Turning one of New Zealand’s most polluted water systems around is the tough job Alison Dewes expected it to be, but she remains inspired by farmers’ efforts in the past three years.
Dewes is operations manager and one of the founders of the Wai Kōkopu catchment group in Western Bay of Plenty. The 35,000ha catchment area feeds into the Waihī estuary at Maketu, once a valued source of seafood but now severely degraded from high nutrient loads and pathogens.
The catchment includes 220 orchards and 69 dairy farms stretching back into the steep hill country that lies between the Bay of Plenty and Rotorua Lakes district.
“There is a need in this catchment to reduce nitrogen levels by 70%, phosphate by 30-40% and also deal with high E.coli levels,” Dewes said.
Three years ago, the group secured $7.5 million in funding from the Ministry for Primary Industries, the Freshwater Improvement Fund, and philanthropic grants from TECT and Bay Trust.
While much has been achieved in helping farms make changes, Dewes is under no illusion there is plenty more to be done.
In the three years since, 15 leading farmers have opened up their properties and books to enable a deep dive into their operations and nutrient management. That includes doing land use capability maps, Overseer budgeting and loss calculations, and tracking nutrient changes and losses over four years.
“This has given us the ability to say ‘What can these farmers do while still remaining economically resilient, while lowering their footprint?’”
With only this year remaining in its funding window, the group is hoping further funding will become available while it pushes ahead with its focus on demonstrating how farmers can lead in establishing viable, practical environmental management in catchments.
The Nettleingham dairy farm at Pongakawa has been held as an example of how a challenging, high-discharging dairy unit has transitioned to one of these lower footprint farms, while still remaining viable (see accompanying article).
Having retired 28% of the farm into exotics and native plantings, the property is recording a drop in nitrogen losses of a third against its original operation.
Working with the Nettleinghams, the group found the better country on the farm was generating almost twice the feed its steep 30-degree-plus slopes were generating.
Retiring the steep country on the edge of the Pongakawa River that feeds into the estuary is significantly reducing the river’s nutrient load, and has left the couple to focus on their better-quality milking country for optimal return.
Looking out to carbon reduction needs, the property has also managed to slice its emissions by a third.
“Four or five of our major land users have made moves like this across the last three years with good information and support,” Dewes said.
Other achievements by the group in its three years of operation include having over 50 farm plans completed and retiring and restoring over 200ha of steep vulnerable land to natives and exotics, with a further 50ha being sought for this year.
More than 200,000 trees have been planted, with another 100,000 scheduled for this year. The group has also proven the Timata tree planting method is an economically viable means of getting more natives in the ground and quickly established.
“We are now at the point where we are going to treat the entire catchment as a farm. We are going to model that, looking at the most economic mitigations to get the sort of nutrient reductions we need to get.”
With one eye on extended funding to keep the group running, Dewes is excited by the prospects for farmer catchment groups nationally.
As they have expanded in both islands, she said, within a year it is quite likely all New Zealand’s farmer catchment groups – which encompass over 3 million hectares – will come together under a single collective umbrella.
She said this would add horsepower to the groups’ desire to see farmer-led initiatives rather than council regulations setting the agenda for land management.