An investigation of water quality on the Clutha River was conducted after the Otago 4WD Club Superwinch Mainland Challenge, held on Saturday, July 7.
Otago Regional Council (ORC) senior environmental officer Simon Beardmore said the ORC conducted a thorough investigation of the site after receiving a complaint.
Central Otago 4WD club treasurer Brent Wilson said no mud went into the river after the event.
“The biggest issue from our perspective is avoiding all run-off, so any run-off is captured within the grounds that we have.”
The competition route had been devised so it was at least 30m from the river edge, but competitors transitioning between stages “would have been travelling within 5m of the river edge at two places. We had barriers and tapes and warnings up”, Mr Wilson said.
Mr Beardmore confirmed there were no sheens or oily residue noted in any of the puddles or surface water surrounding the challenge location, nor were there any conspicuous changes of colour or clarity of the Clutha River.
“Water was observed up and downstream of the site, from the Clutha Dam to the slalom course on the Clutha River in Earnscleugh, and was found to be of the same colour and clarity as the challenge site.
“Therefore it was determined that no rules within the Regional Plan: Water for Otago had been breached during the Otago 4WD Club Superwinch Mainland Challenge,” Mr Beardmore said.
However, local parent Lynne Stewart, of Earnscleugh, said the Ngapara pools, near the Clutha River, were “dug up and left a mess” by the event.
Ms Stewart and other volunteers had conducted extensive native planting on the opposite river bank from the pools.
She suggested that if the club was conducting events near the river, its members could plant natives, including flax and cabbage trees, which would provide habitats for native birds and also filter runoff from the event before it entered the river.
The club would consider planting natives, but its lease did not allow planting, Mr Wilson said.
Land Information New Zealand (Linz) deputy chief executive for Crown property Jerome Sheppard confirmed the club would need to ask permission from the commissioner of Crown lands to carry out planting, but had not received any communication from the club.
“If they do want to apply for permission then we will be more than happy to discuss with them what plants they are considering, the location and what will be best for the future of the land,” he said.
“We have in the past given permission for native plantings on other areas of Linz-owned land.
“We look forward to hearing from them on this issue and working with them to ensure the land is cared for in the best way possible for generations to come.”