[Footnote a:] For fuller particulars see Hydraulic Engineer's Report for 1893, pages 5 and 6.
CONTROL OF FLOW NECESSARY.
The Hydraulic Engineer adds that while he cannot assert that the artesian flow is being exhausted, he yet holds that the flow ought to be controlled by legislative action.[a]
[Footnote a:] On this passage the Hydraulic Engineer notes that, in 1891, a bill was introduced into Parliament by Sir Thomas McIlwraith for controlling the artesian water supply, and passed through the Assembly, but was rejected by the Council. Since then no action in that direction has been taken.
IRRIGATION BY BORES.
The same report contains an interesting article on irrigation. It points out that at the beginning of 1892 there were only 200 irrigators among the land cultivators of the colony, and that the area irrigated was only 5,000 acres. It was believed that in the last year the amount of land so fertilised had largely increased. Many of the plants and distributing apparatus were of a most primitive kind. "Some are expensive, others badly erected, and not a few are of a type ill-adapted to the object in view."
The report goes on to discuss the probability or otherwise of water in sufficient quantities for irrigation being obtainable by conservation. In summarising his argument the Hydraulic Engineer says, "Looking at the question broadly, I am much disposed to regard the possibilities of a sufficiently abundant supply of water being obtained for irrigation, especially for land in small areas devoted to intense culture, as of considerable promise." He then urges the inadequacy of artesian wells for the irrigation of large areas, pointing out, among other things, that the entire discharge of the wells then flowing in Queensland would suffice to irrigate only 219 square miles to a depth of 1 ft. He thinks that in Queensland we shall have to depend upon "natural" water for irrigation purposes.
A VALUABLE MAP—376,832 SQUARE MILES IN ARTESIA.
A new feature in the 1893 report was the map giving information as to (1) artesian bores applied for, (2) under contract, (3) in progress, and (4) completed. It showed that out of a total of 668,497 square miles of the "Rolling Downs Formation" (Lower Cretaceous) no less than 376,832 square miles, chiefly in the arid west, was likely to be water-bearing. This estimate, it may be noted, has been very slightly reduced of late, but the scope for exploration in water-finding seems still great in Western Queensland. The report alludes to the success attained in the Queensland manufacture of well-boring machinery. All the plant used, the wire rope alone excepted, was manufactured in the colony, where improvements had been made in the originally imported article. Yet it is admitted that the apparatus used was "not a perfectly scientific one, because it does not produce a core by means of which the nature of the strata and the angle and direction of the dip can be fully ascertained." Queensland yellow-wood (Flindersia Oxleyana) had quite replaced American timber in the manufacture of drilling poles.
