Part 18 (1/2)
[Ill.u.s.tration: GYMPIE: SCOTTISH GYMPIE GOLD MINE]
[Ill.u.s.tration: GYMPIE: No. 1 NORTH ORIENTAL AND GLANMIRE]
CHAPTER V.
OUR a.s.sET IN ARTESIAN WATER.
Erroneous Judgment of Western Queensland.--Scarcity of Surface Water.--Water Supply Department.--Discovery of Artesian Water in New South Wales.--Prospecting in Queensland.--Difficulties Experienced by Early Borers.--First Artesian Flowing Bore.
--Dr. Jack's First Estimate of Artesian Area.--Revised Figures.
--Number of Bores and Estimated Flow.--Area Capable of being Irrigated with Artesian Water.--Cost of Boring.--Value of Artesian Water.--Extent of Intake Beds.--Waste of Water.
--Necessity for Government Control of Wells.--Value of Water for Irrigation, Consumption, and Motive Power.--Artesian Water a Great National a.s.set.
Fifty years ago the white population of Australia, including Tasmania, scarcely exceeded a million persons. At that time the theory was generally accepted that only a fringe of the coast south of the tropic of Capricorn would be found habitable by a British or European population. The reports of explorers led to the conclusion that the vast inland area of our continent was an irreclaimable arid desert, save when, at long and uncertain intervals, it was ravaged by destructive floods, the water from which, licked up by a fiery sun or absorbed by a porous subsoil, disappeared from the surface with marvellous rapidity. A little more than forty years ago squatting occupation had been pushed towards the interior of the continent with not only rapid strides, but it was held by many explorers with a presumptuous boldness that could only be followed by disaster. So deeply had this conviction been driven into the minds of experienced men that a distinguished Australian explorer, the late Sir A. C.
Gregory, declared in his late maturity, little more than ten years ago, that on what is now some of the richest and most productive country in Western Queensland a bandicoot could not live; and on the statement being challenged he said he spoke from personal experience as an explorer after two visits separated by an interval of nine years. The country more particularly so condemned was the well-known pastoral run, Wellshot, a little to the south of Longreach, and one of the largest and finest wool-growing properties in Australia.
It must be frankly conceded that the occupation by flocks and herds nearly forty years ago of what was then known as the Barcoo and Thomson country was venturesome to the point of recklessness. Except in the sandy beds of these rivers there was practically no surface water of a permanent nature; and the average rainfall was so inadequate, not to mention its capriciousness, and the ground in many places so porous, that any attempt to provide artificial water by the construction of dams or tanks seemed almost tempting Providence. Yet there arose a persistent belief, afterwards more than justified, that underneath the arid surface was flowing water in great abundance. The rainfall, however copious in exceptional seasons, certainly did not reach the sea, and the hypothesis that great subterranean rivers would disclose themselves to a systematic search attracted much notice. In the dry year of 1883 the necessity of an improved water supply if the country was not to be denuded of stock forced itself upon the attention of our leading public men. The Premier, the late Sir Thomas McIlwraith, decided to const.i.tute a Government Hydraulic Department with a competent engineer at its head. There had previously been so-called hydraulic engineers, but their work was chiefly confined to the water supply of a few towns and of the more settled districts on the coast. But Sir Thomas McIlwraith, as a runholder in the Far West, realised that nothing but heroic efforts, a.s.sisted by the Government, would save the country from desertion, with appalling loss to its adventurous occupiers and their flocks and herds. Mr. J. Baillie Henderson was at the time in the Queensland public service, and the Premier knew that he had served with distinction as an engineer in the Water Supply Department of Victoria. That gentleman was therefore selected to organise a Water Supply Department in Queensland, and on 1st February, 1883, he was gazetted Hydraulic Engineer, an appointment which he has ever since held with credit to himself and advantage to the country.[a]
At that time the existence of artesian water in Queensland was no more than suspected. It had been tapped four years previously in New South Wales, but the boring appliances were so inadequate as to make the process tedious and of questionable practicability on an extensive scale. In Queensland some prospecting work had been done, and in some places fair supplies of water obtained by sinking ordinary wells.
But in the Far West there was little scope for enterprise in that direction. Hence some extensive dams were constructed across watercourses ordinarily dry, but without conspicuous success. For often the rush of flood waters either carried away the embankments, or the reservoirs they created quickly silted up, or the porousness of the subsoil could not be entirely combated by ”puddling.” Then streams at times complaisantly abandoned their old channels and formed new ones, leaving the intended reservoirs high and dry after the most deluging rains. After a time it was found that better sites than the beds of main watercourses could be found for dams, and that the construction of tanks would suffice in many places to provide sufficient water for a scattered population and the increasing numbers of live stock, although the expense of this mode of conservation was great for the limited supply obtained. Evidently, if the Far West was ever to be completely utilised, its almost illimitable areas of splendid pastures must be watered by some more effective means.
Attention was at this time attracted to the success of the few artesian bores in New South Wales, and to the vast scale on which water had been tapped by that means in the United States of America.
The chief obstacles, however, were the great depth at which artesian water might be expected to be found, and the utter inadequacy of the boring machinery then in use in Australia; moreover, the search was most needed in the areas practically inaccessible by reason of the absence of surface water. For a considerable time, as is disclosed in the digest of the Hydraulic Engineer's annual reports reproduced in Appendix H, little progress could be made.
