LAND DRAINAGE.

Otago Daily Times, Issue 20319, 30 January 1928, Page 8

LAND DRAINAGE.

EXPERIMENTS AT WETHERSTONES. EFFECT OF SLUICING. Canterbury, in common with Otago, possesses large'tracts of the most fertile land whoso surface is subject nt intervals to inundation by water becaue of its low level. The drainage of these areas is an event greatly to be desired, as the prosperity of the Dominion is first and last directly dependent upon the productivity of the S °For nearly 70 years the problem of draining the lands bordering upon Lake Ellorsmere and Lake Forsyth, in Canteroury has baffled every attempt at solution',’ and up till the present time it has been found impossible to maintain an outfall channel from those lakes to the sea. Only when the wator--lcvel m the lakes has risen to a height of 4ft above normal, and has submerged many thousands or acres of rich land has it boon possible by means of scoops, to open a channel through the barrier of shingle, thrown up by the sea between its shores and the waters of the lake. Unfortunately, the channel, when opened, is soon dosed again by the sea, and the land is again gradually submerged by the accumulating waters from the lake a period of eight months usually elapsing before the channel can be again opened to drain the water away. A few years ago a scheme to pioviae a channel by means of a tunnel trough the shingle barrier, was proposed, ultimately earned into eflcct. at a cost ot some £12,000 but the structure was, soon af”er its completion, totally destroyed by the sea, and a solution of the problem seemed as far off ever. forth Time, however, is said to b j g -. d | cu H Protein may who has had ence of hydraulic mining a u d d b eeP r n ?eat o stfd°some time ago by that a Permanent _ the .adoption zJ&ssrsrsu * ■ teTbuary toUowung was" appointed H°P°f l1 cd F Miller James Mackenzie r? n 1 \ w Ynrr (Springs County), isCounty), E. Yarr (spr and ?’ F Clfmie (organiser for the Progress i. l. uima v > inv itation of Mr brEri. sjrsg retary) m’diTslcw^ ■Rln«3 Rnur find Gabriels Oullj. • Srtv was joined at Wetherstones by Mr T E' Strachan, of Rangiora, president of p ' oc “" i.!,° .V was: S. v«nw. "'b pr ®. * duMd\? e dfrect"npT jot of water upon 1 formation of shingle or tailings. Ure natations for the demonstration had been S lw llr IV. R. Smyth, a director of the Golden Crescent Company, by airangement with Mr Stewart, a powerful nozzle having been placed in position to command a "large area of shingle com■nriserl of tailings from the mmo. P The purpose of the demonstration was to enable the members of the commission to realise the nature of the vork which could bo accomplished by the use of water under pressure in the removal of a bai rier of P shingle such as the sea built, up across the outlet from the lakes. The nozzle used in the demon Hi at on was 2*in in diameter, the jet of vale issuing under a pressure, of about 100 b per ennare inch. Before a start y<• s made Mr Stewart explained to the Motors that the demonstration which the., were about to witness showed one phase onlv of the process which he proposed should be used in connection with the drainage of the lakes, that the nozzles to be used would number at least four, all of them encased within submerged cylinders supplied with air from the ‘atmosphere. They would be placed at cer tain P intervals along the line of the outfall channel which they would excavate and maintain by the use of au^ atC The device admitting air to the cydimler. The nozzles would operate on the shingle to be removed with an effect vastly greater than the nozzle they would now see in ° P The*°visitorß having been advised to take up a position of safety at some distance behind the nozzle, the nozzleman took his place and directed the jet ol water against the shingle formation which it scattered and tore its way through with a power and rapidity which a P a rt frmn hein" would be unbelievable. The speed with which the shingle was removed and a channel cut. through the formation by ihe jet was in the mature of a revelation to those who had not previously seen a nozzle at work, the visitors being impressed by the Pnwer of the lot even at a distance ot nearly oOOft tioin the nozzle, to cut away the shingle and leave behind it a well-defined channel. 4fftor the nozzleman had given a display, showing the excavating power of the jet a number of the visitors in turn took charge of the nozzle and were amazed at the facility with which the landscape could be blown away and altered by the power under their control. After a demonstration extending tor upwards of an hour and a-half, and everyone present appeared satisfied with what they had witnessed, the party, accompanied by Messrs W. R. Smyth, J. R. Smyth, and E. Browne, directors of the Crescent Company, proceeded by car to Lawrence,.where Mr P. R. Climie, m a short speech, traversed the steps which had already been taken in connection with the movement to secure a solution of the problem which for so long had exercised the minds of the. land owners and the various, public bodies interested in the drainage of the lakes, and said that the members of the commission would return to Canterbury and present a report upon what they had that day seen done by a jet of water, and on the opinions formed in their minds as to the possibilities of the scheme which Mr Stewart proposed should be adopted to secure the end so much desired. Mr Stewart, m outlining his scheme, said that tho plant would consist of a motor driven' centrifugal or turbo pump supported on a concrete foundation on a permanent, site, and capable of supplying a jet el water similar to the one they had seen in operation. Four pipo-linces I3in in diameter would extend from the pump to tho several points where the nozzles would bo placed. The How of water through . these pipes would be controlled by a scries ol valves placed at the pump house. After a number of questions had been asked and answered, Mr J. E. Strachan (president of tho Progress League) tendered to Mr Stewart the thanks of tho commission for the opportunity afforded them of witnessing a demonstration such as the one they bad just seen at Weatherstones. Tie felt sure also that he was voicing the opinions of nil members in saying that tho effect of the demonstration 'was to leave in their minds the impression that the same process could bo used with success hi tho solution of the probiem before thorn. Messrs T. Thompson, T. Coop J. Mackenzie and S- R- Wright also spoke briefly on tho same lines. Tho party then paid a visit to Blue Spur, at the head of Gabriel’s Gully, and there saw the nozzles at work.