Rotting weed leaves ‘rancid’ smell at lakefront
Clean-up begins after stormy weather washes weed onshore
Rotorua’s lakefront has been blanketed by rotting lake weed, with one passerby calling the odour “rancid”. Recent stormy weather has washed ashore swathes of the now decaying weed, similar to the 2022 incident that resulted in 300 tonnes of it removed costing ratepayers $35,000.
That is the equivalent of about 60 Asian elephant males.
Local Democracy Reporting went down to the lakefront and spoke to Jeff Lancaster, who was visiting from Auckland.
While he and his family had been having a good time in the “wonderful” city, and at the lakefront playground, he said it was difficult to ignore the stench.
“The smell is quite rancid.”
Bay of Plenty Regional Council Rotorua catchments manager Helen Creagh said lake weed was detached and washed ashore by stormy conditions.
The regional council, along with Rotorua Lakes Council and Te Arawa Lakes Trust, aimed to remove the weed early this week.
“Lake weed wash-ups like this one at the lakefront are a public amenity issue.”
Creagh said lake weed wash-ups would continue as investment in lake weed control was insufficient to remove the weed beds from the district’s lakes.
“More investment in this could significantly improve the issue and we hope that a business case being developed will increase investment – thereby improving public and private amenity, and protecting and improving aquatic biodiversity and cultural values.”
Te Arawa Lakes Trust CEO Daryn Bean
Land Information New Zealand is responsible for the management of lake weed beds and Te Arawa Lakes Trust carried out the work on its behalf.
Te Arawa Lakes Trust chief executive Dr Daryn Bean said that through its initiatives and recent aquatic weed management programme, the trust strove to ensure a future where rotomoana and taonga species thrived. “Including the echoing footsteps of our kō ura or freshwater crayfish as a symbol of water quality success.”
Bean said the work was a collaborative effort involving local authorities, environmental agencies and “more importantly, our community”.
“We address lake weed, like hornwort, through removal programmes aimed at reducing nitrogen levels and improving water quality. Our preventative measures include mātauranga ā-hapū to inform regular weed harvesting to mitigate environmental issues such as odour and ecological disruption.”
He said the recent surge of lake weed underscored the importance of the trust’s efforts and said it was diligent with the mindset there was an “over-arching and allencompassing approach to revitalising and maintaining our pristine wai or waterways”.
Rotorua Lakes Council group manager infrastructure and environment Stavros Michael said it had not received any complaints of lake weed in the past month.
“The weather forecast for next week is likely to see the wind change to a southerly which will also help with the cleanup effort.”
— LDR is local body journalism cofunded by RNZ and NZ On Air.
We address lake weed, like hornwort,
through removal programmes aimed at reducing nitrogen
levels and improving water
quality.