Pinehaven Stream Improvements

Work to upgrade two culverts within the Pinehaven Stream that form the road crossings on Sunbrae Drive and Pinehaven Road was completed in early 2022. The Phase 1 works included:

• Replacing the existing culverts with larger culverts and headwalls that meet current seismic and roading standards
• A new roundabout at the Pinehaven Road/Blue Mountains Road intersection
• New footpaths, fencing and planting.
• The removal of 48 Blue Mountains Road and 4 Sunbrae Drive. This property was identified as  flood prone during investigations into flood protection and GWRC acquired it as part of that project.
• After the removal of the house the land was levelled and grassed as a temporary measure before the Phase 2 works start.

Read more here

Phase 2 stream improvements, funded for $5 million, will begin in 2023 in the Willow Park area immediately downstream of the Phase 1 works and will include:

• Widening the section of stream through Willow Park from Sunbrae Drive to Blue Mountains Road.
• Building new retaining walls immediately downstream of the Sunbrae culvert.
• Widening the stream banks (without retaining walls) further downstream, where there is more space available.
• Removing the existing pedestrian bridge over Pinehaven Stream at Willow Park and replacing it with a new pedestrian and cycle bridge linking to 4 Sunbrae Drive.
• Improving the pedestrian path through Willow Park.
• New and replacement planting of native trees and plants.
• Upgrading the junction where Pinehaven Stream joins Hulls Creek (by the Silverstream Railway Station) to make it easier for fish and eels to travel between the two watercourses

The Pinehaven Stream Upgrade is a long-term project aimed at reducing flood risk and improving stormwater resilience in the Pinehaven area.

After completing the Willow Park section of the works, Upper Hutt City Council and Greater Wellington Regional Council took back project management responsibilities from Wellington Water. They are now reviewing the next phases of the project to assess whether the original design is still the most effective and cost-efficient option moving forward. 

The review found that the cost to complete the remaining stages has increased significantly—from an original estimate of $10.9 million to around $58.6 million. About $22.5 million has already been spent, and completing the rest would cost approximately $36.1 million. 

The remaining work is being reviewed, with the current proposal primarily focusing on activities on private properties, including the replacement and removal of access bridges and concrete channel upgrades. 

Potential alternatives include: 

• Current design option – complete the design that was originally agreed to. This   design includes significate work in the existing channel with the use of large concrete structures to keep the stream within the channel in the event of flood events.  This will require a number of new stream crossings to allow for property access. 
• Naturalisation of the channel – remove many of the existing structures and bridges that currently constrain the flow in storm events and widen the channel to increase the capacity of the stream.  This would involve significant earthworks and planting.  It may also include the targeted purchase of property to facilitate the work.
• Maintenance and clearance – undertake vegetation clearance and channel clearing to improve the flow of flood water in the existing channel.  This option would involve less initial work, but ongoing work to maintain the stream 

• Current design option – complete the design that was originally agreed to. This   design includes significant work in the existing channel with the use of large concrete structures to keep the stream within the channel in the event of flood events.  This will require a number of new stream crossings to allow for property access. 
• Naturalisation of the channel – remove many of the existing structures and bridges that currently constrain the flow in storm events and widen the channel to increase the capacity of the stream.  This would involve significant earthworks and planting.  It may also include the targeted purchase of property to facilitate the work.
• Maintenance and clearance – undertake vegetation clearance and channel clearing to improve the flow of flood water in the existing channel.  This option would involve less initial work, but ongoing work to maintain the stream 

Wider public consultation will be undertaken in early 2026 once the feasibility of the options has been determined.  

A Pinehaven Steering Group has been re-established, made up of representatives from: 

• Upper Hutt City Council 

• Greater Wellington Regional Council 

• An independent project manager 

This group will meet monthly to evaluate and guide future options. Its work is overseen by the Te Awa Kairangi/Hutt River Valley Subcommittee. 

Updates will be posted on the Upper Hutt City Council’s Pinehaven Stream Improvements webpage. A dedicated email address (pfm@uhcc.govt.nz) is also available for community questions. 

We understand this pause may be frustrating for residents still at risk. The current focus is on finding a solution that effectively manages flood risk while ensuring long-term value for the community. 

A preferred approach is expected to be identified within the next 12 months after thorough assessment of all alternative options.