by John Douglas
The majority of Otago's gold was found in the rivers and the river terraces - in particular that of the Shotover, Kawarau and the Clutha rivers. Fortunes were made and lost in these rivers in the first big gold rush period 1862 -1864. Once the easy alluvial river shallows and sand bars had been worked, small groups of miners got together, constructed races to carry water to these gravel terraces along side the rivers and then with powerful water monitors, sluiced away the terraces to enable more gold to be won.
While most were working the terraces, others were eyeing the deeper riverbeds trying out various methods to recover the course and fine gold drifts deposited long ago, along the bottom of the rivers. They first used the spoon dredge, followed by the current wheeler. Not till the 1880's, that they finally found a method to be successful - the " McQueen's" steam powered bucket-and-ladder dredge. Initially these early dredges could only work the river shallows, low beaches and the river in winter when at its lowest. Twenty years of improvement soon had dredges with bigger bucket ladders to work the rivers beds of 12 metres as well as to make it possible to break through the younger riverbeds down to the older riverbeds. Then in 1894 see the development of the "tailings elevating", allowing the dredge to move into the higher beaches and paddocks away from the river, working in their own pond, stacking the discarded gravel as tailings well away from the dredge.
The main dredging period was from the early 1890's to 1905 with some 100 dredges working the Otago Rivers. Where there was local coal available eg, Cromwell, Alexandra, Roxburgh, Nevis Valley, it made dredging more variable as it reduced considerably cartage costs. Alexandra became the centre of the dredging boom. In its heyday, as many as 30 dredges could be counted from the trig above Alexandra though many were not successful. Alexandra had its own coalmines right alongside the Clutha and the Manuherikia rivers. The stretch of the Clutha below the Cromwell Gorge to the top of the Roxburgh (Molyneux) Gorge was considered to have the richest concentration of gold from current bedding ever known in the world. Another rich stretch was that at the Kawarau Junction.
Then came a period of little or no dredging. Coal was coming too expensive as well as becoming too dangerous to mine, though a few dredges were now being powered by electricity. Also most of these dredges of the early 1900's were incapable of going deeper than 15 metres - often the richest gravel layer was at 20 - 25 metres.
The redevelopment of the electric power dredge in the late 1930's again saw on the Clutha River, three big and powerful dredges working on or beside the river. The Molyneux worked from Clyde to the lower Kawarau River for very poor returns and ceased in 1942. The Alexandra (Clutha River Gold Dredge Co.) worked down the Roxburgh Gorge, later onto the Alexandra Flats and then over onto the Earnscleugh Plains. The last, the Austral-N.Z. (Austral Malay Tin Ltd's dredge) worked the Lowburn area, Upper Clutha basin. These last two dredges made steady returns and both eventually had too cease due mainly to lack of or access to available workings. The Austral-N.Z. in January 1952, with the Alexandra following 11 years later, March 1963.
A more recent dredging assault was that on the Shotover River in the late 1980's/early 1990's. Though we have now properly seen the last of the big dredges, there is still large-scale gold mining extraction going on at Macraes Flat and L&M now working the Earnscleugh Plains using a recovery plant - a large look alike dredge with front end loaders replacing the bucket chain.
The best evidence of the dredging era can be seen at the massive Earnscleugh Tailings alongside the Clutha River. Access to this Goldfields Historical Reserve (1989) is made from the Fraser River, bottom of Marshall Road down Fraser River RHS track to Clutha River, across the bridge and back up Fraser River LHS track. The smaller tailings closest to the river cover the period from the late 1890's to the mid 1920's while the bigger tailings are more recent, from the 1950/60 period. Walking through the tailings you will discover old hidden dredging ponds, the occasional bucket and as well it also makes for an interesting nature walk. Opposite at the Muttontown Tailings between the Clutha River and SH 8 in a pond, lies the remains of the hulk believed to be the Dunstan Lead, (renamed the Earnscleugh No 5), abandoned back in 1924.
Dredging in the Nevis Valley took place in the late 1890's right through to the late 1930's. Traveling along the Nevis Road through both the Lower and Upper Nevis Valley there is still a landscape of largely untouched tailings, some small dredging ponds and as well, old water races, sluicing scars and of old home remains.
Tours to old tailing sites, other Historical Goldfields of Central Otago, wild flower walks and general tours can be arranged with John Douglas of Safari Excursions Tours.
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