Spec Creek runs through the properties of farmers Phil Smith and Hamish Mackenzie, who have fenced off the stream from stock with help from local freshwater conservation group Tiaki Maniototo.
They have also created a carpark and information panels, as well as a walking track throughout the sanctuary.
The Central Otago Roundhead galaxias are found only in the Upper Taieri and Taieri catchment and in a few streams of the Manuherikia catchment.
They are classified as nationally endangered.
The project was dedicated to the late Matt Hickey, a water scientist who worked to protect Otago’s waterways.
Speeches were held in Mr Smith’s packed woolshed before the information panels were unveiled.
Mr Mackenzie said the project’s origins stretched back 20 years ago to when the galaxiid population was identified in Spec Creek.
"We all just thought they were just little minnows. We didn’t realise how threatened they were."
Pupils from St John’s School got a chance to view the endangered fish at the unveiling.
It was important future generations understood the significance of freshwater conservation, Mr Mackenzie said.
A key aspect of the project was the long-term water consent granted by the Otago Regional Council, he said.
"Environmentally, there’s a lot going on in rural New Zealand about protection and ... regulations.
"Everyone’s got a creek that runs through their farm and you do actually have to fence a lot of them off now," he said.
Mr Smith, a fourth generation sheep and beef farmer, said the goal of the sanctuary was to teach people about the galaxiid population.
"We just really wanted this to be an educational centre and highlight the risk we have of losing these precious wee galaxiid fish."
There was ongoing work to protect the galaxiids from invasive fish by installing fish barriers and he also hoped to further develop information panels on the site, he said.
The project was a fitting tribute to the late Mr Hickey, who was instrumental in securing the water consents for the area, Mr Smith said.
"He managed to get all the farmers in Kyeburn together and singing off the same hymn sheet."
Mr Hickey had incredible people skills and keen scientific mind, Mr Smith said.
"He was just a hell of a good guy ... This is just a very small tribute to what Matt was actually worth to us in the Kyeburn catchment."
Tiaki Maniototo is a project group that received funding from the Ministry for the Environment’s freshwater fund.
