THE ST. CLAIR AND OCEAN BEACH PROTECTIVE WORKS.

Otago Daily Times, Issue 11173, 23 July 1898, Page 3

THE ST. CLAIR AND OCEAN BEACH PROTECTIVE WORKS.

TO THE EDITOR.

Sir, —1 noticed in your issue of the 9th mat. that the Ocean Beach Domain Board had invited schemes from duly qualified engineers for the conoervation of the Sandhills and St. Clair Esplanade, and it struck me as extraordinary that at the meeting none of the members mentioned or alluded to the Dutch system of resisting the encroachments of the ocean by means of their world-renowned dykes. Having spent nine years of my youth on the Continent of Europe, I have several times dwelt in Holland,] and often have walked milei on the dykes when heavy gales were raging and tremendous' billows from the North Sea were dashing against those structures without' doing the slightest injury. As is well known, a great portion of Holland (appropriately called the Netherlands) is from 2ft to 3ft below sea level, yet the dykes are so ingeniously constructed that, the ocean has been kept within bounds for many centuries, aDd not only that, but by means of dykes a vast inland sea (the Zuyder Zee) is being steadily reclaim*!, and the land so reclaimed is;»o fertile and rich that its sale more than recoups the Government for the enormous expense incurred in reclamation.

The dyke is simply an earthwork . broad enough on top to carry a fair-sized dray road,' the sides, seaward and landward, having « batter, or slope, of 65 degrees, I ,thinfe, the seaward face being coveted with huge mats' of closelyrplaited straw securely pegged down. This protection ia in French called "le ravelement"; .'and it is marvellous to watch the angry seas rushing half way up the dyke and - retreating without looseniog a spadeful of earth. On the land side a deep ditch exists to receive tbe drainage of the lands, which is being constantly pumped up and discharged over the protected sea face into the ocean by innumerable windmills erected at regular intervals all along the top. of the dykef. '

Now, Sir, is it not feasible that a dyke similarly constructed would stop tbe encroachment of the ocean at St. Clair and the Sandhills ? In fact, the embankment would uot be so difficult or expensive, for in Holland there is no back ground to build against; while at St. Clair the land is of a greater elevation from sea level, and the dyke, would need but the one slope— i.e., the one facing the ocean. In lieu of -straw as a revelement I suggest that mattagowrie, titri, or manuka, scrub be used, umtta-; gowrie in preference; the scrub to be made up iv bundles or faggots, and laid on the face of the slops the time way. as thatch is put on a a barn, hut, or hayrick, eacb bundle to be secured to its neighbour by wire, and -when the onrushing wave, .',laden with Band, dashed against the scrub, the latter, .through the sand lodged within it, becomes as solid as possible. The wire would prevent me scrub from being lifted, and when once properly loaded with land and shingle nothing will move it. Any old' goldminer, like myself, who has bad experience in { erect-. ingt wing-dams in rivers nnd creeks, and in' building dams and reservoirs for storage of water, knows that any of the former, if built of s* one or sods, are not to be depended on in. floods, whereas those built of scrub ' never badge. The greater the volume of water pouring over them, and consequently silting them up with sand, the stronger they become; in fact they cannot be torn asunder ! again ! ..■■ I think the gentlemen forming the Domain Board have made a mistake in- limiting the various schemes to be laid before them to professional engineers only. lam sure there aw.a good few diggers of the early sixties,yet alive in Otago who have engineered and constructed vast works in the shape of water races 20 and 30 miles in length through most difficult country, built.their own! reservoirs," Sec.', without ever thinking of consulting a professional engineer, and have made splendid jobs of them too. 1 also know [of one gigantic race in Central Otago, cut in the early days, which cost about £30,000, rendered useless through the levels being wrongly taken by a professional engineer.—l am, &c, Lewis Habeis. " Quartz Reef Point, Upper Clutha, July 19.