HARBOR BOARD MEETING.

Grey River Argus, Volume XXXI, Issue 5319, 14 October 1885, Page 2

HARBOR BOARD MEETING.

: = (Concluded). * The " following is the report ""of the Engineer on. the " LAKE BRUNNER SCHEME. *' As promised, I have now the honor to lay before you a report on the proposed scheme for utilizing the water of Lake .Brunner to scour the bar, when during periods of dry weather it silts up, owing to the low state of the Grey River. . "The object of the present report is to enable the- Board to decide whether or not a y further steps should be taken in the matter. "The scheme itself, as at present proposed, is to erect sluices at the head of the Arnold River where it leaves Lake Brunner. These sluices must be of sufficient depth and width to discharge such a quantity of water in a given time as will be sufficient to maintain the bar in good working order during periods of continued dry weather. It is also proposed if necessary and practicable to supplement the waters of the lake by diverting part of the water from the Teremakau river into the Orangipuku, one of the feeders of the lake. " The two most important points to be decided before the scheme in any form can be adopted are : — "I. Is the scheme practicable, and "IT. Will the benefit to the harbor be commensurate with the expenditure which will have to be incurred. These questions cannot be finally settled, until after the whole scheme has been carefully prepared and fully discussed, and all that can be done at present is to decide whether the probability of success is such as to justify further surveys, observations, and plans being made. These two leading points will depend upon the answers to many subsidiary questions, some of which I wiil now put and endeavor to answer. "I. What is the smallest quantity of fresh water which can be depended upon for keeping the bar open in calm weather ? j "11. What is the smallest recorded ! quantity of water coming down the Grey River after a period of dry weather ? "111. How much of that quantity comes from the Grey Valley, and how much from the Arnold 1 "IV. The whole quantity required to scour the bar, less the quantity in the Grey River ia that required to be brought from Lake Brunner : what is this quantity ? "V. Is the bed of the Arnold large enough to carry this quantity of water? "VI. Is the quantity of water which feeds Lake Brunner sufficient to supply the amount required for Bcouring in dry weather? * "VII. Can adamand sluices of sufficient capacity and of a reasonable height be made to discharge the required quantity of I water ' ' VIII. Will the costof constructing and maintaining such works, if carried out, be commensurate with the advantages to be derived from them by the port. ' ' None of these questions can be ans v/ered without careful consideration ; but I will now endeavor to reply to them, as far as the information obtained will permit me to do so. "Question I. "In reply to question I; the only (evidence I have as to the quantity of water required to act upon the bar is the result of observations made on the 17th and 18th of August last, ,

