Of Drought and Flooding Rain EarthCache
Of Drought and Flooding Rain
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According to Dorothea Mackellar, Australia is a land of drought and flooding rain. If you wait long enough at this location, you will see both.
The majority of the River Torrens’ water comes from the Mount Lofty Ranges, with the lower catchment area containing the headwaters of the First to Fifth Creeks, which are featured in Freddo’s Up the Creek series of caches. (Sixth Creek being in the upper catchment area.) It was the major source of water for the settlement of Adelaide, although the subject of scathing comments about its quality. The editor of the SA Gazette & Colonial Register wrote in 1838:
What the River Torrens may be capable of performing for a week or two of the rainy season beyond sweeping down to the swamp the summer filth of Adelaide we cannot guess; but the Torrens at other times is not a river at all, but merely a chain of ponds. At the present moment, its running water may be spanned with the hand and sounded with the forefinger. It has ceased to flow immediately below the town, and is from thence downwards a very formidable dry ditch.
However, the river is capable of becoming a raging torrent. The largest recorded flood since White settlement was on 22 September 1844. Geoffrey H Manning wrote in A Colonial Experience:
In September 1844 for more than two hours excited colonists watched the swollen and angry river at work. In apparent safety we saw the river eating away at the foundations of Shand's brewery situated to the east of Adelaide. That the building was doomed was evident. The unfortunate owner and willing helpers carried many of the casks and other utensils of the brewery to safety.
By four o'clock the building was undermined and down it came with a tremendous crash. Amid falling debris, and with the water swirling close to them, the onlookers ran for their lives. As it was, many of them had narrow escapes from death by injury or drowning for, to add to the confusion, a large portion of the bank fell in with a great rumble, and showered the bottles, casks and brewing utensils floating in the river with clods of earth. The despised Torrens was in flood and having its revenge for the contemptuous remarks that had been hurled at it.
The first dam built on the Torrens was washed away in 1867 and replaced with a still-existing weir in 1881. Probably the most damage was caused in the 1899 flood after a yearly rainfall of 785.6 millimetres of rain compared to the Adelaide average of 530 millimetres. The river flooded market gardens and farms throughout its course, causing extensive damage. Norwood was inundated to The Parade, Adelaide to Pirie and Rundle Streets, and many areas west of the city were left in a shallow lake. The river ran 9 feet (2.7 m) deep over the weir near Thorndon Park Reservoir, 3 feet (0.91 m) over the Torrens Lake Weir and 1-foot (0.30 m) over the Morphett Street Bridge. The Underdale (or Holbrooks) Bridge was destroyed, the Torrens Lake weir's bridge damaged, and the Felixstow Bridge over the Fourth Creek washed away.
In the 1980s the area along what is now the River Torrens Linear Park was cleared of exotic vegetation and landscaped for flood mitigation. Although parts of Campbelltown and Paradise are still flooded from time to time, the damage is not nearly as severe as in previous years. Owl and Raven are fortunate to live well above the highest flood levels, but are in a position to watch the ebb and flow of nature.
November 2005
November 2005
November 2006
November 2006
In order to claim this Earthcache you must email the following details to Owl:
- From this location you can see the River Torrens and another watery feature (which may or may not actually have water in it).
Describe the current water levels of each feature. Use the supplied pictures as a comparison between past and present levels.
- Try to imagine what the river and its surrounds looked like originally. What changes to the landscape would have helped with flood mitigation? Remember to include the purpose of the pond. (If stuck, googling 'river torrens flood mitigation' will get you a number of government sites which can provide further information.)
- Can you still see evidence of past floods in the area? (This may include your observations of the geological features on the opposite side of the river.)
Optional: Take a photograph of the site as it is today.
Optional: Briefly tell a story from your experience with the Torrens River. Have you seen it in flood or did you play near it as a child?
Note: Owl is a historian, not a geologist, so there is no need to use technical language in your descriptions.
Important: If the location is underwater, make your observations from the nearest suitable location. Never enter flood waters.
Additional Hints
(Decrypt)
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