Mayoral Column - Dannevirke Impounded Supply

26 June 2023

Firstly, a special thank you to all those involved in the massive week long operation at the Dannevirke Impounded Suppy. These teams worked seven days straight and well into the evenings to complete this work and including the weekend.
Through the exercise we now know more about the dam and the water flow diagram that has been printed prior proved to be correct.

We look forward to sharing more information with you at the public meeting on Tuesday and having our dam engineer from Tonkin and Taylor join us to help explain and answer any questions you have. We will also record the meeting and make this available on the council website and facebook.

The teams will now focus on planning for repair and meeting the new dam regulations that come into effect on May 1st, 2024. This repair will be planned for this summer and we will need to empty the dam and treat water directly from the Tamaki River. This will result in some restrictions and as we get further into the planning, we will share what this may look like so we can all make plans. We will set up regular communications so that everyone understands what is happening and how we are progressing.

There have been various lessons learnt and opportunities for improvement identified for the Dannevirke impounded supply. These include the inclusion of an additional protective layer between the liner and underlying material, further protection of the liner below the inlet structure, and improvements to how water is taken out of the impounded supply. These will be incorporated into the scope of the permanent repairs, to improve the future reliability and performance.

One common question is who is responsible and the answer is we are, as the dam was internally designed and met the regulations of the day. Our first priority is always to supply the town with water.

A NIWA scientist will join as part of the Mayors Recovery Taskforce for Cylone Gabrielle so we have the best information regarding the weather this summer.

Our aim is to keep you well informed.

Noho ora mai, All the best,
Tracey Collis - Mayor