Thursday, February 22, 2024

Waikato duo’s two-year journey to build a wetland

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South Waikato get advice from Fonterra and help from NZ Landcare Trust’s Nathan Burkepile.
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A South Waikato farming couple have completed a two-year project create an in-ditch wetland on their property.

The work on Jess and Ev Mardell’s farm near the Arapuni Dam harmonises water quality, biodiversity and aesthetic values without disruption to farming activities. 

Their journey began while assessing their Farm Environmental Plan (FEP) when they encountered a boggy area at the bottom of their drainage system (visible from the road as travellers pass by the Arapuni Dam). 

Seeking solutions, their Fonterra Sustainable Dairy Adviser (SDA) recommended contracting NZ Landcare Trust’s Nathan Burkepile for assistance. 

Burkepile said the couple’s story is important because it highlights the development of a wetland within an active farming system with zero external funding.

The Mardells initially sought support from a local funding body, but were unsuccessful. 

However, this unsuccessful application turned into a significant blessing. It allowed them to retain independence and fostered a substantial learning curve. 

After in-depth research and introspection, along with guidance from Burkepile, they opted to cultivate their plants and undertake the project independently. 

During the early stages of the project, external advice suggested watercourse diversion for the wetland. This was completely unnecessary.

Burkepile’s intervention and the couple’s steadfast enthusiasm for the project helped them gracefully bypass this obstacle.

“The initial stages were fraught with uncertainty for the couple, which is typical when you are dealing with numerous unknowns,” Burkepile said. 

“When I developed a wetland creation plan with a native plant list and guided them on plant selection for both wet and drier areas. This empowered them.” 

Jess contacted a local native plant nursery, which provided advice and seeds for her to start growing her own plants. This local knowledge was invaluable.

Digger work started on February 14, 2021, and the first of the plants arrived in May.

The creation of the wetland involved widening the drain to create shallow water shelves on both sides of the drain. 

The lower section of the wetland had a boggy area that was excavated to create a small wetland basin with a new drain dug slightly higher than the basin.

The original drainage channel was cleaned but was left to act as a wetland bypass during major storms.

“Incorporating wetlands in our drainage systems not only will improve water quality but create biodiversity hotspots in an altered landscape while still retaining production values of the land,” Burkepile said.

The 0.2-hectare wetland required 2000 plants, spaced at 75cm intervals for carex plantsand 1.5m for larger trees. 

To address the challenge of plant procurement and minimise costs, Jess committed to growing all the requisite plants.

Harnessing local plant knowledge from retiring local nursery-women, she garnered essential knowledge for wetland species cultivation, culminating in a successful and cost-effective approach.

The primary objective was to integrate a fully functional wetland into the farm system, recognising the need to fence off the boggy paddock bottom to prevent livestock-induced damage. What began as a mitigation strategy has now evolved into a valuable farm asset contributing to the farm’s biodiversity and local ecosystem enhancement. 

As Jess and Ev continue this transformative path, future challenges may surface, prompting ongoing adaptation and learning. Their newly acquired knowledge has already spurred further planting initiatives across their farm. 

The project has been so successful there are now native endemic leeches, Richardsonianus mauianus (Piriawaawa), in the wetland, which they started noticing in November last year.  

In Focus Podcast: Full Show | Friday 19 January

Bryan talks with University of Otago researcher Marnie Prickett about her new research into NZ’s management of drinking water.

She’s found that even after the campylobacter outbreak in Havelock North, we’ve still got some work to do. Then, Federated Farmers Manawatū meat and wool chair Heather Gee-Taylor highlights why Feds is a great place for young farmers.

And senior reporter Neal Wallace gives an update on the supply chain woes hindering our path to market and what 2024 will bring for sheep farmers.

Listen to “In Focus Full Show | Friday 19 January” on Spreaker.

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