Silting Commission.

New Zealand Graphic, Volume XLV, Issue 7, 17 August 1910, Page 6

Silting Commission.

COMPREHENSIVE RECOMMENDATIONS—COMPENSATION FOR DAMAGE—SUGGESTED REMEDIES.

THE report of the Commissioners, Messrs. W. Ferguson, E. Mitrlielson, R. Vickerman, and F. R. Flatman, appointed to inquire into the silting up of the Ohineinuri and Waihou Rivers was presented to the House of Representatives last week. The Commission was appointed to inquire: “(1) Whether any and what lands are injnriwusly affected by the operation of the Proclamation, of 1895, pre I.timing the Ohineinuri and Waihou rivers sludge channels; (2) whether the navigation of the said rivers is impeded from the same cause; (3) what remedial measures can be adopted without injury to any other corporations or interests; (4) what proportion of such measures should be a charge against the gold duty; (5) generally, to report on all matters arising out of the promises.” The report is a voluminous (locument of thirty closely printed pages of foolscap. Damage Done. Tiie Commission was satisfied that material damage had been done to lands in tiie township of Paeron, and to farming land adjacent to the banks of the Waihou and Ohinemuri rivers and the Komata Creek, and that this damage was directly due to tin* dt posit of mining silt and slimes under the san. tion of the Proclamation. About 550,000 tons annually was now being discharged into the upper roaches of the Ohineinuri. At first the tailings were coarse, but with the gradual adoption of tube-mills during the past six years the tailings were now ground to a slime. The Commission were .satisfied that they were justified in recommending th.it grinding to slimes be made compulsory. Slimes. The evidence, continues the report, tends to prove that slimes will not deposit to any serious extent in any current \\ here the velocity does not fall below half a foot per second, or, say, one-third of a mile per hour. As in noranal conditions the velocity of the Ohinemuri and Lower Waihou exceeds that speed, it appears to be tolerably certain that the finely ground slimes are now, and have been for some years past, carried out to sea. The evidence on this point is confirmed by the Commissioners’ Mr. Dillon: Oh! Oh! Mr. Poland: Ah! the member for Hawke’s Bay does not like that. He is one of the few large squatters we have in the Hou-e. If I were in his shoes, 1 would be satisfied, and would not say: “Oh! Oh!” Mr. Dillon comes from a district where 21 landowners hold two million acres between them. That is nearly equivalent to the remaining total area in the hands of the Maoris. Jf I had my way, I would make such a substantial increase in the graduated tax that the*e Hawke's Bay squatters would have to jump out. (Daughter and applause.) For Women and Children. At a meeting of the Society for the Health of Women and Children in Dunedin a letter was re rived from Mrs Harris, conveying an offer by Mr Wolf Harris. to give the society the premises and estate at Anderson's Bay, constituting the Karitane baby hospital, and to effect improvements in connection with the grounds ami buildings. The letter continues: “In making this offer it is assumed that the primary intention of the society that the institution should serve as a practical leaching centre for n»t* tris bearing on the welfare of mother and child, will be not merely maintained, but will hr extended and fuither systematised. It is also hoped that the hospital will always be conducted in the simple, homely way which tho society had immediately in view when the institution at Pay was founded, nml in accordance with the rules ami recommendations that the society have wince passed, as to the class of cases to be regarded as eligible for admission.’* It. was decided to heartily thank the lunor for his handsome gift.

