DE-WATERING THE WHIROKINO.

Manawatu Herald, Volume LII, Issue 4579, 14 March 1931, Page 2

DE-WATERING THE WHIROKINO.

LOCATION OF PROPOSED FLOODGATES. A DEBATABLE POINT. At Thursday’s meeting of the Moutoa Drainage Board Mr. F. C. Hay (engineer to Ihe MannwatnOroua River Board), waited on the Board on behalf of Air. A. K. Speijs and lodged a protest against (he erection of the proposed floodgates at Dnefk Creek, Mr. Hay said that from an engineering point of view the Board would not he doing the best thing by erecting the gates at Duck Creek. The most effectual place to put the gates would be on Mr. S. Easton’s properly further up stream from Duck Creek, because for one thing at that site the. cost would be less. More scooping would certainly be necessary for the intake, bat there would be far less work in obtaining a good outlet and foundation tor the gates. A good foundation was most necessary and be would be very surprised if Duck Creek would afford as good a foundation.as the river (bank. Maintenance costs at the Easton site would be much less ns there would be less channel maintenance. It would also have the advantage of being able to discharge Mood wafers at a greater rate as the distance the gates would tie from tin- river would bo not more than one and n-half chains while at Duck Creek the distance would be much greater with only a small channel to carry the water. Until Duck Creek channel was widened to the full width of the gates (titi ft.) it would be impossible to discharge the water properly. He did not know whether the Board had made provision Tor widening the channel in its estimates or whether it was intended to leave the channel to lx* scoured out. If no tirovision had boon made to widen the channel the cost of the scheme would be increased considerably. There was no doubt that, the river bank site was by far the cheaper pro posit ion. TIME THE ESSENCE OF TIIE CONTRACT. The chairman said that as far a.- thi' Board was concerned time was the essence of the contract. If it decided to alter the location of die gates Mr. Easton would have to be given forty days’ notice that the Board intended to take the necessary land. Mr. Easton strongly objected to the gates being constructed on bis property as he considered Duck Creek the natural outlet. He also pointed out that if the gates were erected on his property they would meet the full force of the westerly gales whereas Duck Creek outlet was sheltered from the prevailing- wind. If we abandon DUck Creek site, said the chairman, the scheme is gone for this season. EFFECT OF PREVAILIN'!; WIND. Mr. \V. Carter asked Mr. Hay what the effect of the wind would In on the gates at the different sites. Mr. flay considered that the wind would be no more detrimental at the Easton site than it was at the Main Drain site. Mr. Carter was of the opinion that the wind was detrimental to the working of the Main Drain gates. Mr. Hay stated that in any case (he clfei-l was negligible and even it it was it could he overcome by mechanical means. If the wind makes a difference equivalent to the pressure on t he doors' of an inch of water at Main Drain I will be much surprised, said Mr. Hay. In any case, he continued, the water at Duck Creek: will he more affected by Ihe wind even if the gates are less exposed, and the wafer was the governing factor. A QUESTION OF FALL. Mr. Carter asked if the fall was as good at the Easton site. Mr. Hay: Yes. At Duck Creek the fall might be greater, lie said, but that would be compensated for by a shorter channel at the Easton site. PROPERTY OWNER’S OBJECTION. The chairman asked if Mr. Spoil's’ objection to the proposal was owing to the fact that his Mood baulk would he right up against the outlet when constructed and whether he would lie satisfied if the -bank was shifted back. Mr. Hay said that was only one objection. Mr. Spoil's contended the erection of the gates would have a detrimental effect on his property; there would be a danger of his stop bank being eroded; Duck Creek outlet bad turned almost back on to the river and was now discharging up-stream and to make an efficient outlet a (itift. wide channel would have to be cut with the result that he would have (itift. of water between him and 11 acres of his properly; and that he would I'eeeive more flood water than he would be entitled to, thus imposing hardship. The chairman pointed out that the Duck ICreek gates would act only as auxiliary gates to the Alain Drain which carried the bulk of the water. Mr. Hay: There would be a flflft. outlet at Duck Creek nevertheless. Mr. B. G. Gower said that as things were at present the flood waters ran straight over Mr Spears’ acretion land and was in no way confined to the channel of Duck Creek. POSITION WITH REGARD TO SPILLWAY. The chairman asked Air. Hay how the Easton site would be effected by the Alunawatu-Ovoua River Board’s proposed spillway. Air. Hay said that when the river cuts were made the gates would

not be required. At the Easton site the gates would be in the centre of (lie spillway and would therefore prove very efficient in the discharge of drainage waters until the river scheme was completed. At Duck Creekl they would lie useless as there would be a bank between the gates and the spillway. SILTING TROUBLE. AIV. AVI E. Earlier referred to the silting that had occurred at the Main Drain floodgates and considered that there would be a risk of silting at the Easton site. Air. Hay said there would be no fear of silting at either Easton’s or Duck Creek. The gates would be for the purpose of discharging the top floodwaters at a big head and not under water. Air. Gower considered that spring tides and small floods would cause silt to form in front of the gates at Easton’s site.