Flooding in Pahiatua and Tararua District, on 18 August, 2024. Photo: Supplied/ Luke Chandler
A lower North Island mayor whose district was hit hard by flooding in August says infrastructure upgrades to avoid a repeat come with a hefty price tag.
Dozens of properties in eastern Pahīatua were affected by flooding when about 60 millimetres of rain fell in the town over a few hours on 18 August.
Residents on and near Huxley Street bore the brunt of the downpour, as streets turned into waterways.
Tararua District mayor Tracy Collis said last month's flooding was fast and traumatic for those who lived through it.
The council was looking at long-term options to deal with stormwater before it reached the town, which would involve diverting water.
"There are several ways to do this, but each comes with a large price tag. It is a balance when we are required now to plan infrastructure for 200-year storm events - hair raising when what we experienced in Pahīatua was a 1-in-30-year event.
"Our weather is changing at rate we are struggling to keep up with."
The most important piece of work in the council's long-term plan was flood modelling work. Its findings would inform the plan for what stormwater systems should be build, and where, Collis said.
The Huxley Street drain and town creek had been problematic for many years. They were natural courses for water and had environmental considerations to factor in with their cleaning, she said.
"The agreed maintenance, which clears rubbish [and] vegetation, and spraying, were all carried out. The drain could not cope with the intensity and volume of the rainfall that we seem to be experiencing more frequently."
Officials would discuss the "level of service" at their next climate change and emergency management committee meeting.
She encouraged residents to help the situation by not dumping rubbish or lawn clippings in drains which could block them.