From swamps to sponges: redefining Waikato's wetlands

Originally published February 13, 2018.

Gina Williams of NZ Farmer discusses a vital aspect of the water quality issue - sustaining our nation's wetlands. 

OPINION:  For 21 years, World Wetlands Day has been celebrated on February 2. It was born out of the 1971 adoption of the Convention on Wetlands, or the Ramsar Convention, which is a global treaty for the conservation and sustainable use of wetlands.

For a long time our wetlands have been forgotten about, ploughed up, hoofed up, dredged up and in some cases actively drained out. New Zealand has suffered one of the largest wetland losses anywhere in the world and they are now some of our rarest and most at-risk ecosystems.

Once stretching across 2.2 million hectares, 90 per cent have been drained and today, only occupy about 2 per cent of our land area.

Of the 10 per cent of wetlands remaining, 40 per cent are on private lands, with a large proportion being farmland. Waikato has lost the largest area of wetlands, at 328,290ha or a 92.1 per cent loss.

These losses have been mainly due to farming, through wetland drainage and grazing. Wetlands, or the 'kidneys of the landscape', act like sponges and are effective at filtering groundwater and transforming contaminants lost from the land and nutrients that could harm our rivers; which get into the waterways through leaching and surface run-off.

Microbes living in wetlands absorb and break down these nutrients, which in turn increases the quality of the water.

Conservation Minister Eugenie Sage calls them: "Natural sponges that play a critical role. Not just for their biodiversity, but also in helping create more of a resilient landscape. Particularly in areas where there's increasing drought, they can help habitats survive in dry conditions and store and slow water runoff after a rainfall.

"Because they were called swamps and with the push to drain them and create pasture, people have seen them as 'bad places'. I think, increasingly though, New Zealanders recognise what havens they are for a lot of our native plants and wildlife. They're really significant in creating a landscape that has a mosaic pattern, instead of a monoculture of grass."

New Zealand has six wetlands of international importance among nearly 2300 worldwide and the Department of Conservation is investigating the potential of more.

These are typically partnerships between farmers, the community, The Department of Conservation and councils to protect and restore the health of remaining wetlands.

There's no doubt that farming is a daily juggling act of priorities and responsibilities and making the decision to retire land, re-fence and put plants in the ground isn't easy.

On our dairy farm in Hora Hora, just south of Cambridge we have been fortunate to receive funding for wetland regeneration through The Waikato River Authority.

Over the last three years we have restored over seven hectares of marginal land and switched our focus from 'beefies to bees'.

This funding has been significant in accessing ecological advice and putting plants in the ground. Applications are open annually and can help us get our wetlands in the Waikato back to what they do best.