Additional Treated Water Reservoir
Planning is underway for an additional treated water reservoir in Dannevirke, which will strengthen the resilience and reliability of the town’s drinking water supply.
The new reservoir is planned to be located next to the existing treated water reservoir and will provide additional treated water storage for the community.
Why is a new reservoir needed?
The existing treated water reservoir was built in 1969 and a recent seismic assessment identified that it is vulnerable to significant damage in the event of an earthquake. As the structure continues to age, this risk is expected to increase.
The new reservoir will provide additional storage and allow the existing reservoir to be temporarily taken out of service for strengthening and maintenance, without disrupting the town’s drinking water supply.
Additional storage will also help meet Dannevirke’s future water needs.
How much water will the new reservoir hold?
The existing treated water reservoir has a storage capacity of 4,550 cubic metres, which provides approximately 18–22 hours of water supply if the town were relying solely on this reservoir.
The new reservoir is planned to have the same capacity.
With both treated water reservoirs available, Dannevirke would have approximately 36–44 hours of treated water storage if relying solely on the two reservoirs.
This additional storage will provide greater flexibility and resilience for the town’s drinking water supply.
What has been done so far?
Planning and design investigations have been undertaken to:
- Identify the preferred location for the new reservoir.
- Determine the required capacity.
- Define the performance requirements for the reservoir and supporting infrastructure.
- Complete initial geotechnical investigations and technical assessments.
What happens next?
Planning for the additional reservoir is continuing, with the project expected to progress in the 2027/2028 financial year.
As part of the transition to the new water services delivery model, the project will transfer over to Waitī Waters to progress through its next stages.
Further work will include confirming technical requirements, progressing detailed planning and design, and preparing for the construction phase.
The timing of future works will be confirmed as planning progresses.
How does this relate to the impounded water supply?
The additional treated water reservoir is separate from the Dannevirke impounded water supply.
The impounded supply stores raw water before it is treated at the water treatment plant. The treated water reservoir stores water after it has been treated, ready to be distributed to the community.
Both are important parts of Dannevirke’s water supply system, but they serve different purposes.
The additional treated water reservoir is intended to increase treated water storage and resilience, while also allowing the existing treated water reservoir to be strengthened in the future.