The Oparara Basin, in the Kahurangi National Park and just north of Karamea, is regarded as one of the most outstanding limestone karst landscapes in New Zealand.
A $5.7 million government grant from the provincial growth fund, announced in 2020, has been put to use in the area for the past three years, including the gradual upgrade of the 16km narrow road into the valley.
The road was originally built in the 1960s for one-way logging traffic.
Some aspects of the Oparara redevelopment have not been without controversy.
This includes a 65m-long cantilever structure through the fragile karst landscape, originally proposed but then dropped in 2021 following an outcry about the impact on the site from environmental groups Forest and Bird, and Federated Mountain Clubs.
Department of Conservation (Doc) Western South Island director Mark Davies advised the West Coast Conservation Board last month that the department was again pulling back the scope of plans for the site.
This was specifically related to an ambitious viewing platform intended for the middle of the site.
"We have worked through that whole process ... really, the geology of the site, of the very weathered limestone, is not going to allow the department to construct what was planned," Mr Davies said.
A geotechnical investigation for the platform could not find suitable foundations to anchor it.
The department would work through the issues with the Oparara Valley Trust, he said.
The decision to revise the scope of the project, however was "a bit disappointing".
"But nature is not allowing."
Overall improvements to the area include a 300m loop walking track extension, and a full upgrade of the existing Oparara walk, improvement to the Mirror Tarn viewpoint, and the Oparara Arch Track.
This work had been done in keeping with the karst landform of the area — built by hand, with all hard material manually carted to the site, Mr Davies previously said.
Pre-Covid, Oparara Basin was attracting between 20,000 and 25,000 visitors a year.
By Brendon McMahon
