The Grey River Argus THURSDAY, February 24, 1949. THE WEST COAST RIVERS

Grey River Argus, 24 February 1949, Page 4

The Grey River Argus THURSDAY, February 24, 1949. THE WEST COAST RIVERS

YESTERDAY’S extensive flood- ” ing along the West Coast, coinciding as it did with the meeting of the Westland Catchment Board, illustrated once again that the province presents one of the greatest problems of erosion in the whole Dominion. It is one indeed the responsibility for coping with which is unenviable in the case either of the local authority or of its engineer. The vast flow of water from the high ranges located closely to the coast line has a more fapid current than the flow in nearly every other province, and the quantity of material moved when such flooding occurs is probably so vast as not to be calculable from the data yet available on the provision made for observation. Ln such circumstances, it is quite reasonable to judge that the best criterion is that of the experience of people who have been obliged by their occupations to take serious note of the vagaries of our short, precipitious West Cdast streams. The contention was yesterday advanced by a member of ‘the Board that, so far at anyrate. stopbanks had not proven a permanent means of resisting such great currents, and experience goes at least to suggest that this contention is justified. On the other hand, streams have been undoubtedly diverted in an appreciable degree by such expedients, but when these are of the cheap type their utility is limited, and a very severe flood is apt 1o render them of little or no lasting effect. The Catchment Board is constrained no doubt by the fact that it has to work within financial resources which are insignificant in comparison to the amount of work requiring to be done if real and lasting control of erosion is to be achieved. Nevertheless it is not. sound economy to rely much upon mere patch work, nor could it be reckoned a course that would commend itself .to people whose land was at stake when they are expected to make contributions. It is, of course, notorious how radically and frequently West Coast rivers alter their courses, so much so, in fact, that the predictability of such changes is beyond , engineering experts to perhaps a greater extent than it: is beyond the foresight of others with lengthy experience and sustained observation of the vagaries of a stream to guide them. The Board, as remarked, has a great deal of

work in prospect, and naturally is disposed to make 'ds resources go as far as possible in covering the needs of the situation. If, however, there is question of doing any particular job properly, or several jobs temporarily, it might finally be more economical when doing any one to do it well. The Board must always count upon the probability of some rise in riverbeds, with the consequence ol' divergencies of the current. Locally it was once more demonstrated

yesterday that the river has a tremendous force, as also that th'? very stout—and very costly—protective works on this side have constituted a job thoroughly well done. Few if any other streams, however, have their flood waters contracted by such a fortunate natural channel as that constituted by the adjacent gorge, hi South Westland the river erosion is exceptionally great, but hitherto sparse settlement and the lack of a soil conservation policy have, seen comparatively little done to cope with this problem. It is only within the past decade that it has been tackled as a whole, but if settlement is to become closer, it is obvious that an effective technique must be gradually attained. Apart from settlers, - the subject used previously io Tie, regarded in a haphazard fashion, and engineer-

ing skill is now' taxed with the task of adumbrating a comprehensive policy. In this task, as suggested, the available data includes the experience of people familiar with the past behaviour of rivers, and that knowledge deserves to lie sifted and collated. The holders of land have a duty to co-operate, and they also would have justification for seeking from the State such assistance financially as the special circumstances of the West Coast certainly call tor. Other provinces with much less erosion than this are always eager to seek special provision on occasion.