own observations on the material in suspension in the river- waters, and by the absence to any serious extent of deposits of slimes, except in spots where, through the existence of willows or from other reasons, comparatively slack water exists. The substitution of the finely-ground slimes for the coarse .sands has brought with it the evil that now the flood-waters are heavily charged with a fine muddy material, which is washed over the whole area of the lands flooded, and is deposited on, and clings like a white wash to, the grasses and vegetation; whereas when the grinding wa.s of a coarser character the tailings were deposited to a much greater thickness, but over a more limited area of land, being dropped as soon as the flood waters lost the velocity needed to carry the heavy sands forward, which they did shortly after topping the riverbanks. The farmers find that the line slimes adhere to the leaves; that if the Hood is followed by sunshine the grasses wither rapidly; and that, even if the flood is followed by rains, the slimes are not fully washed off the vegetation. The result has been that following each flood in recent years the cattle refuse to eat the pasturage, and if compelled to do so the cows in milk rapidly fall off and go dry, re.su 1 ting in a considerable reduction in the dairy returns; and in rome eases the farmers have been left without pasturage for their cattle, and have, after floods, had to sell their stock at a loss. Young cattle, it was alleged, lost their lives through eating slimecovered grass. Land Areas Affected. A schedule of the lands affected was made by Mr C. R. Bellingham, and the Commission was satisfied that it might be assumed to be approximately correct. In the Waihou Survey District, blocks VII., \ 111., XL, XIL, and XVI. were affected, and in the Ohinemuri Survey District blocks IX. and XIII. were affected, the total area concerned being 9,976 acres, of which 371 were totally destroyed, and 7,507 deleteriously affected. The commissioners recommend an official survey of the damaged area. Compassionate Compensation. The Commissioners are given to understand that legally the owners and occupiers of land who have been injuriously and permanently affected by the deposit of mining tailings thereon have no claim whatever on the State for compensation; but they are of opinion that, apart from the legal aspect, there Is every reason why some compensation should be granted for the permanent damage done to the lands. The. landowners at the time of the Proclamation in 1895 could not have foreseen its widereaching and disastrous effect. Even had the farmers possessed sufficient prescience to have then estimated the possible (‘fleets of the Proclamation, it is fairly certain that they could not have persuaded any Compensation Court that the results which have followed its issue would have occurred, and would not have obtained any compensation commensurate to the loss that has been suffered. River-dredging Required. The Commissioners are also satisfied that dredging is now, or will shortly bo, required in the reaches of the river from the 'Pe Puke wharf down to llikutaia, a distance of some ten miles. Throughout this distance tailings are showing freely on. the banks, ami to a slight extent in the bed, of the river. Remedies. With regard to the remedial measure in Clause 3 of the reference, we recommend that the urse of the rivers as sludge-chan-nels should be restricted in future as set out herein, ami that the rivers be cleared from all growth of willows, be dredged and stop banks formed, with culverts amt flood gates where required, and that the course of the rivers be shortened by river diversions. Also, we recommend that the high-lying lands of the watersheds. whore they have been denuded of trees for mining or other purposes, should be reafforested. Disposal of Tailings. The question as to whether it would be

possible to dispose in future of the mining tailings in some other method than by permitting them to be east into the rivers has met with very serious consideration, and your Commissioners have reluctantly arrived at the conclusion that the adoption of any one or more of the schemes suggested would not be in the interests of the Dominion, as involving such an increased cost in the production of the gold as might, and probably would react in the direction of preventing the mining of low-grade ores, which at present are capable of being worked at a small profit, but only in conjunction with ore of a higher grade. The position, so far as the adoption of any scheme of disposal of tailings other than by the rivers, is somewhat complicated by the fact that the reductionworks are not concentrated in one district. There exist at present, and working, two at Waihi township, one at AVaikino. two at Karangabake, in the valley of the Ohinemuri, and one upon the Komata Creek. There are also other batteries in the district which it is understood are not at present in operation. Revoking Proclamation. Your Commissioners therefore advise that the mining industry be permitted to still discharge the tailings into the River Ohinemuri under amended conditions, and that the proclamation should be revoked and a fresh one issued under the authority of an Act of Parliament, so that no application for compensation can be made thereunder. It is advised that after a period of six months, which ought to be ample time in which the necessary additions to the plant ean be made to the mills, it should be illegal for any gold reduction works or other mining project to discharge into

