VALLEY PORT

Evening Post, Volume CXXXVIII, Issue 77, 28 September 1944, Page 8

VALLEY PORT

OPPOSED BY CITY

THREAT TO WATER SUPPLY

"It is considered that the construction of a port at the mouth of the Hutt River to accommodate overseas shipping would constitute a grave danger to the maintenance of the artesian system—at least if the construction of port facilities were attempted by orthodox means," said the Deputy City Engineer of Wellington (Mr. E. R. McKillop) in evidence given to the Hutt Harbour Commission today. ■■;:■■., Mr. McKillop said that, except for isolated pockets, the water-bearing strata throughout the Valley appeared to be inter-connected, so that a major disruption affecting the uppermost stratum would affect the whole of the underground supply. • To provide berthage for overseas shipping a depth of water of not less than 35 feet would be required, so that the overburden on the artesian strata would be so reduced, in thickness as to endanger the whole system of artesian supply. If wharfage was to be established by orthodox methods extensive piling would require to be driven into, and possibly through, the remaining cover of material: there was no guarantee at all that that could, be accomplished without considerable disturbance to and disruption of the reduced sealing layer. • . * PREVIOUS EXPERIENCES. Mr. McKillop said that in July, 1929, bores were put down at Point Howard by the Wellington Harbour Board prior to the construction of the wharf there. One bore penetrated the sealing layer and resulted in an up-cur-rent of artesian water of such a velocity that the diver was unable for some time to approach the hole. In • January, 1937, the Government cmi ployed two -draglines for reclamation at Scabey Island operating in the Hutt River where it was proposed to construct the overseas berthage. The cut made by one of the draglines reached a depth of 60 feet below low water, and marked reductions in I artesian flows followed. Pressure loss was noted throughout the Valley and some users were completely robbed of water. The pressure drop, was restored by the re-filling of the, hole with excavated "material and with, material brought down by the river in flood. , . "At this stage no one can say what the Hutt harbour will cost to build and equip, but one can fairly assume that it will be in the neighbourhood of a million pounds. The interest and sink- ; ing fund charges on this would be about £50,000 per annum. Assuming that there is- a margin of Is a ton from revenue over and above working expenses available to meet capital charges, one million tons of cargo would be needed per annum to meet these charges. The Hutt harbour would probably not have more than -213,000 tons of cargo per annum, and a large financial deficiency seems certain." Mr. Norman also discussed costs and savings in haulage if cargo were to arrive over wharves at the Hutt instead of by road cartage from Wellington wharves. The Government Town Planner (Mr. Mawson) had inferred that there would be a saving of 10s a ton, but Mr. Norman maintained that that would not be the real position. The schedule cartage rate sfrom Wellington wharves to Petone and Lower Hutt was 10s a ton, but that charge would take the goods into the store or warehouse of the Hutt trader. If wharves were erected at the Hutt the goods would then have to be loaded into lorries and carted into the store or warehouse, for which the schedule rate was 4s a ton for the first mile and Is additional for each subsequent mile. The saving in cartage would, therefore, only, be about half that inferred in Mr. Mawson's report. In addition, the saving would be offset by higher wharfage charges at the Hutt, the additional cost of moving ships about, and additional cost of segregating cargoes.