Horizons Regional Council's Rachel Keedwell: Boosting Palmerston North's flood defences

Work is under way to realign and rebuild the stopbank at Mangaone Stream, upstream of Pioneer Highway. Photo / Supplied

OPINION:

At the end of last year, I wrote about the actions Horizons is taking in the climate change space. Today I want to talk about a project that is happening in Palmerston North to increase our resilience against flooding, which is something we are likely to see more of under climate-change scenarios.

One of the Government's shovel-ready funds made available after the first Covid lockdown was the Climate Resilience Fund. Horizons was successful in securing $26.9 million for climate resilience works on the Rangitīkei River, Foxton township, the lower Manawatū River, and for the flood protection network in Palmerston North.

The work in Palmerston North tackles a range of aspects to improve the resilience of our flood protection network. We have 26km of stopbanks protecting the city, but a stopbank is only as strong as its weakest point so it is important to check stopbanks thoroughly for weaknesses.

One comprehensive piece of work already completed is a survey of all the pipes penetrating the stopbanks using CCTV cameras. There were also investigations of other drains and the soil profiles to pick up any potential weaknesses that needed to be fixed.

Another part of this climate resilience project in the city was improvements along the Mangaone Stream. There are stopbanks along the Mangaone from upstream of Rangitīkei St to downstream of Pioneer Highway.

You may have already seen some of the work carried out on the Cloverlea part of the network, where a timber retaining wall that had passed its use-by date has been replaced with a more naturalised berm that will be revegetated with native plants.

Further downstream, work is under way to realign and rebuild the stopbank along the Mangaone Stream for the new development area of Kākātangiata. The current state of this stopbank would not be suitable for the planned houses. You can see this work from the Mangaone walkway upstream of Pioneer Highway.

More work is still needed to complete this climate resilience project, but when it is all done it should help ensure the city's defences against flooding will withstand the flood levels they are designed for.

And while talking about climate resilience, if your community group, school or marae has a project in the climate-change space, keep an eye out for our new Community Climate Response Fund – Pūtea Hapori Urupare Āhuarangi. Applications open on April 1 and up to $15,000 is available per application.

• Dr Rachel Keedwell is chairwoman of Horizons Regional Council.