Critical Hutt Valley stopbank work starting this summer

A contract for raising the existing stopbank between Melling Bridge and north of Mills St has been signed with AECOM and Fletcher Construction.

Greater Wellington Chair Daran Ponter is delighted that work to provide significant flood resilience is getting underway.
“This section of the river has the highest risk of flooding along the entire river corridor, so we’re thrilled to get this part of the project underway. There have been some sleepless nights worrying about the risk around this section of the river.

“Recent flooding events across New Zealand show it is vital we invest in flood protection infrastructure to help prevent devastating consequences for communities. It is a great relief to have this starting.” Mr Ponter says.

The team will work closely with residents and businesses near the stopbank site to ensure disruption is minimised while construction is underway.

Lower Hutt Mayor Campbell Barry supports the work being a priority.
“It will ensure residents and businesses in our community are protected from the impacts of flooding. It provides them with certainty and peace of mind.”

Waka Kotahi Director Regional Relationships, Emma Speight says the contract also includes enabling works required around Melling to allow the building of the new Melling interchange with State Highway 2.
“The contract lets us start this enabling work early and will help the main construction at Melling be delivered more seamlessly.”

Te Awa Kairangi Acting Programme Director Matt Trlin says Te Awa Kairangi partners  are pleased to see construction begin.
“It’s an important first step towards the wider programme of work. The construction team is expected to be on site for set up from February 2024, and the stopbank design will be finalised in late March.

“With regard to progressing the wider programme of work, the proposal submitted by Te Awa Kairangi Alliance is not currently affordable. This is not unusual for this stage of such a large and complex project.
“As a result, the partners have agreed to extend the timeline for the Interim Project Alliance Agreement (IPAA) to be finalised, with an update to be provided in late March. This will enable the partners and the Alliance to rigorously consider every aspect of design and scope, to agree an affordable project that represents good value for money.
“Recognising this will involve commercial negotiations between the parties, we will not be commenting further until that time,” Matt says.

More Information:

• Te Awa Kairangi ki Tai - Lower Hutt is the most densely populated flood plain in New Zealand. It has a history of flooding that led to the construction of the existing stopbanks. Climate change means flooding is likely to be even more challenging in the future.
• The new stopbank will be largely in the same location of the existing stopbank but will be approximately 1.5 metres higher, allowing more water to pass safely during floods. It will also provide flood protection during the subsequent construction of new bridges as part of the wider Te Awa Kairangi project.
• It also includes some enabling works required around Melling to allow the building of the new Melling interchange with State Highway 2. This will streamline the work around Melling interchange as part of the Te Awa Kairangi project.
• Once underway the construction of the stopbank is expected to take 6 months to complete.
• The existing stopbank between existing Melling Bridge and Mills Street currently has the lowest level of flood protection in the area, with only 1 in 65 year flood event protection.
• When all of the works under Te Awa Kairangi programme are completed, the Hutt Valley will be protected from a 2,800m3/s flood (approximately 1 in 440 year flood event including for future climate change).
• As well as recognising the significance of Te Awa Kairangi / Hutt River to iwi Taranaki Whānui ki Te Upoko o Te Ika and Ngāti Toa Rangatira, the historical settlement of Maraenuku Pā is in the vicinity of the Connelly Street Substation.
• The status of the broader programme for Te Wai Takamori O Te Awa Kairangi remains in an Interim Project Alliance Agreement (IPAA) phase.
• The IPAA phase involves a detailed review of every element of the consented design, and improving the design where feasible, to allow the partners and Alliance to agree the scope and confirm a price to deliver the project.

Note: Te Wai Takamori o Te Awa Kairangi – The Soothing Waters of Te Awa Kairangi – is a partnership of iwi Taranaki Whānui ki Te Upoko o Te Ika and Ngāti Toa Rangatira, Greater Wellington, New Zealand Transport Agency – Waka Kotahi and Hutt City Council.