District ‘better prepared’ for floods: Lessons learned from severe weather events

Tairāwhiti is better prepared for flood events, according to the findings from an external review of the region’s Flood Warning Manual.

The manual guides Gisborne District Council in the lead-up to and during a severe weather event.

It outlines clear steps on how to respond to these events, including what time to send alerts or issue evacuation notices.

Recommendations from the review will be implemented in the coming months, the council said in a media statement.

Council hydrologist and flood warning officer Divesh Mistry said it was great to have a comprehensive review of this key document.

“It is critical to community safety.”

The review, done by the National Institute of Water and Atmospheric research (Niwa), highlighted the strength and experience of the local team, Mistry said.

“After multiple weather events between 2018-2024, our team have grown and learnt a lot.”

Mistry felt this was also reflected in the Tairāwhiti Emergency Management team being recognised nationally for the work on its Common Operating Picture (COP).

“Niwa described the manual as being concise and user-focused, which is seen as a key strength.

“It is important to view the manual as a live document. Incident management is based on iterative learning, and we are all constantly improving after every event.”

The local learning was enhanced by leaning on neighbouring regions and national and international case studies to make sure Tairāwhiti’s procedures were the very best they could be, Mistry said.

“We want to be ahead of future challenges and the review will help us achieve this.

“Working with neighbouring regions can bring with it a wealth of knowledge.

“Currently, as an event makes its way down the country, local flood warning officers don’t have access to all river level and rainfall data in real time from other regions.”

Mistry said following Cyclone Gabrielle, there was increased awareness that regional councils held a wealth of data that could be used nationally to inform risk through a national-level common operating picture.

“This would collate the data from 16 regional councils and other government agencies such as MetService and Niwa.

“It is a key recommendation from the Government inquiry into Cyclone Gabrielle.

“Within our region the flood warning manual is focused on five key sites which are most at risk from severe flooding. Each of these has its own flood forecasting model.”

The council had an eText warning service that anyone living in these areas should sign up to, Mistry said.

“While we can’t model every river in the region, we can make the most use of available data from the likes of MetService forecasts, rainfall data and live river levels to make informed decisions to keep all communities safe.”

This was where information from neighbouring regions about what was happening there could potentially feed into Tairāwhiti and enable them to be a key player, Mistry said.

“We are now linking in with neighbouring rain gauges in Hawke’s Bay and starting to see national conversations on this topic. I’m hopeful that we will see a resolution to this via a national-level common operating picture in the next few years.

“But there are challenges. Our region has high rates of erosion, alongside woody debris issues. Blockages around bridges create additional challenges when modelling forecast river levels.”

Mistry said much had been gained from the Niwa review, with some recommendations in the process of being implemented — such as having more support for the on-duty flood warning officer.

“The region has six flood warning officers which will switch to four officers and four flood warning administrators to ensure depth of knowledge if people leave and for multi-day events.

“There are national conversations on this topic, with GDC tied into them. It is anticipated there will be a standardisation in flood warning manuals across the country with consistent definition of roles and responsibilities.

“Due to our experience, we have a lot of valuable feedback and hopefully will be involved with these conversations to ensure all regions can benefit from the lessons we have learned through this review and at a higher level from the events themselves.”