The Hawea River has been temporarily reduced to well below its usual minimum permitted flow this week in preparation for the construction of a long-awaited whitewater kayak play park.
In a test run on Monday, Contact Energy's Hawea Dam operators, working in conjunction with Niwa, significantly reduced the volume of water flowing from the dam to reach the river level required for Fulton Hogan to build the park next to the Camp Hill Bridge at Hawea Flat.
Contact Energy environmental adviser Daniel Druce said the flow was dropped from about 13 cumecs to just over 4 cumecs over a period of about 10 hours, before being returned to its original state.
Normally, Otago Regional Council consents require the Hawea River flows to be between 10 and 200 cumecs.
"To support the construction of the kayak course at Camp Hill Bridge our consents allow us to work with the river as low as 3 cumecs," Mr Druce said.
"The purpose of Niwa was to deliver the flow accurately."
Today, the flow will be reduced again for Fulton Hogan to "better understand the river and to see what the construction site looks like at 3 cumecs".
During construction of the park, which was likely to begin in the next few weeks, the river flows could be reduced to as low as 3 cumecs for up to five consecutive days, Mr Druce said.
While river users should be aware of the fluctuating water levels, there were no real safety concerns as the change in river flow occurred "very slowly".
Central Otago Whitewater Club stalwarts Roy Bailey and Gordon Rayner pitched the idea for the kayak park about a decade ago. Since then, 14 separate consents from district and regional councils, the Department of Conservation and other organisations were gained, while consultation with the kayaking community and analysis of overseas whitewater play-park designs was undertaken.
The park has been designed by whitewater park designer Scott Shipley, of the United States, and will feature two large weir structures to restrict the flow of the river and create play waves for kayakers.
It will cost more than $500,000 to build and will be funded by Contact Energy as a mitigation measure agreed upon by Contact and the club as part of Contact's suite of resource consents for the Clutha catchment, applied for in 2001.
