The narrow gorge links the headwaters of the Rangitata River with the fertile Canterbury Plains.
It is also a popular river for visiting kayakers, fishermen and adventurist locals in jet boats.
The gorge is a class IV to V+ depending on the flow of the river and home to the notable rapids including Rooster's Tail, Pencil Sharpener, The Pinch, Pigs Trough and Hells Gate.
[2] Today the race is 67 kilometers long and carries a maximum of 30 cubic metres of water per second.
After supplying irrigation demand, the canal discharges the remaining water via Highbank Power Station into the Rakaia River.