The Guardian And Evening Star, with which is incorporated the West Coast Times. FRIDAY, JUNE 15, 1928. RIVER PROTECTION.

Hokitika Guardian, 15 June 1928, Page 2

The Guardian And Evening Star, with which is incorporated the West Coast Times. FRIDAY, JUNE 15, 1928. RIVER PROTECTION.

Theiie was a general debate by members of the Westland County Council on Tuesday afternoon relative to methods of river protection. The inroads made by coastal rivers are proverbial, due of course in the main to the fact that the streams are short and swift. The mountain range is about 20 miles distant on an average from the coast, and with the store of snow practically all the year round, and the high average rainfall, there is a largo volume of water to find its way to the sea. Probably the Hoods in themselves would not be so devastating were it not for tho quantity of debris brought down. SlipK in the high country provide large quantities of silt as well as forest growth, and this latter class of mater-

ial causes considerable damage in itself. However, the effect of the cause arising from recurring floods is all too apparent, ft is not possible to check the floods, for the water will find room for itself. The efforts are directed, therefore, to save river bank erosion. Uircumstances vary in almost every case, due to the velocity of the stream and its ability to bring down debris. There is to be taken into account also the class of country the flooded river attacks. The river Hats, so called, have, as often as not, )>ecn made by the river, and the theory is that just as the river made, so will it unmake. Itiver beds in the main are rising steadily due to the amount of light debris carried a distance and then settling down. Rivers are assisted often in their eroding effects by floating timber which becomes stranded and causes currents to deflect. These instances suggest certain methods for river protection, and so all kinds of wing work have been devised. Opinions have been divided and changing as to the angle these structures should he laid. Placed with the current was once tho regular method ; next at right angles to the bank, and finally upstream. The erections at right angles or up stream cause the greatest Ixiil . and consequent change in the river, and perhaps it was for this reason at the County meeting this week opinions we re expressed in favour of . down stream piling following the contour of the hank. By sheathing the piles a retaining wall would he provided, bellind which scrub and stones could be placed to constitute a firm backing. When methods of this, or in fact, any nature are considered, the question of cost naturally comes up. There can hardly be a cheap form of river protection, but even costly work may he undone by a single flood. From time to time even bridges, well and truly built, are carried away by the vagaries of a flood, and protecting walls often fail to defy a stream when in record flood. It is no doubt difficult, in fact impossible, to deviso any simple . method to give assured success in protecting a threatened river bank. Local bodies and others studying any given situation, must be guided by local circumstances and conditions, and the whole is governed by the cost involved. One essential, we should say, is that what* | ever work is put in, it should not he

left to take care of itself, and be expected to stand indefinitely. Any and all protection work should be the subject of constant attention. It should be effectively maintained and any change should be countered without delay. All too often the tendency is to allow matters to drift, but we are inclined to think that in regard to river protection work the stitch in time counts specially. The whole subject is of great- interest to this Coast, for up -and down Westland are many localities where serious danger is menaced. A closer study of the question is essential, and with the experience already gained in several localities, it should l>e possible to improve matters in regard to the more effective control of streams menacing the general welfare of any locality.