Spinifex and Sand/Part VI/Chapter II
Part VI: The Journey Home
[edit]Chapter II: Sturt Creek and "Gregory's Salt See"
[edit]The Sturt Creek presents many points of interest. It rises in the Northern Territory, runs for nearly three hundred miles in a South-Westerly direction, and comes to an end in a large salt-lake, across the border, in the desert. It runs throughout its entire length once in every three or four years, though each yearly rainy season floods it in certain parts. In the dry season one might in many places ride right across its course without being aware of it. In the wet season such parts of it are swamps and marshes, over which its waters spread to a width of five and six miles. Permanent pools are numerous, and occur wherever a ridge of sandstone rock runs across the course of the creek. On either side of the creek fine grass-plains spread East and West. The further South the creek goes, the less good is the country on the East side; presently there is no grass country except on the West side. Not far below the station the creek is joined by the Wolf, which, like all Kimberley creeks, is fringed with gums, Bauhinia, and Leichardt-trees. From the confluence downwards a war between the grass-lands and the desert is waged for the supremacy of the river-banks. For miles the sandy channel, cut out like a large drain through the country, less than one chain wide in places, is hemmed in on either side by desert gums and spinifex, and once out of sight of the creek the surrounding land receives no benefit from the water.
But lower down again, about the latitude of Mount Mueller, the grass plains gain the day; and a very pretty bit of country they form too, especially when the creek is running, as it was when we were there. In many places its waters had overflowed the banks, expanding into clay-pans and lagoons of beautiful clear water where teal and whistling duck disported themselves.
The Wolf rises on the opposite slope of the watershed to Christmas Creek and the Mary River, and floods twice or thrice a year. Below its junction with the Sturt the combined creek takes on itself the character of the Wolf, and at the point of confluence the Sturt may be said to end. Seeing how seldom the Sturt runs its entire length and how small its channel is at this point, smaller than that of the Wolf, I think that it is to the latter that the lakes (Gregory's "Salt Sea") chiefly owe their existence. However that may be, the combined waters fill but an insignificant channel and one can hardly credit that this creek has a length of nearly three hundred miles.
On nearing the lakes the creek assumes so dismal an appearance, and so funereal is the aspect of the dead scrub and dark tops of the "boree" (a kind of mulga), that one wonders that Gregory did not choose the name of "Dead" instead of merely "Salt Sea." A curious point about this lower part of the creek is, that stretches of fresh and salt water alternate. The stream, as we saw it, was only just running in the lower reaches; in places it ran under the sandy bed, and in this part the salt pools occurred. First we passed a stretch of clear, brackish water, then a nearly dry reach of sand, then a trickle of fresh water lasting for a hundred yards or so; this would again disappear, and be seen lower down as another salt pool.
The creek enters the first lake in a broad estuary; this lake is some four miles long by two miles wide, lying North and South. At the southern end a narrow channel, 150 yards wide, winds its way into the large lake beyond, a fine sheet of water, eight miles in diameter. A narrow belt of open country, overgrown with succulent herbage, fringes the margin of the lake; beyond it is dense scrub, with occasional patches of grass; beyond that, sand, sandhills, and spinifex. In the distance can be seen flat-topped hills and bluffs, and rising ground which encloses the hollow of the lake. The lake has no outlet; of this Gregory satisfied himself by making a complete circuit of it. At the time of his discovery the lakes were dry, or nearly so, and doubtless had the appearance of being shallow depressions, such as the salt lakes in the southern part of the Colony; so that having followed the Sturt for so many miles — a creek which showed every appearance of occasionally flooding to a width of five or six miles — he must have been somewhat uncertain as to what happened to so great a volume of water. However, the lake is nearly thirty feet deep in the middle, and, from its area, is capable of holding a vast amount of water. The creek, below its confluence with the Wolf, is continually losing its waters, throwing off arms and billabongs, especially to the west, which form swamps, clay-pans, and lagoons. So much water is wasted in this manner that near the entrance into the lake the creek is of a most insignificant size. The fall, too, is so gradual that the water runs sluggishly and has time to soak away into the enclosing sand.
Mr. Stretch tells me that it takes eight days for the water from rain falling at the head of the Sturt to pass his homestead, which gives it a rate of one mile per hour. Heavy rains had fallen at its source about a month before our arrival, and the water was still flowing. We therefore saw the lakes as full as they are ever likely to be, except in abnormal seasons. North of the lake are numerous large clay-pans which had not been flooded, and the lakes could evidently hold more water, and had done so in time past, so that it is pretty clear that the lakes are large enough for ordinary flood waters, and, with the outlying clay-pans, can accommodate the waters of an extraordinary flood.
I feel confident, therefore, that no outlet exists, and that beyond doubt the Sturt ends at the Salt Sea, and does not "make" again further South, as some have suggested. Standing on any of the hills which surround the lake, some distance (ten miles or so) from it, one can look down upon the water, certainly five hundred feet below the level of the hills, which rise no more than eighty feet above the surrounding plain. It seems most improbable, therefore, that a creek should break its way through country of so much greater altitude without being seen by Colonel Warburton or myself, or that any connection should exist between the Salt Sea and Warburton's Salt Lakes to the South-East.
Had, however, the intervening country been of the same level as the lake, and flat instead of formed into high sand ridges and hills, there might have been a possibility of crossing a connecting creek of the same character as the Sturt without noticing it. This question has been much discussed by gentlemen interested in the geography of interior Australia, and therefore I have dealt with it at some length.