For the past 12 months, the Wanaka Marina management team has been working with ORC, QLDC, and other parties to determine the cause of the delta build-up on the inside of the Marina, adjacent to the Marina Terrace development site outflow. Every effort was made to have this work completed prior to the completion of the recently opened boardwalk.
QLDC has conducted their own research and has offered the following solution…
“Sorry that this has been so drawn out but it has been a challenge to determine the source of the sediment, nevertheless from the images you have provided the problems are at the end of the pipe, so this is where we are proposing a solution.
The image below is a concept of the solution, a relatively simple solution of placing rock structures (detailed design being done) around the outlet, this will provide two positive effects.
1. It will reduce the flow velocities from the pipe which will allow the sediment to settle more before leaving the network but more importantly it won’t have the energy to push the sediment out into the marina.
2. The structure will create a catch basin that sediment can easily and periodically be removed from.”
No timeline for the above has been given.
An independent consultant engaged by Wanaka Marina Ltd has done his own testing and measurement and is of the professional opinion that the proposed QLDC measure will not be effective.
Work continues toward pushing for an effective solution at removing the delta build-up and mitigating future sediment build-up inside the marina.