Danny Walker, who has been involved in gold mining for 28 years, and has been managing a gold mine in Mongolia for the past 10 years, said if all the consents were granted he could start mining in winter next year.
‘‘There is gold there and I'm 90% sure this is going to be a viable concern,'' Mr Walker, of Golden Bay, said.
The project stacked up economically when gold was selling at $US500 (about $NZ630) an ounce, so it was looking even better, with gold peaking at more than $US1000 an ounce in the past few weeks, he said.
He needed to find about 3oz of gold a day for the project to be worthwhile.
Mr Walker told an Otago Regional Council resource consent hearing yesterday, that the building of the Roxburgh dam in the 1950s had helped clear the bed of the lower Clutha River of most of the light gravels brought down by dredging in the early 1900s.
In an earlier interview, Mr Walker said he wanted to be operating 24 hours a day for most of the year on the suction dredge, which he had not yet constructed.
He was granted a minerals permit in 2005 for about 60km of the river from Tuapeka Mouth to Roxburgh.
The dredge would have a 350mm-wide suction pump to scoop up bed material, which would go through various screening gates to find gold. The pump could scoop up about 20cu m of bed material an hour.
The dredge, about 6m wide, would be held in place by wire ropes, suspended above the river, and connected to the river bank.
The Clutha River was heavily dredged in the early 1900s, and most of the tailings from further up the river went downstream and covered the lower section of the riverbed, making it impossible to find gold.
Gold in the Clutha River is traditionally fine, and dredges 100 years ago lost about 50% of gold recovered, due to poor screening.
In the hearing, Mr Walker said, though he had done no exploration on his permitted river section, he had read all historical records, and talked to locals and believed there was gold in the area.
Dredge diving had been carried out but was difficult with changing river levels.
Advances in technology would make the dredge very quiet Dredging would be unlikely in spring, due to changing river levels.
Submitters Fish and Game Otago and the Department of Conservation had come to agreement with Mr Walker over conditions.
Council panel members Cr Stephen Woodhead and council chairman Stephen Cairns reserved their decision.
