Second phase of Pinehaven Stream upgrade gets green light

Published on 28 November 2022

The next important phase of the Pinehaven Stream upgrade is set to begin in early 2023 with project details now confirmed.

Phase 2 stream improvements, funded for $5 million, will begin in March 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.

Greater Wellington Flood Protection Manager, Graeme Campbell, said the Pinehaven Stream has a long history of flooding and this work to increase stream capacity will reduce the risk of homes flooding in the Willow Park area.

“The aim of these improvements is to ensure that during a significant flood event, which will have a 4% chance of happening in any given year, floodwater stays within the stream banks. Additionally, during an extremely significant flood event, which has 1% chance of happening in any given year, flood water does not impact the inside of homes in this area.

“The Willow Park section of the Pinehaven Stream was chosen for Phase 2 works, as stream widening here will provide significant flood protection benefits without increasing the risk of flooding in other areas.”

Upper Hutt City Council’s Director of Asset Management and Operations, Geoff Swainson, said that as well as funding already committed to Phase 2 stream improvements, both councils were working together to secure additional funding for future stream upgrades.

“We know the Pinehaven community will be pleased to see this next phase of work underway as we work to progressively increase the capacity of the stream and we hope to provide an update on future funding for Phase 3 works in the coming months.”

Wellington Water will be working closely with affected residents and property owners over the coming weeks to confirm Phase 2 plans and discuss the detail of the process.

The Pinehaven Stream upgrade is a phased programme of works set out in the Pinehaven Floodplain Management Plan, with these works being delivered by Wellington Water on behalf of Greater Wellington and Upper Hutt City Council to upgrade and increase the capacity of the Pinehaven Stream to reduce flood risk to the surrounding area.

Phase 1 work was undertaken between May 2021 and June 2022. It included replacing the Pinehaven and Sunbrae culverts, reinstatement works, and the removal of two houses.

Photo: The completed Sunbrae Drive culvert constructed during Phase 1 works.

For more information on the Pinehaven Stream project, go to wellingtonwater.co.nz/pinehaven-stream-improvements/