About 15,000cu m of rock and gravel from the Victoria Flats landfill is being used to create the banks, at a cost of about $1.3 million.
The work, due for completion in September, is part of flood mitigation works, granted consent by the Environment Court in late January.
Horrell Contracting, of Queenstown, is carrying out the work.
Otago Regional Council environmental engineering and natural hazards director Dr Gavin Palmer said the "training line" extended out from the existing oxidation ponds at Frankton about 700m from the edge of the delta, where the Shotover meets the Kawarau River.
It was intended to prevent the Shotover River from entering the Kawarau River on the true right, or Queenstown side, of the delta.
The court had earlier granted consents for gravel extraction to achieve an ideal delta profile to reduce flooding in Queenstown.
Dr Palmer said the the gravel extraction would involve the removal of three main islands of built-up vegetation.
Studies showed the flood hazard for Lake Wakatipu was increased whenever the Shotover met the Kawarau at the western side of the delta.
However, Dr Palmer cautioned while the training line at the western side of the delta would prevent that happening, "it will not eliminate the flood risk for Wakatipu communities".
"It will stop the Shotover entering the Kawarau on the [Queenstown] airport side. Instead, it will end up on the other side of the delta. What we know from studies is the other side is better ... it will flood, but you could have worse scenarios, worse than 1999 [if the river is not trained].
The work would assist the passage of floodwaters at the junction of the two rivers and provide protection to the Queenstown Lakes District Council's proposed wastewater disposal field and also help direct the flow of the river and affect the deposition of gravel shifted by floodwater.
Council strategic project manager Martin O'Malley said the revetment line would reduce erosion and scouring on the river's western flank and was part of the $42 million Project Shotover.
Revetment lines are designed to prevent erosion of the land behind the line, and in this case, to minimise risk of pollution entering the Shotover and Kawarau Rivers during flooding.
"It is also a condition of the wastewater designation to prevent erosion of infrastructure put in place for treated wastewater disposal," Mr O'Malley said.
