Queenstown Lakes District Council emergency management officer Brenden Winder said in a typical year there may be two or three call outs a month.
"Currently we are getting three or four a week, so it's quite a dramatic increase," he said.
The call outs are about evenly spread between Wanaka and Queenstown.
The latest came yesterday with reports of a substance, probably turpentine, in Horne Creek.
Mr Winder said he was not aware of any significant fish or wildlife deaths being reported as a result of the pollution.
"But it can't be doing them any favours; fish do spawn in these creeks, so there is concern for the really fragile wildlife."
Horne Creek, which runs out of the Gorge Rd area but has lots of small tributaries, also collects storm water from all parts of Queenstown, which eventually runs into Lake Wakatipu.
"Occasionally it [the pollution] is visible from the Skyline [gondola] area so that's not a good look for visitors to the town. It also runs right through the middle of the Village Green so that's a highly visible part of town; it's not ideal," he said.
Identifying those responsible for the pollution, however, was not easy. Both the QLDC and the Otago Regional Council had attended each reported incident in the past six weeks but had so far been unable to pinpoint the perpetrators.
QLDC harbourmaster Marty Black, in a press release issued yesterday, said incidents such as paint being washed into the storm water system, which in turn discharges into the creeks, was often due to "ignorance or sloppy contractors", but polluters and their employers needed to understand they faced prosecution and the full recovery of cleanup costs.
There had been a number of notices issued, he said.
There was a recent incident in Gorge Rd involving about 60 or 70 litres of diesel but he did not want to go into details as the matter was still under investigation.
Mr Black said he did not know why there had been an escalation of incidents lately.
"It goes through cycles; people just get lazy," he said.
Mr Winder said the QLDC was keen to hear from any member of the public who observed anything suspicious.
"We are more than happy to investigate any potential pollution report; it's critical the community and the council act to protect these precious resources."
• Pollution calls can be made directly to council customer service advisers at Wanaka (03 443 0024) or Queenstown (03 441 0499).
