THE SILTING PROBLEM.

New Zealand Herald, Volume XLVII, Issue 14336, 5 April 1910, Page 7

THE SILTING PROBLEM.

REVIVED BY THE FLOODS.

MINING VERSUS FARMING.

V • . CLAIMS OF EACH SIDE.

As a result of last week's floods farmers on the lower reaches of the Ohincmuri Rivethave seized the opportunity of renewing the agitation, concerning the silling up of the river by the deposit therein of mining tailings. They revive their old and debatable contention that, instead of washing out to sea, the silt is left on wayside agricultural land, with detriment*! results to grass and crops, besides forming obstructions in tho waterway, which they say have reduced the scope, of navigation and lessened the capacity of the river to accommodate, flood waters. This question, however, has another aspect.

By those interested in the mining industry the farming community is said to he making " a mountain cut- of a molehill. ' The obvious point is made that Hoods occur in rivers in which no tailings are deposited, such as the Waikato, and that they would occur with equal frequency in the Ohinemuri River if no tailings were deposited therein. Farmers' estimates of damage are also said to be absurdly high. Again, it is contended thr.t the extensive plantation of willows aly.ag the. winding river is largely responsible" for affecting the channel.

WHAT THE FARMERS SAY. Mr. Wm.. Moore, a Xetherton. farmer, who claims to have been a heavy loser, informed a. Herald representative, that the floods were driving settlers away from Xetherton. His son, he said, had booked his passage to Canada to take up land there. A number of thrifty miners and bush workers who took up land on deferred payment about 18 months ago were also likely to leave the district. The silt,' he declared, was obstructing the channel at many points. " Why," Mr. Moore remarked, " there is an island in the mouth of the Waihou River 16ft higher than water level that has been formed entirely by tailings. Again, some years, ago the steamer Enterprise took a vice-regal party right up to Paeroa, and at that time scows used to run that far to». Now the Northern Company's boats can only find waterway to tho Puke Wharf, some miles by river below Paeroa. If the silting continues we expect to see the river service gradually recede from Paeroa."

ESTIMATES OF DAMAGE. Many acres in the agricultural and pastoral belt, which extends from below Karangahake to the districts , embracing Puke Road and Netherton, have been left with deposits of silt, and the banks of the fine yellow sand which have formed at several points of the river present in some measure the appearance of .sea beaches. Farmers contend that the silt forms a hard crust over the soil, which checks the growth of grass, crops, fruit, and vegetables.

As. an instance of the assessments which have been placed by farmers upon their losses, that given by Mr. Frank Moore, in connection with the 1907 flood, totals £1051 10s, and is made up of the following items of alleged damage: — acres oats, £144 12. acres meadow hay, £72 183 acres grass land totally destroyed, £457 10s. loss on creamery cheque through want of food, £225; loss on pigs, £63; "feed required for five months, £60 ; cattle drowned in flood, £30. Several such estimates of damage are being prepared for the Royal Commission of inquiry.

Less than a fortnight ago Messrs. Buchanan, Moore, Tatley and Lochlin took soundings opposite Te Rahgiora, and at points above and below that spot, with a view to furnishing the Silting Association with 'information which will be placed before the Commission. ' ■ • AN- ENGINEER'S STATEMENT.

"There is not the slightest doubt that under the present '• methods of treatment the tailings are reduced to such very fine sand as to ; enable them to float out to sea," said Mr. S.Fraser, chief engineer of the .Waihi Gold Mining Company's battery at. Waikino. "Of the thousand tons which are treated each day at the works, 70 per cent.," he continued, "are now reduced to absolute slime, which naturally runs away with the river. The remaining 30 per cent, is fine sand. , The only solution of the problem is fine grindin", but, of course, even without the depositing of silt, floods would occur all the same. To show that rollings are not the sole trouble, it may be mentioned that thousands of tons of pumice have come down' the Waihou River, in a- few hours from the Matamata country, where no tailings are deposited." . ) Asked if he accepted the statement that the silt from the Ohinemuri destroyed agricultural growth, Mr. Fraser replied that- he certainly did not, and remarked that when the Hon. Jas. McGowan was Minister for Mines samples of the silt deposits were sent to Ruakura for testing purposes, with the result that it was proclaimed to rather improve than to detrimentally affect the productivity of the soil. "The suggestion to stack tailings is altogether impracticable," Mr. Fraser remarked. "In the first place, a special railway line would have to.be built, and the whole, plan of the company's works wouTd be affected. We have put clown a plant here costing anything up. to aquarter of a million sterling, and tho farming community seems to entirely lose sight of the groat lift that they have derived from the mining industry. Bills for supplies of goods, and coal received here from Pa'eroa have amounted at times to £1600 a month."