The information that little more than one-half the area of the artesian basin in Queensland has yet been explored is in some respects disappointing, but it is reassuring in others. For if the unexplored country yields as much water per square mile of surface as is now pouring forth from the wells on the tested area—which is not yet fully developed—the total daily yield will ultimately approach 1,000 millions of gallons. Never, according to official information, was bore-sinking more active than it is during the current year, and the thoughtful reader will sympathise with Mr. Henderson's repeated expression of regret that want of money some years ago compelled the department to discontinue both exploration on scientific lines and the periodical measurement of all artesian flows. For with careful surveys of the entire water-bearing area much capital might be saved by teaching where copious springs might or might not be expected to be met with; while with measurement and registration of all flows the question as to the perpetuity or the contrary of the supply would be placed beyond controversy. In that case legislation could be initiated with confidence, and the public interest safeguarded with the least possible disturbance of private interests.
An important consideration in connection with the artesian area is that the land watered by bores is as a rule more than commonly fertile. Its pastures produce some of the most nutritious natural grasses and herbage found on the face of the earth; and, what is of immense significance, they are grasses and herbage that either would not live or would deteriorate under a tropical sun, with a rainfall equal to the coastal average. Thus it may be argued that artesian bore water—at any rate, when so free from mineral impregnation as to be unquestionably potable—is more valuable, gallon for gallon, than the supply direct from the clouds.
In several of his numerous reports the Hydraulic Engineer makes reference to the subject of irrigation by means of artesian water. It is certain that the water from some bores, while useful for live stock, is not fit for either domestic use or for irrigation. The Hydraulic Department many years ago began what was intended to be a systematic analysis of bore water with the view to providing an official record that would be highly useful for public purposes. But in one case at least water pronounced by the Government Analyst as useless even for stock was highly esteemed on the run whence it was obtained; and evidently much has yet to be learned as to the value of subterranean waters not regarded as potable by scientific standards.
Some of the most copiously flowing bores, however, discharge water of unexceptional quality, whether for domestic use, manufacturing purposes, or irrigation. The Hydraulic Engineer doubts, having regard to the immense quantity of water required for irrigation, whether it will ever be found useful for that purpose in so far as the greater agricultural industries are concerned; but for intense cultivation around the homestead he thinks bore water might well be utilised. In some cases it would be in sufficiently large supply for the raising of green fodder for stud stock—perhaps even for protection against minor local droughts. An irrigated crop needs three or four waterings of 3 inches each, and as each inch means 22,614 gallons, the quantity required for a crop, with four waterings, would be 271,368 gallons per acre; so that a cultivation plot of 20 or 30 acres would absorb from 5 to 8 million gallons a year, according to the seasons, the nature of the soil, or the soakage.
While doubtful as to the suitability of bore water for irrigation on a large scale, Mr. Henderson strongly advocates its being applied to machinery of small power. Many years ago he directed attention in one of his annual reports to the extensive use of water power in competition with steam in certain parts of America; and it is satisfactory to note that in some inland towns of Queensland the American example has been followed. In quite a number of towns the public water service is artesian, and in a few it is the motive power of electric lighting systems. The information that the flowing wells of Queensland are discharging daily 320 million gallons of water "to waste" indicates that when population in the artesian area becomes more dense bore power will become an invaluable aid in economic manufacture. The water so harnessed would not be wasted, as every gallon would still be available for human or animal consumption.
ABERDARE COLLIERY, IPSWICH DISTRICT
The money value of the water annually discharged from the flowing bores of Queensland runs into stupendous figures, even at the rate of 6d. per 1,000 gallons. At that rate its annual value would exceed 4¼ millions sterling. Capitalise this sum at 4 per cent., and the artesian water flow of Queensland becomes worth upwards of 109¼ millions sterling, less, of course, the cost of maintenance and supervision similarly capitalised. And this colossal endowment is the result during the last quarter of a century of a total expenditure of less than 2 millions sterling. Granting that to utilise all this water already under pressure would mean a very large additional expenditure in tanks, aqueducts, and pipes, that expenditure may be calculated in advance to a minute fraction in every case, and it would of course be disbursed gradually as the demand for the delivery of water under pressure developed with the increase of population and the multiplication of industries. It must be apparent, therefore, that any needful public expenditure to ascertain whether the flow diminishes or increases as the years go on, and to prevent waste if waste there be, is more than justified. Indeed, should any great public loss be suffered for want of State control of this life-giving national asset, it might be difficult for Parliament entirely to clear itself from blame if charged with neglecting the reiterated advice of its own responsible officer in this respect.
[Footnote a:] For digest of Hydraulic Engineer's reports, 1883 to 1908 inclusive, see Appendix H, post.