The History of Australian Exploration from 1788 to 1888

by Ernest Favenc

In approaching the subject of our subterranean water supply, the peculiar physical formation of Australia must be borne in mind. The great flat tableland that stretches in almost unvarying monotony from shore to shore, fringed round with its strip of coastal land, resembles—to use a homely simile—nothing so much as a narrow brimmed, flat crowned hat. The moisture-laden clouds that visit us, break on the sides of this hat, giving the brim, or coast, the full benefit of their precipitation; drifting over the plateau, or crown, with rapidly decreasing bulk. Thus, the great plain, in size the greatest, and in soil the richest part of us, is always labouring under the curse of irregular and inefficient rainfall; and whatever good we may do in the way of water storage and we may do so much-we have always the threat of many years of drought hanging over, during which our treasury of water will be drained, and not replenished.

Welling from the sides of the tableland we find large permanent springs, in many cases the sources of fine strong-flowing rivers, the component parts of whose waters now first see the light again after countless ages. Storms and floods may come and go unheeded, their steady flow is-maintained unchecked by summer or winter weather; for their birth is deep down in the earth, where meteorological disturbances are unknown. Like an old and battered tank, through whose cracked and leaky sides the water it contains is escaping, so these springs find vent through fissures in the mighty tableland, to flow down to the sea.

Up in the northern provinces where, perhaps, if anything, the contrast of these flowing streams beneath the parched surroundings is more striking than in the more temperate southern clime, there are some mighty leaks in the sides of the tableland. The Gregory River, in the Burke district of Queensland has one unvarying flow; a strong running stream, never lessened by the longest drought, but gliding beneath cool masses of tropical foliage and gurgling over rocky bars when all around is dry. What a great heritage here runs to waste unheeded.

In the northern territory, from out another vent, springs the Flora River, whose waters ripple over limestone bars in miniature cascades, from pool to pool, like pigmy reproductions of the lost terraces of New Zealand. Follow the edge of the great tableland around, and amongst the deep seams and fissures of its abrupt descent coastward, we suddenly come, midst rugged barreness and gloomy grandeur, upon these messengers from the inner earth. Some enjoying the sunlight, but for a brief span, disappearing again for ever as, suddenly as they were up-borne; others finding their way down to the habitable lowlands and to the sea. But, unfortunately, all these springs, some of great volume, find issue on the outer edge of the range; the gradual descent that marks the inner slope is not the scene of these outbursts. Here, and throughout the interior, the waters from below rise in a way that seems to best befit the weird solitude of the great plain.

At times, on a bare, baked mound elevated above the surface, there is a dwarf crater filled with water that never overflows, and when tapped and exhausted, rises once more to its former level. Again, canopied by giant ti-trees amid the shrill shrieking of thousands of noisy parrots, the traveller can pick his way along the treacherous paths that wind amongst the hot springs. Or at the foot of a low range a scanty trickle fills a rocky pool, and thence is lost.

In the bed of some far inland creek, the water rises in the sand in shallow pools, during the dark hours of night, to vanish once more beneath the sun. And in low caverns in the limestone hills, down some deep fissure, can be seen the waters of a stream, whose rise and course no man has ever traced. Again a solitary lagoon is found whereon no lily grows, and wherein no fish swims. Where the belated bushman camping for the night, finds the next morning that the water has sunk many feet, or perhaps has risen, when no rain has fallen far or near for months. All these signs and tokens from the great sea beneath us may serve as guides to the end.

When one comes to know the real value of water in a thirsty land, it almost seems like a crime on the part of Nature, that a spring should rise and flow for a comparatively short distance, to be lost in the sea. When by placing the source some fifteen or twenty miles away the course would run for hundreds of miles through a dry country. Can human ingenuity improve on nature?

In this case nature seems to have laid the ground work of a great comprehensive continental plain; to have put the lever ready for man to start it, and though the scheme is one of such magnitude that it may at first glance seem widely impossible, there is no reason, backed as it would be by natural forces, that it may not be an accomplishment of the future.

To fully understand the great problem of the water supply of Australia, it is necessary to comprehend and carry in mind the wonderfully unique river system of the continent. In an average area of 1,800 miles east and west, by 900 miles north and south, the whole drainage runs from north to south; that is to say, all that finds vent in the ocean. This, of course, is the surface formation carrying off the rainfall, and has no bearing on the outbreak of subterranean springs. But, as showing the upheaval of the land to the northward, it points out that naturally the flow of irrigation on a large scale will be from north to south.

It may be said that from the 18th parallel there is a steady slope southward, broken only by the subordinate natural features of the country, which necessarily form the irregularities of the smaller tributaries. In this great block of more than a million and a quarter of square miles there are then all the defined channels requisite for the carriage of water throughout the heart of the continent, but with the important fact wanting that they are destitute of a constant and steady supply from the doubtful rainfall. The tilt of the northern edge of the plateau puts their sources above the level of the great springs, and causes them to be dependent on these intermittent and often scanty rains. And we know that these rains have failed in producing any comprehendable system of drainage over one third of our continent, at, least, at present with our limited knowledge, the water system appears wasteful and purposeless throughout that region.