Estuary clean-up group says working with farmers vital

Algae at Te Waihī estuary in 2018.
Algae at Te Waihī estuary in 2018. Photo credit: Supplied

By Sally Murphy of RNZ

A group leading the charge to clean up a Bay of Plenty estuary says working with farmers is vital to achieve its goals.

Wai Kōkopu, a group made up of tangata whenua, landowners and environmental groups with funding from the Ministry for Primary Industries (MPI), is working to replenish Te Waihī estuary which is known as one of the most polluted in the country.

The catchment comprises 34,000 hectares and runs from the mountains just below the Rotorua Lakes to the Bay of Plenty coast.

Group project manager Alison Dewes said there are about 220 orchards and 69 dairy farms upstream from the estuary.

"It's a real mix of land uses coming into the receiving water body at the base which is the little Waihī Estuary.

"The estuary is fairly degraded, it's had a permanent shellfish gathering ban for about a decade due to a range of cumulative factors such as high nutrient loads sediments and pathogens being deposited there," she said.

Dewes said the degradation is from years of pollution and river abstraction from the three rivers that feed the estuary.

Wai Kōkopu received $1.45 million from MPI earlier this year to help revitalise the health of the estuary.

The group held a meeting with farm advisors this week to start the conversation about what needs to be done.

Dewes said it was a great start with about 60 advisors attending.

"That's a lot for a small catchment, everyone's on board with improving things from a farmer's point of view, we've had no resistance they're very keen to get on board."

She said many are already making changes to their properties to reduce runoff and leaching.

"We have some significant cuts to be made in the next generation - we need to reduce nitrogen losses by about 66 percent from current loads to achieve a moderately healthy estuary.

"Phosphorus needs to be reduced by around 30 percent, E coli loads to the estuary need to be reduced by over 50 percent - these are pretty significant cuts," Dewes said.

She said a big focus of the project is educating farmers about what they can do to achieve better environmental outcomes.

"Because there hasn't been any high degree of regulation in coastal Bay of Plenty the farmers are in a situation where they haven't been exposed to a lot of things that need to be done like understanding their nutrient budgets or how to alter their farm systems to tread lighter while still being profitable."

There are about 6000km of stream and river edges that might need protecting with either stock exclusion or planting.

Wai Kōkopu is creating a long-term plan for restoring the estuary over the next 20 years.

Dewes said the first meeting with farmers in the catchment will take place next month.

"It's about having a discussion and showing them the data we've already collected to make sure we are all in the same waka going towards one common goal."