Rockabilly Gully is on track to receive a new stormwater basin years after the Otago Regional Council (ORC) issued an abatement notice.
Wānaka-Upper Clutha Community Board chairman Simon Telfer said there was still some historical angst around the area.
‘‘The community is now paying for the remediation of some consenting issues.
‘‘It’s upsetting and frustrating, it’s been around for a long time, it has been compromised, we’ve all got photos of where the sediment flow has gone into the Mata-Au [Clutha River],’’ he said.
The Rockabilly Gully is in the Hikuwai Reserve between Wānaka and Albert Town.
The wider stormwater catchment includes Hikuwai, Northlake and Allenby Farms which stretches over 290ha.
A project report presented to the community board this month updated the board on ‘‘a longterm stormwater management solution that mitigates erosion’’ in the gully.
The project would improve how stormwater enters and flows through the Hikuwai Reserve and into the Clutha River.
And it would ensure compliance with the regional council’s rules, it said.
The report said the Queenstown Lakes District Council’s preferred solution included major modifications to the existing basins.
The work would divert smaller, more frequent flows from the Northlake development into the Hikuwai basin.
It would significantly increase the storage in the Hikuwai basins to more than three times the storage of the existing basin.
And it would change the design of the outlet to the gully to change the way the basins operated — ‘‘to hold back stormwater in more frequent events and release it slowly to the gully’’ — the report said.
In October 2021, the ORC issued an abatement notice requiring the QLDC to address the erosion in the gully and sediment entering the Clutha River (Mata-Au).
The report this month said the project was now to be delivered in two parts.
Construction of the new stormwater basin was anticipated to begin in June, it said.
‘‘Gully remediation, this element of the project requires a more complex consenting pathway including landscape and ecological assessments, physical works are anticipated to commence late 2026/early 2027,’’ it said.
The report said there was existing erosion in Rockabilly Gully which was progressively getting worse.
The work would change the way the gully functioned ahead of future development but would not restore the natural flow pattern, the report said.
Department of Conservation (Doc) Central Otago operations manager Charlie Sklenar said QLDC had proactively kept Doc informed of progress on the Rockabilly Gully Erosion Remediation project.
‘‘Currently, the stormwater runs through the Hikuwai Reserve, predominantly through the Rockabilly Gully — an ephemeral watercourse.
‘‘This has caused damage to shared use walking and biking tracks in the reserve, particularly a section of the Hikuwai Loop Track, at the top of the gully, and the Outlet track, at the bottom of the gully adjacent to the Clutha River.
‘‘Doc will continue to engage on the project’s progress as it moves through to the next phase,’’ she said.
ORC compliance manager Simon Wilson said the abatement notice was still in effect.
The notice required QLDC ‘‘to cease the discharge of stormwater from its stormwater network on to the Hikuwai Reserve and into the Clutha River /Mata-Aū’’.
‘‘In circumstances which cause erosion, land instability, sedimentation or property damage on land within the Hikuwai Reserve and stormwater, after reasonable mixing, creating a conspicuous change in the colour or visual clarity of the water in the Clutha River /Mata-Aū.’’