It was not until October, 1884, in fact--just twenty-five years ago--that information was obtained of the striking of sub-artesian[b]
water by the Messrs. Bignell at Widgeegoara Station, close to the New South Wales border. The place was visited by Mr. Henderson, and by him reported upon encouragingly. In the same month the Treasurer received a letter from the late Hon. George King, of Gowrie Station, Darling Downs, directing attention to the ”Walking Beam Rig” machine, an American well-boring apparatus, by the use of which it had been ascertained that his firm might have saved 4,500 out of the 6,000 spent by it in well-sinking in the Warrego district. The letter being referred to the Hydraulic Engineer, that officer recommended the introduction of American bore-sinking machinery, and the engagement of American skilled drillers who would undertake to give instruction in the use of the machinery as well as engage in drilling work for the Government of Queensland. Delays occurred, however, apparently through the unwillingness of the Government to adopt the advice tendered. It was not until December, 1885, that Mr. Arnold, an American well-borer, was despatched to Blackall to sink a bore there. The first attempt failed, but afterwards water was struck in abundance, though not by him, or until after the first Queensland flowing well had been sunk by the Government at Barcaldine in December, 1887.
In April, 1887, the Hydraulic Engineer had visited Thurulgoona Station, and there found that Mr. Loughead, with the ”Canadian Pole Tool” boring apparatus, had obtained a supply of excellent fresh artesian water from a depth of 1,009 feet, the flow rising 20 inches above ground. From that date boring went on apace, and the exploratory success of the Government encouraged private persons to follow their lead. There were failures to strike artesian water, of course, both on the part of the Government and private persons, but on the whole the results have been such as to add to Queensland occupiable country equivalent to a great new province in the Far West.
[Ill.u.s.tration]
The map presented herewith shows the area of artesian water-bearing country in Australia as estimated by Dr. R. L. Jack, formerly Government Geologist. Since 1893 Queensland has been credited with the area of 376,832 square miles, this being equal to 56 per cent. of the estimated total. But that total has since been reduced to 569,000 square miles, and late information shows that the approximate area of the Queensland artesian basin, as ascertained by scaling off the most recent map issued by the Hydraulic Engineer, is 372,105 square miles--4,727 square miles less than the area given in his report for 1893. Yet the revised figures bring the Queensland artesian area up to 65 per cent. of the Australian total. The difference is accounted for by later information acquired in the field. Of the 372,105 square miles mentioned the area of 146,430 square miles has been tested and found to be less or more artesian or sub-artesian. Mr. Henderson says: ”The flows from many of the artesian bores which at one time or another yielded artesian water have failed, but owing to the suspension of the hydraulic survey the available data are quite insufficient to admit of a trustworthy estimate being made of the area so affected.”
[Ill.u.s.tration: FLOWING ARTESIAN WELLS, WESTERN QUEENSLAND]
The total supply of bore water has not been ascertained by actual measurement except from Government bores. But all possible reports of reputed flows have been obtained from the owners of private bores, and the figures cut down to 47 per cent. of the furnished estimates. This reduction is not an arbitrary one, however, but is the equivalent of the difference found to exist between the average estimate and the measured flow of such bores as the Hydraulic Department has been enabled to test.
Information from the Hydraulic Engineer's office shows that up to the end of May last there were 716 flowing bores in Queensland, pouring forth an enormous supply of sparkling water estimated at slightly over 479 million gallons a day, equal to a discharge of 175,000 million gallons per annum.[c] This flow, if conserved in tanks and pipes, would furnish a population of nearly 12 millions with 40 gallons of water per capita a day. It would irrigate 644,366 acres of cultivated land with 12 inches of water per annum.[d] An area so irrigated, utilised solely for wheat-growing, would produce, at 20 bushels per acre, nearly 13 million bushels of grain, which is equal to 2887 per cent. of the entire Commonwealth wheat crop for the year 1907-8.
The average Commonwealth yield for the last five years, however, was 61 million bushels. The average area under wheat for the same period was 5,864,114 acres, the average yield for the Commonwealth therefore being slightly over 10 bushels to the acre. As much wheat is cut for fodder, and as irrigated land should produce a largely increased crop, 20 bushels per acre for such land seems a moderate estimate. Moreover, in 1902-3, the Commonwealth crop was under 12 million bushels, or less than one-fifth of the mean average for the succeeding five years. At the same time the area of land under crop was in 1902-3 but little below the succeeding five-year average on an acre of land.[e]
The presumably perpetual daily flow of 479 million gallons of artesian water--the quant.i.ty named being equal to only 47 per cent. of the reputed flow in the case of unmeasured wells--has cost, so far as an estimate can be made, 1,873,515. This works out at the average of 2,616 per flowing bore, supplying 669,369 gallons a day. Calculating on the basis of 5 per cent., including interest and redemption payments, the annual charge for this money is equal to 131 per well, spread over a forty-one years' term, the average cost to each well-owner being thus 1 for 1,865,000 gallons of water a year. Thus, although much money has been lost in sinking unsuccessful bores, the investment has on the whole been amazingly profitable, even allowing that a further annual charge for maintenance must be added.