the River Oliinemuri any material that has not been ground in tube mills or Other appliances approved by the Department of Mines to a fineness sufficient that 95 per cent of the whole shall be (Capable of passing through an 80-mesh standard screen. Effect of Slimes on Rivers. It is believed that vvhen the rivers are freed from willow growth and are brought by dredging, cleaning and shortening, as recommended herein, to a eonidition of moderately good discharge, the fine slimes and tailings discharged from iWaikino under the conditions of grinding recommended will at times of ordinary flow probably pass out to the sea in a period of about 50 hours. Repeal of Proclamation. The Commissioners recommend that the proclamation making the Waihou and its tributaries, other than the Ohinemuri and Komata, a watercourse for the reception of mining debris, tailings and slimes, should be repealed, except in so far as existing mines are now using them; that if any other mines in its watershed should desire to utilise the river or its tributaries, permission be specially given, after careful investigation and on special conditions, particularly as to line grinding. Stop-Banks. The Commission recommends that wherever the river banks of the Lower and Upper Waihou as far as Te Aroha, and the river banks of the Lower Ohinemuri, and of all tributary creeks to those rivers, are at any point below a level of 4ft above the level of the highest-known flood, then there should be made artificial stop-banks, having a crest level of not less than 4ft above that of such highest-known flood. New Steamer Landing. These proposed diversions in the Waihou will'."necessitate that the steamers now trading to Te Puke should terminate their run at a new wharf to be built just below the site of the present Netherton Ferry, at an increased carting distance from Paeroa of half a mile. It is (suggested that the bridge, which it is understood is about to be erected across the Waihou just below the Junction, should be erected on the site of the present Te Puke-Netherton Ferry ; and that on the western side of the new cut a road he made out of the material to be excavated from the cuts and forming the stop-bank for that portion of the river. Suction Dredge. For the purpose of construction of the Ngararahi-Opukeko cuts, and the erection of stop-banks, and for the dredging of the beds of the rivers, the Commissioners recommend that there should be purchased two suction dredges, each capable of lifting 500 tons of sand per hour. Ring-Barking Willows. The Commission recommends that the willows on the river-banks be ring-barked and treated so as to be killed; that all the branches and twigs be thoroughly removed and disposed of; that, at any rate, for the first few years, the stumps of the willow-trees be left in the soil, fco as to assist in retaining the banks and to prevent denudation; and that al! roots, stumps, brandies, and twigs of willows lie thoroughly removed from the bed of all the rivers and tributaries. Execution of Works, The Commissioners are satisfied that there is at present no capable body existing in the district to whom could be safely intrusted the duty of carrying out promptly, and in a proper and intelligent manner, the works of dredging, of forming river-diversions, of erecting stopbanks, with their culverts, and floodgates, of cutting down and removing of willows, and generally of enforcing their yeeommenda lions. The Commissioners therefore recommend that the works should be carried out as speedily as possible by the Public Works Department. Proposed New River Board. On completion the works should be handed over to a new local body specially constituted for the purpose of the maintenance of the completed works, or of the CKCeution of any additional works which

time may show to be necessary. The Commission recommends that the new Board should consist of eleven members, and be constituted as follows:—Two members to be nominated by the Ohinemuri County Council; one member to be nominated by the Thames County Council; one member to be nominated by the Piako County Council; two members to be nominated by the mining companies; three members to he nominated by the Government; two members'to be elected by the ratepayers of the new river district. Revenue of Board. The Commission recommends that three-sixths of the annual revenue required to be found by the new River Board should be deducted from the gold duty; that one-sixth should be contributed by those mines and extraction companies which discharge their tailings into the rivers or watercourses, and that the allocation of this .special rate should be directly proportional to the tonnage of tailings so discharged; that one-sixth should be derived from rates to be levied in the new river district upon all lands, native or European, excepting Crown lands, and to be leviable in varying proportions dependent on the direct or indirect benefits to be obtained, as is provided for under the River Boards Act; that one-sixth should be contributed by the Dominion out of a special allocation to be authorised by Parliament, in order to provide a contribution in respect to the Crown lands which, whilst benefiting under the proposals, could not otherwise* be rated. Wailii Borough and Gold Duty. The Commissioners find that since the Waihi borough was formed in 1902 it has received up till the 31st March last from the gold duty and goldfields revenue the large sum of £122,151; that for the year ended the 31st March, 1909, there was received from gold duty £20,775, from other sources of goldfields revenue £1553, or, together, £22,328; also that for the corresponding period ending the 31st March, 1910, the similar receipts were £22,153, and that, in addition to these large sums, there were subsidies received from the Government in 1908-9 amounting to some £395. The Commissioners are satisfied that the existence of tlie annual income from the gold duty and goldfields revenue has led to municipal extravagance, and that the . taxation by rates is far le.ss than in other New Zealand towns of a similar size. In 1908-9 the total rates collected from a population estimated as about 5850 was only some £B3O (which included £176 Government subsidy on the rates), benig about 2/10 per head of population per annum, or 119 per ratepayer. Annual Espenditure. Whilst the Commissioners have not been enabled to make estimates in great detail, they have satisfied themselves that the works' they recommend, including payment of the compassionate allowances for damage by Hoods, and including the plant necessary to execute the works, can be carried out probably for £130,000. But, in order that there may be sufficient funds, they recommend that provision should be made for a Government loan to the now Board of the sum of £150,000, which it is presumed can be provided at a rate of 4| per cent to cover interest and the extinction of the loan. Charge Per Ton of Ore on Mines. Upon the present output of about 550,000 tons of ore treated per annum, the proposed charge amounts to less than |d. per ton— a tax which cannot affect the working of any low-grade ore, and an amount which, it is believed, the mining industry can well afford to contribute towards a solution of the cliflicul ty. The Commissioners think that the fishing industry at the Thames, as relating to the llauraki Gulf, has not been seriously affected by the discharge of tailings into the river.