The Southern District Health Board plans to close Dunedin's physiotherapy pool to avoid a major upgrade.
The 68-year-old heated pool in the central city was the first in New Zealand to be purpose-built for rehabilitation and is a category 2 historic place.
The pool is used by 20 community organisations and gets 40,000 visits a year.
The DHB says it has to close the pool in December this year, because it can not afford a $1 million upgrade needed, nor justify spending $100,000 a year maintaining it.
Southern DHB's patient services director Lexie O'Shea said on Wednesday that it has been a hard decision but the pool is well beyond its economic life.
Physiotherapist Andrea Mosley has been using the pool to rehabilitate seriously injured people for more than 40 years and said the decision is terrible.
"It's disastrous - this is the pool jewel of Dunedin. And in terms of a rehabilitation facility, it just can't be duplicated.
Ms Mosley said the pool may be old, but it is vital to the recovery of thousands of people and she shudders to think what will happen if it shuts.
Pool users and physiotherapists have vowed to fight the closure.