It means another frustrating delay for Dunedin Tunnels Trail Trust member Gerard Hyland, who is pushing for the reopening of the Caversham and Chain Hills tunnels to cyclists and pedestrians.
"Having yet another delay is extremely frustrating," Mr Hyland said.
"The council is understandably reluctant to commit to any major spend, so what the trust needs to do is show that there is strong community support for this to proceed."
The former Caversham rail tunnel was used by cyclists and pedestrians after 1910, but was closed by the council in 2006, due to safety concerns about water, sewerage and gas pipes, and electrical cables.
Mr Hyland has been at the forefront of the campaign to have the tunnel reopened to cyclists and pedestrians, and is a member of a Dunedin City Council working party investigating the tunnel's reopening.
In its annual plan deliberations in May, the council committed $100,000 to start work on reopening the tunnel, with any further funding to be considered in 2012-13. This was on top of $30,000 budgeted for a geotechnical report.
Testing gas levels in the Caversham tunnel is an important part of the investigation and gas-monitoring equipment was was installed and was supposed to run from October 20 to November 23. However, the equipment failed after just 23 hours.
During that short period it showed a reading consistent with fresh outdoor air.
Wind-speed monitoring equipment did function during the month, and showed that the entire air volume of the tunnel was purged every 18 minutes.
"It was heartening to see even the preliminary results show a good flow of air through the tunnel, as most people who have walked through the tunnel previously could attest," Mr Hyland said.
Contacted by The Star, council water and waste network maintenance manager and fellow working party member Mike Ind said replacement gas-monitoring equipment would be fitted in the Caversham tunnel this week to repeat the month-long measuring programme.
The equipment was owned and operated by a contractor, so there would be no additional cost to the council, he said.
"It does result in a delay in terms of analysing the results," he said.
Contacted by The Star, Dunedin City Councillor, working party member and tunnel supporter Kate Wilson said the delay was regrettable.
However, it was important to focus on safety, she said.
Mr Hyland had gathered a lot of good people who were "ready to go on the project" and she was "pretty positive" about the project.
Community support for the reopening of the tunnels was strong, as it would create a flat, safe cycle route, which would not only be good for commuters, but could be a "crown jewel" of Dunedin tourism, Mr Hyland said.
If both the Caversham and old Chain Hills tunnels were opened, there would be a flat route right through Dunedin from Aramoana to Henley, Cr Wilson said.
"It would be a wonderful way for people to enjoy the city and would be a great way of getting cyclists off the roads," Cr Wilson said.
Mr Hyland planned to start a non-binding pledge register, via the trust's website www.cavershamtunnel.org.nz, to ask individuals, groups, organisations and businesses to indicate what support they could offer the development.
"By showing the council that this truly is a community-based initiative, it can be moved from the list of future 'nice-to-haves' to something that can be achieved soon without committing funds from already-drained budgets," he said.
