The overgrown, circular structures are built into the hillside on the R666 Lismore-Fermoy road close to Lismore Castle.
They have both separate access and a common porch entrance where connecting air-tight doors lead to the ice chambers.
The project is part of a series of joint initiatives marking Lismore’s 25th anniversary as a heritage town.
It will see the council clean the site and provide parking spaces for up to three vehicles, while the tidy towns committee will provide interpretation boards.
The ice-houses were built — probably using local limestone — by Edmund Foley, who founded the Blackwater Fishery in 1790.
Lismore Estates, on behalf of the Duke of Devonshire, purchased them in 1905 and now leases the site to Waterford Council.
The houses’ interiors are semi-accessible but the underground storage interior, which would plummet up to 8m, has long been filled to ground level for safety.
“Each house has a dome shaped roof, with their middle sections cone shaped,” said Michael McBride of Lismore Tidy Towns committee, who has researched the structures.
While a smaller ice house also stands in Lismore’s Millennium Park, the buildings are amongst the very few ice-houses still standing from an era when many of them would have been used for storing fish that was delivered along the 23km-stretch of river from Youghal to Cappoquin and beyond.
“The ice was often imported from Norway via Scotland, although winters were often very cold and a sluice trap was also designed close to nearby Cavendish Bridge to capture water, which soon froze and was carted to the ice houses,” said Mr McBride.
After the Duke of Devonshire purchased the structures, they remained in use until the 1940s.
“Ice-houses were a status symbol for the big houses who could boast of not just of having fish out of season but of having ice for their drinks!” Mr McBride said.
The preservation work is expected to be completed in May and Lismore Heritage Project manager officer Mealla Fahey said: “It will be a valuable addition to Lismore’s heritage charms and will help to enhance its place on the Ancient East tourism trail.”