CONSTRUCTION OE RAILWAYS.

D.-No. 6a.

25

HAWKE'S BAY. No. 55. His Honor J. D. Ormond to the Hon. W. Gisboene. Sib,— Napier, 18th October, 1870. I have the honor to transmit a report by Mr. Weber, accompanied by plans giving some description of the lines available for railway lines from Napier to the Seventy-Mile Bush. The first portion of Air. AVeber's report gives information respecting two lines from Napier to Paki Paki through the Ahuriri Plains. lam of opinion that it is desirable Air. Weber should survey both these hues sufficiently to enable an estimate of their relative cost to be made. From Paki Paki to the Seventy-Mile Bush, three lines are open, and here again I think Air. Weber should make a running survey of each, in order that the relative difficulties and advantages may be more definitely ascertained than can be done from the information at preseut available. I have, &c, The Hon. Alinister for Public Works, AVellington. J. D. Oemond.

Enclosure in No. 55. Mr. Weber to His Honor J. D. Ormond. Sie, — Napier, 17th October, 1870. In compliance with your instructions, I have collected during the last week, information respecting the most practicable lines for a railway between Napier and the Manawatu Bush, prior to actual survey of the trial lines. As I have the advantage from my long connection with the Engineer and Survey Department, of being pretty well acquainted with the features of this Province, it was not necessary for me to go over the whole ground, and I have confined my field-work to the taking of soundings across the Ahuriri Lake or Inner Harbour, and of running levels over the low flats subject to floods bordering on the Ahuriri Lake, so as to be able to select the least expensive and least exposed line. I have been materially assisted by the plan showing the levels taken by Mr. Eochfort, of the Ahuriri Plains, a tracing of which plan I have the honor to enclose, with the two trial lines projiosed across the Ahuriri Plains. I likewise enclose a lithographic plan of the Province of Hawke's Bay, showing the three lines practicable from the Ahuriri Plains to the Euataniwha Plains. In starting from Napier, which practically consists of two distinct places, viz., Napier proper aud Port Ahuriri, which are about one mile and a half apart, and separated by a limestone island which cannot be crossed by a railway without considerable expense, lines of very different character are obtainable from the two starting points. I have called the two lines A and B on the enclosed tracing. Line A, from Port Ahuriri, runs for 100 chains over the Ahuriri Lake, with average depth at high water of 4 feet, varying from 2 feet 6 inches to 5 feet 6 inches, and soft mud bottom of about 5 feet, below which there is (as far as ascertained) everywhere very good holding-ground for piles —of stiff blue clay. A timber viaduct on piles, 3 feet above high water, would be quite safe, the current being neither very strong, nor does it carry large and heavy timber in floods. Thence the line runs for two and a half miles over land (partly under tidal influence) subject to floods from the Tutaekuri, requiring embankments from 1 to 4^ feet, broken at several places by open timber viaducts so as to allow escape of storm water. The material for the embankments would probably have to come from the Bluff at Napier. The next 125 chains run over sound level ground without obstruction. Then the Tutaekuri will have to be crossed by a bridge of about 300 feet long. A pile bridge of 20-feet span stands well about one mile and a half below this place. The bridge will strike the low land on the proper right bank of the river, much subject to the overflow of the river, wdiich breaks heavily over its right bank below Pawhakairo, flooding our line for a distance of about one mile. To allow of the escape of the storm water, which has carried heavy timber during the high floods in May, 1867, at least 30 chains of the line should be carried on timber viaducts, the remainder on embankments from 1 to 3 feet high, for which good soil is obtainable at the upper end. The next 50 chains to the Tutaekuri AVaimata run over level sound ground. From the Tutaekuri AVaimata, which can be spanned by a bridge about 86 feet in length, the land is again subject to being flooded for a distance of about two and a half miles. This portion offers iu my opinion rather serious difficulties, and will be rather costly as the storm water is caused by the overflow of the Ngaruroro by the AVaitio (as shown on the tracing), which overflow has rapidly increased within the last few years, and which will continue to increase, the fall in that direction being considerably greater in proportion than by the present river-bed, which has been filled up for a considerable distance with shingle above the head of the Waitio. In fact it appears very probable that the bulk of the Ngaruroro water will come that w ray. Any works undertaken here will have to be planned with that view, and about one mile of the two and a half miles shown as flooded should be constructed as open tJmber viaducts to provide for the storm waters, which have considerable power, but do not carry any timber.