PROTECTION OF RIVER BANKS.

Wairarapa Daily Times, Volume 2, Issue 283, 7 October 1879, Page 2

PROTECTION OF RIVER BANKS.

To the Editor-of-tU Waijurapa Daily,

Sir,—l believe, at the present, more than at any previous time, public attention is being directed to the -protection of river banks, and the alarming encroachment of our rapid streams on roads and private property. This fact induces me { to draw attention to an article in the "Transactions and Proceedings of the New Zealand Institute," and Styled " Deflection of shingle bearing currents, and Protection of River Banks by Douslin'a C-s Floating Dams." The dam is cok ; structed by driving two or more piles into ■ C; the bed of the stream immediately 5.' above the point of invasion, and at an angle of 135 degrees down stream. To these are securely moored a log about two feet in diameter and as near the bed of the stream as possible; and to this is attached, by wire or chain, a succession of logs, allowing a space of about one foot between each, and sufficient in number to admit their floating on the surface of the ; •water during a flood.

The theory is as followslf a current will carry shingle when travelling at the rate of six miles per hour, when the current is reduced to half the shingle will naturally lodge at the point of obstruction, and has been known to raise a bank Bft, high in a stream 12ft. deep at a ; single flood; whereas a solidglamor groin V would probably be undermined or washed | away, and would not collect spy M of shingle. It is obvious thai this' V struction would not cost anything It much as the groins that have usually' erected for this purpose, and should jy prove as efficient here as they have ueen in the Wairau River, there is no question that they will become a lasting benefit to this country, in protecting bridges and diverting the courses of nearly all our rivers where they require it. Further particulars and a plan of the i dam can be found in the above-named A volume, of which I have a copy, andJß which I would be glad to show to anwH person desirous of trying the experimejgjißE Hoping that these remarks attention to the matter, '-ffiflH Donald DonaShß Solway House, October Gth. Imm