" Previous to the 17th, continued dry '< cold weather had caused the bar to silt up, and on the 17th the river was some--1 what swollen by rain and melting snow. The estimated discharge on that day was ' ' at the rate of 10,700 cubic feet per second. 1 A spit which has formed on the north side of the channel near the mouth of the river began to be affected, and it was the opinion of competent judges that the quantity of water in the river was sufficient to affect an improvement on the bar, had the weather outside been calm, which it ; was not. There was however no means of verifying this opinion by soundings or otherwise, as the flood continued, and on ; the 18th the river was still further swollen, . and fche estimated discharge amounted to 22,000 cubic feet, per second. After the [ flood had subsided the bar was found to [ have improved to the extent of 3 feet, and on the 19th there was a depth of 11 feet on the bar with 8* 3" above datum on 1 the gnage at the wharf, equivalent, to about 13 feet 9 inches on the bar at high water of spring tides. A heavy sea was running all the time, and it may be 1 presumed that, had the sea been calm, 1 the improvement would have been greater. " This one observation cannot be accepted to establish a rule, particularly • as it was only a matter of opinion that the first day's, fresh would have been sufficient to scour the bar. At the same time, some valuable information was gained and the quantity 10,700 cubic feet | j per second, acting continuously for 24 hours, may,. I think, be accepted for the ' purposes of this report as sufficient to keep the bar opened. Further observations must however be made as oftan as opportunities .occur before this question can be finally answered. " Question 11. " The river Grey was very low before the flood of the 17th and 18th of August, and the bar began to be bad on the 2nd of the same month. The estimated discharge measured . on the 10th was at the rate of 3,100 cubic feet per second, which may be accepted for the present purpose j as the ordinary low river after a continued drought. "Question 111. "No observations have as yet been i made to ascertain how much water comesj from the Grey, and how much from the i Arnold in dry weather ; but it is assumed i that one-third of the total is from the Arnold, and two-thirds from the Grey. 1 , "Question TV. "Taking . the answer to question 111 as near, enough for the present purpose, the quantity of water required to be | drawn from the Arnold, will be 10,700 — ' 2000=8,700 cubic feet per seoond, which should be continued for not less than' 24 hours, in order that it may act with effect. "Question V;: '.<" " So far as can be seen from, the portion i of the river which has ; been examined; the, i river bed, when full to t.he top of .-the l lowest observed banks, will carry 17,500 cubic feet of water per second, which i capacity could be increasedif necessary i by forming artificial banks at low parts. But 17,500 cubic feet per second is double the assumed quantity that would be required. Therefore the bed v of the Arnold river is large enough to carry the required quantity of water 7 "" " Question. .VI. "The quantity of wartfer to be drawn from the lake will be not less than 8,700 cubic feet per second, for a; period of 24 hours on"c a week, equal to 800 million 1 cubic feet each week. t! Suppose that a period of dry weather has set in, and it is required to scour the river for 24 hours, 800 million cubic feet of water will be drawn off in that time, and (the srea of the lake being 14$ square miles), the water level will fall nearly two feet. In order to insure the lake being raised to its original level before the next soouring is required, say one week after, the first scouring, 800 millions cubic feet ■ of water will have to be restored to the, > lake, besides what may be required to 1 make up for loss by evaporation and 1 leakage. 1 "In reply to question H, it was estimated that in very dry weather the Arnold ' river carries 1000 cubic feet per second, which would give not quite 605 million cubic feet in a week. But 800 millions are required ; therefore it appears that the present feeders of Lake Bruuner are not sufficient to keep up a drain of 800 million cubic feet a week during very dry weather. "On the other hand, the sluices might be made, say five feet high, so that after two feet were drawn off there would still remain three feet on the sill. The sluices now being closed, the 600 million that would come in during the week would again raise the level of the * lake one foot i six inches, and it that way it would take I about four weeks consecutive scouring to reduce the lake to that level, at which it would cease to afford the full supply required. " Question VII. "A dam and sluices of sufficient capacity could be made either at the mouth of the lake or lower down the river, as shown on the accompanying plan. In front of the water cushion below the slaices, i modulus would be placed io enable the caretaker to regulate the discharge through the sluices. " Question VTII. " The reply to this question must be de- " layed until the scheme is more developed than it is at present." " Recapitulation. " The conclusions to be drawn from the above considerations are : — "A. That a practical scheme for artificially flooding the Grey River from Lake Brunuer can be worked out either with or without the aid of the Teremakau. . ; f 'B. If water can be brought from the rTeremakau into the lake, the latter will not have to be raised so high, and consequently the cost of the works need not be | increased, and might possibly be reduced by utilising the Teremakau. It remains to be seen, however, whether a feasible scheme for diverting the Teremakau can be prepared or not. * "C. As to the quantity of water required to act beneficially oh the bar further observations will have to be made, and such observations can be made ] occasionally when the river is in a suitable state. Some time must elapse before ( [ any definite conclusion can be arrived at ] on this point, but that need not prevent ( the scheme from being worked at in the mean time. £ " D. As regards the financial benefit to be derived from works of this kind very little can be said at this stage. It would

depend upon the extent to which the average depth on the bar will be increased, and also whether such additional depth can be obtained more economically by this i or other means. "It may be argued against the scheme, that while the water is being stored up in - the lake, it is being taken from the river Grey; but a large volume acting for a* short time on the bar will have more scouring effect than the same quantity extended over a lengthened period, and if the water of th<^ Teremakau can be utilised this objection might be entirely removed. •■ " There are two falls at the upper end of the Arnold river, about two miles from the lake, and it was hoped that they might have been of great advantage in enabling the level of the lake to be lowered ; but, on examination, these were found to be only about three feet altogether, so that very little benefit will be derived from them. "Estimate; "It is not known what, if any, protective works may be required i found the margin of the lake, but it is assumed that some works of this kind may be needed. The track from Greenstone to the lake would have to be improved, boats and buildings, &c, would have to be provided for. The most expensive item will oe the construction of the dam T and 'sluices. " Allowing; for the above items, but »ot for land purchase, I estimate, roughly that the scheme would cost between £20,000 and £2s,ooo. '..' ...■'■;■: ' ' Recommendations. "In conclusion, I beg to recommend that the observations -which ■ have been commenced for ascertaining the quantity of water that will be, required be continued, and that the rivers Teremakau and Orangipuku be examined in order, to ascertain whether these rivers can be utilized. When these observations have been completed a scheme for the works can be drawn up." The report was received. : The Chairman said it would be seen from the terms of the report, that it was ef a very important character, but as it was purely a question of engineering it was not for him to pas_s_an_opinion on it ;..still -it was clear that the maintenance of a permanent workable bar was of the very utmost importance to them. He was satisfied that so far any expense that had been incurred was fully warranted by the information that had been obtained from the report of the Engineer, which was well worth the money. In the meantine he thought they could not do better than refer the matter to the Works Committee. —Mr Kerr thought the best thing they could do would be to follow out Sir Jno. Coode's plans for another year or so. r ' He had no fault to find with what Had ibeen done, or what it had cost them ; but he submitted that £25,000 was altogether too much? That was one-fourth of their oapital, and it would be a pity to waste.that on schemes not' altogether warranted, tand then be compel^: tp apply to Parliament for more moni^ortfe before they ought to be justified^jn^dping so.— Mr Guinness pointed out that there was a letter from Government reminding the Board that they had no authority to engage in such an undertaking. He suggested that it would be a good idea to get Sir Jno. Coode's opinion upon the matter.— The Chairman said that no doubt the scheme was quite outside of Sir Jno. Coode's scheme ; but nevertheless he did not think it ought to' be dropped now. Having taken the' matter in hand now, they ought to collect all the information obtainable on the matter while they were investigating. He did not of course mean that they should compromise themselves in any way. But it would be wise to submit all the information they had obtained to Sir Jno. Coode in referenoe to; i this question without going so far as to bring him over here, He was decidedly in favor of an. increased volume of water;.; from the lagoon, and perhaps after the details of the Lake Brunner scheme were made known to him he might pronounoe a favorable opinion upon it, though a cost of £25,000, according to the Engineer's estimate, was a great deal greater expense (See fourth page.)

