Dannevirke Impounded Water Supply

Council passed resolutions that included funding of $3.2 million for raw water pre-treatment and $400,000 to purchase a raw water storage tank and a further $2.5 million for a 6 million litre treated water storage tank.
Council also decided to delay the delay the decision whether to repair the Impounded Supply. This was due to outstanding geotechnical investigations, supply challenges with sourcing a pre-treatment facility and issues relating to the impounded supply liner system.

The purpose of pre-treatment is so we can continue to treat water from the Tamaki River, even when the water becomes murky during heavy rain events. This should reduce the need to issue boil water notices. The extra water tanks will provide additional storage and resilience in periods of high water turbidity and low river flows.

This is because we are unable to deploy pre-treatment before May 2024, and we still need the stored water in the Impounded Supply until that time. In addition, we don’t have all the information yet to make an informed decision as to whether to repair or not.

A public water meeting was held on Tuesday 28th of November and a Facebook Live Q&A session will be held on Wednesday 29th of November. The focus on both of these meetings will be to answer questions from the community.
Due to the urgency of this issue, Council did not formally consult on installing the recommended pre-treatment and storage.
However, Council expects to consult with the community next year to make decisions on the future of the Dannevirke Impounded Supply.

Yes, the water continues to be safe to drink. Samples are taken every week from different locations across Dannevirke and tested. Installing raw water pre-treatment will provide greater resilience during extreme weather conditions

Yes, it is likely there will be water restrictions this summer because of dry weather conditions and low river flows. Our current resource consent requires Council to limit water extraction from the Tamaki River if it runs low. That means that Council cannot take enough water from the river to meet the town's water demands, which could result in water restrictions.

The likelihood of a long dry summer is one of the considerations leading to the recommendation not to dewater the Impounded Water Supply this November as was initially planned. This means that this summer, we can expect to have the stored water in the dam as a contingency backup. Work is also underway to investigate potential underground water sources. We will update the community in the near future about this .

The best way to prepare for an El Nino summer and any potential drought is to have a plan, harvest rainwater and think about water conservation in our daily lives. Council will also be providing regular updates and information on how to conserve water. Please remember to fill up swimming pools, and tackle those outdoor cleaning projects like water blasting now, while there is less/no pressure on our water supply.

After the temporary repairs in June this year, the impounded supply was stabilised, however, it has continued to present some deterioration and it is possible the volume of water held in the impounded supply will have to be reduced further. That is why
Council has decided to install raw water pre-treatment and additional treated storage capacity. Our teams are monitoring the impounded supply daily to watch out for any further deterioration. The impounded supply is physically inspected every day and electronic data is monitored daily.