Flood modelling hui at Te Karaka this Saturday

Robert Winiata of Te Karaka, in the aftermath of Cyclone Gabrielle. File picture by Rebecca Grunwell

Gisborne District Council is holding a hui for residents of Te Karaka and surrounding areas this Saturday to present and seek validation on flood modelling being undertaken as part of the Te Karaka Flood Resilience Improvement Project.

Council regional river manager Joss Ruifrok says the hydraulic model to be presented to the community is partially calibrated and closely replicates the sequence of flooding that happened during Cyclone Gabrielle.

“Seeking community validation is an important step in refining the accuracy of the model. Once we have confidence in the Cyclone Gabrielle event model, it will be used to understand the future flood hazard and risk to life at Te Karaka.

“We can then look at what options there are to modify the flood protection scheme and increase the level of flood resilience to the Te Karaka township.

“The modelling work is complex and has taken several months to get to the point where it can be shared with the community for validation.

“We are asking for the Te Karaka community to share details with us such as the flood height and speed of flood waters at their properties, including the exact time this occurred. This information will then be used to improve the accuracy of the model.”

Mr Ruifrok said it was not a “quick fix” project.

Once a calibrated model has been completed, option assessment work will start to understand the effects (positive and negative) of several upgrade options.

Option assessment work will be followed by formal consultation, resource consenting, detailed design, land access/purchase where required and finally the construction stage.

It is anticipated the council will be ready to commence physical works in 2028/2029, possibly earlier.

“While I appreciate the community is keen to have flood control schemes implemented quickly, we need to ensure we carefully plan improvements so we can deliver the best outcomes around flood resilience for the Te Karaka community.”

The creation of the Te Karaka hydraulic model is part of the wider Flood Resilience Investigation Programme of work happening across Tairāwhiti following Cyclone Gabrielle.

“A hydraulic model of the Taruheru catchment is also being developed, which will be used to inform engineering work to widen parts of the Taruheru River to reduce the effect of severe floods on the community and improve drainage.

“Also in development is a funding application to cover a programme of investigations, feasibility studies and hydraulic modelling work from Tikitiki to Te Arai. This will enable us to understand risks and solutions in urban and rural areas, and make informed decisions.”

The hui is being held at Te Karaka  Area School from 9am to 3pm.

In addition to the flood modelling presentation, councillors and staff will be available to converse with the community on the 2024-2027 Three Year Plan.

It is one of a series of community conversations being held around the region to ensure the community can understand and ask questions about the council’s budget and plan for the next three years.

To find out where a community conversation is near you, check the calendar of events online at bitly.ws/3gguk