Upgrade to reduce flood risk

A crucial culvert upgrade is well underway at the northern entrance to Pukekohe.

Auckland Council Principal Delivery – Special Projects manager Leighton Gillespie said the
Paerata Road culvert needed to be replaced to reduce flooding for residential and industrial
properties close to Hickeys Recreation Reserve.

“Starting in April 2024, council’s Healthy Waters department is replacing the culvert with a 12-metre-long bridge over Whangapouri Creek to replace the existing 1.5m culvert.

“This is to improve floodwater management and enable the stream to flow more freely. In
addition to the bridge, we are implementing erosion protection and slope stabilisation along the stream banks to enhance resilience.”

Gillespie said the upgrade will increase stormwater capacity, ensure better management of future climate conditions, and accommodate additional flood mitigation measures upstream.

It forms part of a wider stormwater improvement programme aimed at reducing the floodplain and supporting growth in the area. The estimated cost of the project is $15 million.

“We are now doing the downstream works to widen and stabilise the slopes and help water
around the bend at the confluence area by installing instream features.”

The project was expected to be completed in spring but has been delayed due to underground services and diversion approvals, which are now resolved.

“However, it delayed us through the dry weather period,” Gillespie said.

“The project has been in the works for many years and was established due to catchment
modelling and identifying pinch points in the system. Modelling showed overtopping of the road during significant rainfall events, causing widespread flooding upstream and to the north of the site.”