Papawai Stream Erosion Mitigation

Following on from phase 1 works completed in June 2025 to provide protection to the eroding streambanks prior to the network intake, we are undertaking further erosion mitigation works to increase channel capacity and improve flood resilience at Papawai Stream, Mount Cook.

Phase 2 works include construction of an in stream gravel trap to manage sediments from the upper catchment and realignment of a section of the existing bund to improve flood conveyance and restore its intended flood mitigation function.

Crews from Mills Albert, who are completing this work on the ground, have started setting up onsite. Further site setup will be underway this week, with some noise expected as part of the rock delivery at the end of the week. Physical works are expected to start from next week Monday 8 June.

Figure 1. Project sitemap outlining vehicles movements and parking that may be impacted.

Below are key things to note about the impacts during these works: 

•    Construction is expected to take place between June and August 2026.
•    Hours of work will be between 7.30 am and 5.30 pm from Monday to Friday. We’ll notify you if any Saturday work is required in the next few months.
•    There will be an increase in work vehicles in your neighbourhood, specifically if you’re along Salisbury Terrace and Wright Street.
•    There will be noise and some vibration during the works from machinery and rock movement which crews will keep to a minimum.

Once the rock delivery is completed this week, crews will focus on constructing two gravel traps along the stream bed. This will include bulk excavation, bund formation, subgrade preparation, timber pole base lining, and rock placement works.   

Key contacts 

If you have any concerns or questions while the investigations are being done, please contact Paul Ratcliffe, Construction Manager on 021 315 878.

For all other queries, including to sign up for email updates as this project progress, please email engagement@wellingtonwater.co.nz with ‘Papawai Stream’ in the subject line.

This beautiful stream flowing through Prince of Wales Park is a natural channel for stormwater, which eventually runs into a pipe on Papawai Terrace. Heavier, more frequent rainfall had led to the stream bed eroding, and a lot of sediment being pushed into the stormwater network. This can create blockages in the pipes, and lead to overflows and flooding. 
 
Phase 1 works were completed in June 2025 and involved works to provide protection to the eroding streambanks prior to the network intake.

Phase 2 works are now underway. Crews from Mills Albert are setting up onsite and physical works are due to start from next week Monday 8 June. 

Works are expected to be completed in August 2026, with the scope including:

• Construction of an in‑stream gravel trap to intercept and manage sediments from the upper catchment 

• Realignment of a section of the existing bund (ca. 35-40m) to increase channel capacity, improve flood conveyance, and restore its intended flood mitigation function 

The project team is also actively working to include the extension of the bund’s full length as part of these works. We’re preparing a consent application and aim to lodge this early to mid-June 2026 as this work will not be covered under emergency works.