Brookfields Lower stopbank upgrade

The 2km stretch of stopbank runs along the Tūtaekurī River, from just past Brookfields Bridge down to the SH51 bridge. The stopbank sits on the river’s true left (Meeanee and Awatoto side).

During Cyclone Gabrielle, the Awatoto area suffered severe flooding from significant inundation and a stopbank breach. While emergency repairs restored it to the previous regional standard of 1% Annual Exceedance Probability (1% AEP), post-Cyclone the flood models have been revised and this section now fall short of the standard.
The jointly funded NIWE programme has given us the opportunity to upgrade the stopbank for this area which will help better protect local homes, businesses and infrastructure – and give people more time to act when the next major storm hits.

• Raising and strengthening a 2km section of stopbank on the true left (North bank) of the Ngaruroro River (from the Brookfields bridge to SH51 bridge)
• Reshaping the riverside slope – or batter – to meet current best-practice design standards.
• Reviewing vehicle access ramps to reduce erosion risks and overtopping during floods.

We are working through the Resource Consent requirements. We expect construction to begin by June 2026 and finish by December 2026.

A scheme is the network of stopbanks, pump stations, floodgates, plantings and other works that reduce flood risk in a particular area. Each scheme is built to an agreed regional standard or ‘level of service’ – the performance standard it is designed to deliver.

In flood control, this is usually expressed as the size of flood it can manage, such as a 1% AEP event. Over time, that standard can be reduced by climate change, earthquakes, or changes in the riverbed. A level-of-service upgrade restores the network to its agreed benchmark – and at times raises it beyond.

1% AEP = there is a 1% chance of an event that size happening in any given year.

It’s a probability not a predication, so they can, and do occur more than once in 100 years.