Tarawera Awa Restoration Strategy Group has endorsed a project to create silica sinter terraces in Kawerau, reminiscent of the Pink and White terraces destroyed by the Tarawera eruption in 1886.

The project is an aspiration of Ngāti Tūwharetoa Bay of Plenty Settlement Trust, which plans to create the terraces along with hot pools as part of a geothermal power plant project.

The iwi sought endorsement in principle for lodgement of a resource consent for the project at a meeting on Wednesday.

Restoration strategy group chairman Leith Comer said Ngāti Tūwharetoa’s plan sounded “pretty exciting,” and he wished them well with the project as it went forward through the consenting process.

The restoration strategy group is a co-governance joint committee of Bay of Plenty Regional Council established to support, co-ordinate and promote the integrated restoration of the mauri of the Tarawera Awa catchment under the Ngāti Rangitihi Treaty settlement. It has membership of all four iwi that have interests in the Tarawera catchment area, as well as Whakatāne, Kawerau and Rotorua Lakes district councils.

The meeting agenda included a project brief for “Geothermal Pools & Habitat Re-creation in the Kawerau Geothermal field”.

The project to build a new geothermal power plant from which it proposes to utilise geothermal fluid run-off for a hot pool project has been raised at previous meetings of the restoration strategy group this year.  

Silica sinter terraces, formed from build-up of minerals from cooling geothermal run-off, are a feature of geothermal pools throughout the world, the largest of which is reported to be the Pink and White Terraces that were destroyed in 1886.

While those terraces had formed naturally over hundreds of years, projects to recreate terraces by allowing hot geothermal fluid to flow over a series of prefabricated terraced pools have been successful, such as the manmade terraces at Wairakei in Taupō.

The brief states that Ngāti Tuwharetoa ki Kawerau has land holdings in proximity to existing geothermal areas that could be suitable for this.

“Geothermal fluids available for release at the Ruruanga site contain dissolved silica and calcium in quantities that would probably contribute to sinter formation by precipitation as post-release flows cool,” the brief states.

The project brief also includes an “attractive bath complex” that utilises the geothermal fluids.

“This could be situated close to the sinter terrace, to incorporate that feature as a backdrop to the baths but also to capitalise on the temperature of geothermal fluids flowing out of the sinter terraces.”