The water quality of one of the world’s most pristine lakes is under threat from an increase in the number of visitors.
NIWA testing has found the water clarity at Blue Lake in Nelson Lakes National Park is among the highest in the world, with 63m visibility – almost optically pure. But senior DOC ranger Phil Crawford said this had led to a boom in its popularity and campers had been defecating near the lake and washing in the water.
“It’s incredibly disappointing that people don’t treat it with the respect it deserves,” Crawford said. “Over time, that will inevitably have an affect on water quality.”
The lake is also part of the Te Araroa Trail, which had seen a sharp rise in numbers.
The number of hut nights at the nearby 16-bunk Blue Lake Hut had more than doubled in the past two years, going from 700 to 1575. There were also regularly 10 to 15 tents pitched beside the lake, Crawford said.
In a bid to prevent people polluting the lake, a warden will be stationed there over the summer.
DOC has also created a 12-tent campsite with a cooking shelter and a new toilet to coax people away from the lakeshore.
DOC was also installing signs encouraging people to respect the lake and was working with local iwi to develop a campaign to highlight its cultural and spiritual significance.
Beyond that, Crawford said DOC was limited in what it could do.
“We can’t stop people camping – it’s a national park.”
Longterm, Crawford said it could investigate creating a bylaw to protect the lake, but that could be a drawn-out process.
“At this stage, we just hope that having a warden, a toilet and extra facilities will alleviate the issues,” he said.
If numbers continue to increase, DOC could also investigate building a larger hut.