than the Board had contemplated or were prepared for. Still, there was no dpujrtj that when the port was closed by a bad bar' the revenue of the Harbor Board was affected to the extent of hundreds of pounds. The matter was then referred to the Works Committee. The report of the Harbor Master was then read and received. The clerk then read a batch of inward correspondence on various matters.' Amongst the letters was a letter from Messrs Hungerf6rdand'"Mac'K'ay~in refer-' ence to the works they have in hand, and the amount of new plant they had procured and ordered, laiid also giving explanations why the work had hot been a more; advanced stage at present/ Thieletterwas' referred to the Works Cornmil'tee'in'con"* junction with 1 the Engineer's report. Letter from; Mr Lynch in respect to certain timber which had been rejected j and thrown on his hands after h^ng' been squared[and hauled out of the bush. He asked that the Overseer be instructed to inspect the^timber on the ground before being hauled (put of the bush.— The Chairman moved that the applidajtibti \ljej not entertained. — Mr Guinness .'moved, that 's the Overs*eer be instructed to inspect the timber on the ground as requested, provided the contractor paid the expenses of the Overseer.— Mr Sheedy took a similar view, and hoped the Board would see its way to grant |the request. ; The Ojerseer ' wou'd probably not^b'e] required to visit the ground more than once a fortnight or so. — MrKerr said the men did not call on the Board until they felt the pinch. They had lost £25.: He thought the request reasonable. Messrs M'Lean and Lahmau thought the request might well be complied with conditionally. -^—The .Chairman thought it would be a dangerous precedent to establish to pass the motion proposed by Mr Guinness. The ammendment was then put and carried. ; The Chairman; then moved as a further amendment that the matter be referred to the Works Committee to determine where the inspection should take plate, and what class of timber it should refer to. The amendment was put and lost, and the motion of Mr Guinness agreed to. „. q <J "I ff s ( An application fof/jthe, position, o'f.jcarev/ taker was received. Ordered to be considered when found necessary to make the appointment. letter was read from the Marine Department in reference to the Lake Brunner scheme, and pointing out that any work of the kind was beyqnd. ,the power' of rthe Board as at present bonsftitiited. ; I \ < The Works* Committee's report was read, and after some consideration clause one was referred back to the committee for reconsideration. The report was then adopted as amended. 1 J&. Resolved that the Executive Committee hold office for eight weeks after coming into office. , The report of the Finance Committee was read, containing a list of accounts. — Adopted. : Mr Kerr moved a resoution with the object of inducing the Board to provide suitable shed accommodation on the wharf. The mover referred briefly to the necessity, of providing increased shed accommodation. — Mr M'Lean seconded, and Mr Lahman cordially supported the reso- ... lution. — Mr Thomas said he never saw 'goods so roughly handled and thrown about in any part of the colony as they were here. There could be no doubt as to the want of increased shed accommodation, and the sooner they got it the better.— The Chairman could not see that the duty properly devolved upon the The Board or a committee shouid^decide upon the matter and assist the Engineer. Nor should the shed be alongside the present one. It would aldo & be necessary to consult with the manager ■$£oi the railway, as it ought to be their object to work in harmony with him. — The mover of the resolution accepted the suggestions of the Chairman, and it was resolved ,that a committee be appointed ,j. ■qonaistihoj of the Chairman and Messrs McLean and Kerr to indicate the directionimwhich shed extension should be made. The Chairman moved that at the next meeting of the Works Committee Mr Stalker be requested to state to the Com- '■■■ mittee the course he intends to pursue. — Mr Guinness moved that the Engineer be instructed to prepare plans for steam cranes .and hoppers with a view to facilitate the export of coal, and that application be made to the Government for authority to procure the same. — Seconded by Mr Thomas and carried. The Board then adjourned.