89

35

VIII.

TO-DAY AND TO-MORROW?

There is one phase of this question that I must not altogether ignore, though it will be impossible in a general sketch of this kind to treat it in full detail. I refer to the effects produced upon river and harbour navigation by the floods which result from the clearing away of the bush. New Zealand is not, of course, the only country in which this evil has manifested itself. If we turn to America we find an imposing mass of evidence already collected under this head. In an article entitled "A Continent Despoiled" Mr R. Cronau shows how at least a billion tons of soil are swept away every year from American hillsides into the rivers and harbour mouths, not only robbing the country, but depositing the silt and spoil where it does permanent and irreparable harm. "Year in, year out, our Government spends millions upon millions to dredge river channels and harbours that become clogged with gravel, snags, and mud, deposited there by the floods." In almost the same terms, Mr. M. G. Seckendorff, in an article on "The Elimination of Waste," in a recent issue of "Munsey's Magazine," drew attention to the appaling waste of money that is one of the indirect effects of soil-erosion. "The soil-matter annually carried into lower rivers and harbours," he tells us, "is computed at 780,000,000 tons. Soil-wash reduces by ten or twenty per cent the productivity of upland farms and increases channel-cutting and bar-building on the rivers. The annual loss to the farms alone is fully 500,000,000 dollars"; and he proceeds to point out that the fertile soil thus irretrievably lost to the country involves it people in still heavier loss when, accumulated in rivers and harbours, it compels them to remove it at enormous expense.

THE COST OF SILT.

And in New Zealand, as I have already indicated, needless and burdensome sacrifices are constantly entaile upon us all by similar couses producing like effects. Everybody who has lived near the mouth of any of our rivers knows what a bar is, and how seriously it impedes navigation and trade. The silting up of our bar-harbours and the blocking of river-mouths along our coasts have already cost this country untold wealth, and the evil is steadily intensifying itself with the progressive destruction of the bush. It would, indeed, be interesting to get a return of all ependiture incurred in the Wellington-Taranaki district alone in the attempt to dredge and keep open the Patea and the Wanganui and other streams. And within a short time some systematic attempt to cope with this danger will become absolutely imperative. I can hardly sum up this portion of my argument better than by quoting from an article on this supbject which appeared some time ago in the Wellington "Evening Post." The writer deals first with the silting evil in general terms. "In all parts of the Wairarapa, and, indeed, throughout New Zealand, farmers and local bodies are faced with the trouble of the silting up of the river beds. Gravel and debris are brought down the streams in flood time. The lifting up of the river-beds forces the streams to deviate all over the country by their own natural law. The result is that in the progress of years a river covers an area miles in width. But this erosion process is not by any means the worst of the story; and he goes on to refer to the destructive effect of the depositon of silt at the river