Tēnā koutou katoa Greetings to you all
The wonderful rain over the last weekend gave our gardens a good soak, filled rural water tanks and increased the flow in our rivers. While the this will help our water supplies, the rainfall we experienced increases the turbidity of our river sources meaning we cannot immediately increase our water take. Many of our water treatment plants can manage turbidity, but Eketāhuna is the main exception where precautionary boil water notices are required on a regular basis after heavy rainfall. This water treatment plant is currently being upgraded, including increased storage and filtration, which will reduce (but not eliminate) the risk of boil water notices in the future. We thank residents for their patience with the precautionary boiled water notices we are required to issue when any risk is present. The water is tested and must be clear for three days before the notice can be lifted.
Our river turbidity levels reduced and the Tamaki River level rose enough to allow us to start filling the impounded supply on Thursday. Current water restrictions will remain in place, enabling water to continue to be added to the impounded supplies in both Dannevirke and Woodville.
There is much discussion around the infrastructure failure at the Dannevirke impounded supply, including some misinformation. A compacted clay layer was placed between the liner and underlying material to protect it from stone damage – as was the general standard at the time. It met all the requirements with appropriate sign offs. The guarantee for the liner was five years and the expected lifetime of the liner was about 25 years as it is a very durable plastic.
Further investigations into the possible remaining leak will continue after summer, as well as an assessment of other risks and opportunities associated with the impounded supply.
We plan to be harvesting the discharge water by the end of next week. Most of the infrastructure is now installed and testing of the new pump is hoped to be carried out Friday or Saturday, weather dependant.
Horizons reported that Autumn 2021 was the driest in 112 years. Our seasons are changing and it was hopeful, or we were wrong, to imply that our impounded supplies would prevent water restrictions ever in our changing climate.
We will continue to work on all aspects of water and the team continue to focus on getting us through.
Noho ora mai. Tracey Collis | Mayor