A seven-year forestry study aims to determine the most effective measures for reducing erosion and sediment in rivers from harvesting.
Robust real-world studies are the best way to find out what erosion and sediment control measures work best, an MPI manager says. (file pic) Photo: Supplied / Ministry of Conservation
The project is now in its second year at forestry company OneFortyOne's Donald Creek Forest, near Tadmor in the Tasman district.
It has just received $1.37 million from Ministry for Primary Industries through its Sustainable Food and Fibre Futures fund.
MPI's director of investment programmes Steve Penno said the only way to find out what erosion and sediment control measures worked best was through robust, real-world studies.
"This project is exploring the effectiveness of current best practice in sediment control as well as some new innovations. Later in the project, the researchers will construct a large sediment retention pond to see how that measures up compared to traditional methods.
"As well as the benefits of erosion and sediment control, the programme will also compare the costs of different practices."
Penno said the data collected from the project would inform how the forestry industry meets new government freshwater management standards for suspended and deposited sediment.
It would also provide scientific backing for the most effective forestry practices that had the best outcomes for the environment.
OneFortyOne's executive general manager New Zealand Brent Guild said as a long-term business, it made sense to invest in long-term studies like this one.
"The data will help us understand the impacts of our business. It will help us learn what works well and where we might do better."
It was working alongside Cawthron Institute, Envirolink, Manaaki Whenua - Landcare Research as well as the Ministry for Primary Industries.
Two similar plantation catchments had been set up, including a control catchment that was exposed to the same weather, but would not be harvested.
"This is a valuable opportunity to test the performance of traditional and new in-forest sediment management techniques - and we are grateful for MPI's support to help us do this important work, which we'll be able to share widely with the forestry sector."
Guild said it would give a better understanding of which strategies are best value for money.
"For instance, if the results show that sediment traps are an effective treatment, we'll have the confidence to persist with this practice without calling on additional resources.
"However, if we find that the environmental impacts are too disruptive, this would provide the rationale for investing more money in sediment control at source to achieve environmental benefits."
