Wanaka residents and visitors are all doing their bit to keep green the new grass runway at the town's airport.
A $170,000 irrigation system installed over the past 18 months takes water from the Queenstown Lakes District Council Project Pure wastewater treatment plant and applies it to a 950m by 30m strip of grass running the length of the airport.
Airport manager Ralph Fegan said yesterday the grass was sown in November and was growing well, helped along by nutrients in the UV-treated water.
"The grass has got a really good, strong, dark green colour at the moment.''
Mr Fegan said there had been a bit of a smell with the water at times over Christmas, when Project Pure was running at its peak, but the smell was disappearing.
"Normally, when it's going, the water's dead clear without any smell at all.''
He believed it was the first time in New Zealand treated wastewater had been used to irrigate a runway.
Mr Fegan said it had taken him about five years to get the system operating.
The Otago Regional Council had been very keen for the system to be installed, so the treated water was recycled, rather than just allowed to run away underground, he said.
"So, it's a win-win for the Project Pure plant and also for the airport.''
Mr Fegan hoped the runway would be ready for use for the Warbirds Over Wanaka Airshow at Easter.
"It may be partially used for Warbirds.
"It just depends on the weather between now and then as to how it hardens up.''
The new runway had 15m strips down each side that were not irrigated, Mr Fegan said.
Once the new runway was fully commissioned, the existing, non-irrigated, grass runway that "looks like the Sahara Desert'' would be closed, he said.
The new runway is between the airport's main, sealed runway and a newly developed helicopter training area further north towards the Clutha River.
"So we can have three different things going on at the same time, which will be great,'' Mr Fegan said.
He is offering community groups the opportunity to receive a "sizeable donation'' in return for about six hours of picking up rocks from the new runway.
