The Hydraulic Engineer's report dated 11th September, 1890, supplies evidence of the importance of the discoveries made up to that date of artesian water in Queensland. The striking of a supply of 3,000,000 gallons a day of "water clear, colourless, soft, and potable" in the Charleville bore is noted with satisfaction. In the text of the report this was said to be, so far as the writer knew, the "best well in Australia," but a footnote added that soon afterwards a bore in the Cunnamulla district was reported to have been tapped with a daily supply of 3½ million gallons. The depth of the Charleville bore was only 1,370 ft., and its cost £2,389. The striking of a supply of 1,095,000,000 gallons per annum at so small a cost was naturally a subject for both official and general congratulation.
INFORMATION SOUGHT AS TO PRIVATE BORES.
In the same year is reported the striking of water in the Muckadilla bore, which yielded about 10,000 gallons a day from a depth of over 3,000 ft., and was then believed to be the deepest bore in Australia. The cost was £2,673. A somewhat better supply was afterwards struck at 3,262 ft. In this report the Hydraulic Engineer expresses regret that through the absence of barometrical measurements, owing to scarcity of money, the height above sea level of proposed sites for bores was not known, but sites were selected from surface indications and the results achieved by sinking in the neighbourhood. The wells sunk by the Government had been of much use in assisting private enterprise to select likely sites, but it would have been more satisfactory had better information been obtained by the use of the spirit level. Acknowledgments were made to those who had responded to the circular invitation sent out for information, and regret was expressed that in some cases there had been no response. The effort made, however, had enabled several new features to be embodied in the report, among which was a table containing a list of both public and private bores, and a large map locating, so far as possible, the position of each. Another map showed the rainfall in different parts of the colony, while a handsome diagram of the Brisbane rainfall was furnished for the first time. Both of these remained features of the Hydraulic Engineer's annual reports until 1901, when revenue considerations compelled their suspension.
HINDRANCES FROM FLOODS.
During 1890 excessive rains and bad roads hindered work in bore-sinking, instead of the dry periods which had been the cause of embarrassment for the preceding seven years. The only newly completed bore during this year was that at McKinlay, which at 1,002 ft. gave a supply of 224,000 gallons a day. Water was struck in two other bores, but of insufficient quantity, and work was still proceeding. The obstacles encountered in boring, often from the breaking of machinery, but more frequently from the want of thoroughly skilled drillers, must have been disheartening, especially in cases where the sinking was done without useful scientific information, and bores had to be abandoned after months—even years in cases—of labour and worry.
In his report of 20th January, 1893, the Hydraulic Engineer discusses at length the question of artesian water supply. The country is, he holds, now in a much improved position to encounter long droughts. Valuable information has been and is still being obtained by exploration as to the prospects of artesian water being found, and also as to the conservation of surface water by artificial means. He says that fifteen bores, averaging 1,571 ft. each, have been sunk by the department, and that although the work has been of a pioneering character only one sunk to the contract depth has proved a failure. He estimates that about 88,000 square miles in the western country have been proved to be water-bearing, and he urges that as large areas still remain to be explored the present is a favourable time for inviting tenders for the work.
STREAM-GAUGING RECOMMENDED.
In this report the Hydraulic Engineer directs attention to the necessity of acquiring information as to the extent of our surface-water resources. In three of the southern colonies, he mentions, a systematic practice of gauging streams has for some time been in force. The work will be useless unless it is carried on for a number of years. The essential thing to be ascertained is not the maximum flow of a stream, but the minimum; or rather, perhaps, the maximum that can be expected from a stream in a season of maximum aridity. "Without such data," he continues, "no fair distribution of water, no scheme of water supply, or irrigation, or drainage can be well considered; nor can storage and distribution or drainage works be economically designed, or their permanency and efficiency ensured." He therefore urges the matter of stream-gauging upon the favourable consideration of the Government, adding that the paramount necessity of active administration in respect of water conservation generally has been recognised by Parliament by legislation already placed upon the Statute-book.
WASTE OF ARTESIAN WATER.
Two official pages of the 1893 report are devoted to the "misuse of water," a member of Parliament having already objected to the application of the word "waste" to water allowed to flow unchecked from bores. The aggregate capacity of the ten Government bores then flowing was 5,000,000 gallons daily, all measured; while of the 137 private wells the flow was estimated at 100,000,000 gallons daily. This total of 105,000,000 gallons would be equivalent to a rainfall of 29 in. on 91 square miles of country. This was the rate of average rainfall on the assumed outcrop of water-bearing country that supplied the artesian area. And it had to be remembered that a part of this rainfall of 29 in. had to be carried off by streams as well as by evaporation, and therefore did not sink into the water-bearing strata of the arid west. As to the extent of the outcrop, it was estimated not to exceed one-eighth of a mile, with a total length of 1,600 miles, which meant a total supply of 200 square miles of water-bearing outcrop area.[a] Arguing on these and other grounds, the report contends that the falling off of the yield of many bores affords proof that, wherever the supply comes from, the outflow already exceeds the inflow. The Engineer can only regard as wasted two-thirds of the water that now flows from the artesian bores in Queensland; indeed, adopting the language of an American, "the waste is a crime against the well-owner and against the State."