The transformation of Sanatorium Reserve

Surrounding the edge of Lake Rotorua along Sulphur Point, and a stone’s throw from Rotorua’s CBD, the 77ha Sanatorium Reserve has undergone a remarkable transformation. The fourth-largest area of geothermal habitat of its kind in Aotearoa New Zealand, the reserve is now a thriving ecological and geothermal sanctuary, thanks to years of dedicated restoration work. 

The journey began in 2018, led by Rotorua Lakes Council, and with Bay of Plenty Regional Council joining as a co-funding partner not long after. Together, both councils have worked to restore the reserve’s natural balance, turning the area into a thriving ecosystem for endangered flora and fauna. 

The site is classified as a Priority Biodiversity Site (PBS). These sites are areas of land (private and public) identified as containing high biodiversity values. For example, these areas may be home to rare or at-risk native species.  

In the first phase of the project, restoration efforts included extensive pest plant control, rubbish removal and clean-up activities.  

“Now in its maintenance phase, the focus has shifted to regular conservation mahi, including pest animal control and vegetation management,” explains Regional Council Land Management Officer Rob Ranger. 

“This will continue to foster the regeneration of geothermal vegetation while protecting native species.” 
The reserve is home to many endangered birds, including weweia (dabchicks), taranui (Caspian terns), tarāpuka (black-billed gulls), tūturiwhatu (banded dotterels), tarāpunga (red-billed gulls), and both kawau tūī and kawau (little black and black shags).  

“The vision is that the area will continue to be a sanctuary for the at-risk bird species that nest here. Removing pest plants means native plant species, particularly geothermal kānuka, can thrive too,” Rob adds. 

Geothermal kānuka is an indicator species: “Simply put, when this particular type of kānuka is thriving it shows that the overall health of the ecosystem is getting better. It’s like a litmus test for the area – when it does well, other species do too.” 

Recent monitoring has revealed the presence of pekapeka-tou-roa (long-tailed bat), a nationally critical species. Their presence is a promising sign.  

“If they’re breeding here, we know the mahi being done to strengthen the environment is working,” says Rob. “For example, the pest animal control we’re doing should benefit them because rats are one of their prime predators.” 

Rotorua Lakes Council Open Spaces Operations Advisor Gary Coker says he has witnessed the changes firsthand since the project began.  

“The transformation is remarkable, especially considering the years of minimal maintenance that allowed pest plants such as bamboo and wilding pines to take over.”  

Gary is excited for the future of the reserve. “Now we’re seeing native species thriving and providing habitat for invertebrates and reptiles too.” 

Beyond its environmental value, Gary notes the rich history of the area.  

“It’s a significant place, with deep connections for local iwi, including the Te Arikiroa battle site, while early Europeans flocked to the area to bathe in the thermal water, as it’s renowned for its healing properties.” 

Today, the Te Ahi Trail winds through the reserve, offering locals and tourists a unique experience – biking past steaming rocks, walking beside bubbling hot pools, and standing on moon-like geothermal landscapes. 

“There’s not a lot of places on the planet that have the plant and animal species we have here, and not many geothermal areas are as accessible as this,” says Gary.  

“It’s a special place and it deserves protection.”