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Ngātea stopbank upgrade

Topping up stopbank level

Stage 3 works begin

We’re raising the height of 1.7km of stopbank – from 209 River Road to the Ngātea town bridge. This work began on Monday 15 January 2018 and is expected to take 42 days, but is weather dependent.

Construction will result in 80-100 truck movements daily between 7am and 7pm, 6 days a week.

As a result of our work, trees still standing on the stopbank will be removed. That's because trees growing on stopbanks can affect the integrity of this vital infrastructure.

The last step as construction moves along the bank is for hay mulch to be applied. This will protect the surface of the stopbank and allow the new grass to grow.

Why we’re doing it

Currently all stopbank heights (pre top-ups) are above the desired flood design level. This top-up is to provide a ‘freeboard’ of 500mm above the flood level. Stopbanks naturally sink over time, so the freeboard also allows for this without reducing the service level to the community.

Ngātea and the surrounding area on the Piako River is vulnerable to flooding. This project – which started in 2008 – will help us provide continued protection to people, land and roads as part of the Piako flood protection scheme.

The final stage of the project will take place in January/February 2019. It will involve upgrading 1.1km of stopbank from the Ngātea town bridge to the Phillip Island Rd bridge.

Sorry for the disruption

We’re working with our contractors – Kerepehi Transport Ltd – to minimise the impact of our works on Ngātea residents. But, at times, you might experience:

  • traffic disruptions on River Road
  • construction noise and vibration
  • restricted or no access to the walking track.

Timeline: A four stage project

2008-2015        Stage 1: Bank stability – extend the berm width to 13 metres
2016 Stage 2: Upgrade stopbank opposite Ngātea township
Summer 2018 Stage 3: Upgrade 1.7km of stopbank – 209 River Rd to Ngātea town bridge
Summer 2019    Stage 4: Upgrade 1.1km of stopbank – Ngātea town bridge to Phillip Island Rd bridge


A section of the Ngātea stopbank

A section of the Ngātea stopbank

About the flood protection scheme

The existing Piako flood protection scheme was developed by the Hauraki Catchment Board in 1959 and constructed between 1962 and 1979. The scheme provides vital river and coastal flood protection for a significant portion of the Hauraki Plains.

The Waihou-Piako flood scheme

  • 986km of rivers
  • 343km of stopbanks
  • 134 floodgates
  • 52 pump stations