Built in late 2012 and located on the Hawea River at Camphill Bridge, the Hawea Whitewater Park (or Hawea Wave as it’s called by most) is a man-made structure within the Hawea River itself.
The park has two river waves for kayakers and rafters, bodyboarders and surfers, to play and train on. When the Hawea Dam is released, the correct water flow provides the perfect standing wave (i.e. the wave stays in the same place).
The Hawea River flow is managed by Contact Energy, specifically for electricity generation. Releases are made based on power requirements. From the 1st of September to 31st of January Contact Energy are required to ensure that the flow is kept between 10 to 60 cumecs. Outside of this time, month releases are usually performed from 8am to 8pm on the first Saturday and Sunday of November, December, January and February.
Note the it usually takes an hour or two for the increased water flow to properly affect the wave itself. See this website for current water flow.