Waitaki Mayor Alex Familton has dismissed the research, saying the region has never been better poised for growth.
The Waitaki district is one of two South Island regions with a stagnant or declining population, a recent study shows.
But Waitaki Mayor Alex Familton has dismissed the research, saying the region has never been better poised for growth.
The study was carried out by Waikato University researcher Natalie Jackson and summer research scholarship student Dave Greenslade, who collected and analysed information from Statistics New Zealand to examine the triggers for decline.
They said the figures were part of a worsening decline, as the older generation died off and young people were leaving.
Fifteen districts across the country, including Waitaki and Gore in the South Island, have been listed as having either stagnant or declining populations of young adults, with a notable loss of women in the fertile age range.
Ms Jackson said the study was designed to provide an evidence base for the affected authorities.
Data was still being assessed and each area tended to have different characteristics.
However, a common theme was the significant deficit of young adults, Mr Greenslade said.
He said young women, in particular, were moving away and not returning.
"Not only do you lose them, but you don't get the children they may have," he said.
Mr Familton agreed more needed to be done at local and central-government level to give young adults opportunities, but he said there was a "raft of activity" planned for the Waitaki district leading up to 2020.
"I can say with some confidence that those predictions are quite unrealistic," he said.
"What Waikato University won't have taken into account is the impact that all of the projects we have lined up will have on the region." Those projects included a 312km cycle trail through the Waitaki and Waiareka Valleys to Oamaru Harbour, to be completed in two years; Meridian Energy's North Bank Tunnel,
set to start construction in 2015; and the development of the town's new business park.
He also mentioned opportunities arising from Macraes Flat gold mine and the development of Oamaru's historic precinct.
"Most of those things will eventuate, and job opportunities will not only keep young people in the region, but draw new people in," he said.
In October last year the council was presented with a report predicting Oamaru's population (21,217) would rise to 21,360 in 2021, but then drop to 20,453 by 2036.
New Zealand's ageing population was also expected to affect the Waitaki district, where the number of residents aged over 65 was forecast to double from 20 per cent (2008) to 40 per cent in 2036.
Visitor numbers were predicted to increase slightly, with an additional 4500 people estimated by 2036.