Aratiatia rapids.

A little further downstream is the Aratiatia dam which is used for hydro electricity generation.

A few times each day, spill gates from the dam are opened at the top of the Aratiatia rapids and the narrow gorge fills with turbulent water surging past at up to 90,000 litres per second. Then, as the gates are closed about thirty minutes later, the turbulence recedes to a placid stream. By seeing the transition to full-flow and back again, visitors can fully appreciate the power of nature.

At Aratiatia the Waikato River falls naturally through 28 metres in the space of one kilometre. This natural drop has been harnessed for environmentally-sustainable hydroelectric power - headwaters are diverted through a tunnel to the power station. Each day at 10am, 12 noon and 2pm - and also at 4pm in summer - the flow through the Aratiatia rapids is allowed to resume its natural rate. There are several excellent vantage points on the high rock bluffs that dominate this turbulent stretch of the river.Read more