Whangamatā Stormwater Project

• Project typeStormwater infrastructure
• Project value$9.2 million
• Completion Date30 June 2030

Whangamatā Stormwater

The township of Whangamatā has been facing stormwater issues for some time. To ensure a coordinated approach to remedial work, our Council is undertaking a stormwater modelling exercise to understand the issues and where work needs to be carried out. The outcome of this study will be available for public view on our website later this year.

$9.2M of capital funding has been sought through the 2024-34 Long Term Plan to address stormwater issues in Whangamatā. If funding is approved by our Council, then it is proposed to commence the work programme in July 2024. Details of the above funding request can be found on Page 5 of the capital expenditure project lists document on our Council website.

Our Council has already been working with a group of Whangamatā community representatives, the Community Board and Council members regarding these stormwater issues. Council has also met with local iwi. Everyone’s input to date is sincerely appreciated and these working arrangements will continue.

As part of addressing the stormwater issues in Whangamatā, our Council has commenced site works at the Williamson Park Pond. The purpose of this project is to drain stormwater out to sea quickly and without excessive ponding at this location.

Following community feedback, the project will be carried out in three stages as described below. Stages 1, 2 and 3a will be completed by early July. The performance of these new works during a major storm event and discharge water quality will be monitored. Should testing show that the discharge water quality is of an unacceptable standard, then Stage 3b will be implemented to improve this water quality before discharging into the sea. We will keep the community informed if Stage 3b needs to be implemented.

During the implementation of the above works, some of the trees adjacent to the pond will be removed.

Stage 1: Upgrade works at the outlet weir.

Stage 2: Construction of new manholes with a sediment capture system at the inlet.

Stage 3: Pond Area – area stays the same as current pond for both 3a and 3b stages.

• Stage 3a: Construction of a Dry Pond. This work involves filling in of the existing pond with soil to elevate the existing pond floor to the same level as that of the existing inlet pipes inverts. This will allow water to flow directly from the inlet pipes down to the weir and out to sea.
• Stage 3b: Wetland works - If the water quality analysis shows that we need to improve the quality prior to discharging into the sea, then the dry pond will be converted into a wetland. The water will then flow from the inlet pipes and over a wetland to the weir before heading out to sea. The plants in the wetland will provide natural cleaning of the water.

Our Council wishes to thank everyone who attended the public meeting at Williamson Park Pond Whangamatā on Friday 31 May and looks forward to continued community engagement as we work to address these stormwater issues in the township.