Waikato River.
Over the summer holidays, the health and wellbeing of the Waikato River have been a hot topic. Writing this as we are in the middle of the National Waka Ama championships, with close to 5000 children and adults on the water, the question feels immediate and unavoidable: how do we balance the needs of recreational users with the long-term health of the river that sustains us all?
Lake Karapiro Domain general manager Liz Stolwyk scoops up golden clams from the lakebed during the annual lowering at Karāpiro. Photo: Mary Anne Gill
The Waikato River is far more than a body of water. It is a living taonga, central to identity, culture, recreation and regional wellbeing. On any warm summer’s day, it carries rowing crews, swimmers, anglers, jet skis and families enjoying the riverbanks. Major events bring people that provide a huge economic benefit to our region as well as fostering a deep connection with the river. That connection matters – because people are more likely to protect what they value.
But the river is under increasing pressure.
This summer, the fast-growing hornwort weed has been particularly exasperating. On New Year’s Day, I watched a continuous trail of weed. For recreational users, hornwort clogs propellers, fouls paddles, restricts swimming areas and disrupts events. For the river, it is a visible sign of wider ecological imbalance.
Just another event – Liz Stolwyk and Andrew Reymer are behind the wheels at Karāpiro. Photo: Mary Anne Gill.
Each year an annual hornwort spray programme is completed by mid-December. While necessary, it captures only a small portion of the problem. The programme costs over $100,000 annually and is not without controversy, particularly due to the use of the herbicide ‘diquat’. Community concerns about effectiveness and environmental impact deserve to be heard and addressed openly.
Complicating matters further is the spread of the invasive gold clam, which has now taken hold in parts of the Waikato River. These clams are extremely efficient water filterers. While that might sound positive, clearer water allows more light to penetrate the river, creating ideal growing conditions for hornwort. Many recreational users are now observing what science is confirming: the gold clam invasion is likely accelerating weed growth and changing the river system in ways we are only beginning to understand.
Hornwort and gold clams are symptoms of a stressed system rather than isolated problems. Nutrient runoff, sediment, invasive species and warming conditions all interact, creating cumulative impacts that cannot be solved with a single tool or programme.
One of the community tours gathers on the bridge at Karāpiro Dam on the Waikato River. Photo: Mary Anne Gill
Balance does not mean choosing recreation over river health, or vice versa. A healthy river is the foundation for recreation. Without clean water and resilient ecosystems, there is no future for summer swimming or the simple enjoyment of being on the water.
So, what does balance look like? It starts with shared responsibility. Councils, Central Government, Iwi, Farmers, Industry, Event organisers and everyday river users all have a role. It means investing in long-term, catchment-wide solutions, supporting science-based management, and respecting our obligation to care for the river for future generations.
Seeing thousands of paddlers moving together on the Waikato River is powerful. If we can bring that same collective spirit to caring for the river, we can protect both its health and our ability to enjoy it – now and into the future.
- Liz Stolwyk is site manager at Lake Karāpiro Domain.
Waikato River
