR BEACH

Otago Daily Times, Issue 23970, 20 November 1939, Page 6

THE ST. CLAIR BEACH

TO THE EDITOR Sir—At a time when world affairs occupy the minds of most people mos* of their time, some of our own problems which are just as vital to us are overlooked, and when the time comes when they must of necessity be attended to it is found the time has passed for remedial measures and expensive schemes have to be adopted to save further wastage. The St. Clair sana erosion problem is a case in point, and measures must be taken immediately to prevent what must, from the present position, develop into a oroblem o major important# Thirty years ago there was only a small proportion of sand at the St. Hilda end of the beach, and lagoons were present where great mounds of sand now exist. On the other hand, there is no alteration in sand formation at the St. Clair end as far as building dp is concerned. Years ago I wrote propounding a theory which to-day is proving itself, and I ask for space to explain again. Supply and demand and reserve.' seem to be the order of the day. with

costs an ever present bogey which troubles not a few. The same condi tions can be applied to the St. Clair problem. Nature grinds slowly but very surely, and, where man has se ! out to outwit hef. he loses more often than he gains. It is well understood that the ocean current is up the coast and the supply of sand is from the south, and also that the current is sometimes very close to the shore Now, the fact that very little sand ever lodges at Second Beach at St. Ciair and that if sand does appear there it does not remain long, is well known The same applies to the extreme south end of the St Clair beach. Such action, then, must be the eddying nature of the water, due to the suction of the current oast the projecting bluffs. In the case of the St. Clair end of the beach, that eddying will extend to a considerable distance up the beach, but only the distance governed by the pull of the eddy. Each time there has been a bad loss of sand at St. Clair there has also been a big scour into the bank of sand towards St Kilda, but never past the St. Kilda tram terminus. Steep banks of sand are formed, which gradually break away to form the well-known slope which sand must take. Much of the sand thus scoured will drift back to St. Clair in the water, and will collect during calm water conditions to await another abnormal shore current condition to take it out into the current channel with the Solent eddying. Each lime, another slice of the sand mound at St. Clair has to go to make up for what should have been there by natural means. Man’s mistake has been in his would-be control of the sand drifts. As I mentioned before, the sand at the St. Kilda end is greater than it has ever been, and the trapping by lupins and marriam grass of the drifts that would supply the St. Clair end surely points to the cause. One has only to stand on the beach on a windy day to understand what an immense amount of movement goes on, but if it is trapped at given points the demand of the farthest points is not going to be satisfied. Such is the condition at the present time, and the supply and demand, not to mention the reserve problem, are still to the fore. There is only one remedy if the natural or nature method is to remain as it is, and that is, to extend the esplanade still further, until the erosion, as seen by the present dangerous condition of the sand bank, is passed: and in time such may have to be repeated, but it will only become urgent until the eddying influence towards the St. Clair end is passed. It is said you cannot break Nature’s laws: you can only violate them. —I am, etc., Keen Observer.