environment

What’s a swamp worth?

Ahead of World Wetlands Day, Farah Hancock reports on three different wetlands and looks at the value they bring to their surroundings.

One of Auckland’s largest pieces of storm water infrastructure comes complete with a skate ramp, playground and dog-walkers.

Machinery can’t be spotted and people strolling around it wear athletic-wear, not safety vests.

The 40-hectare Waiatarua Reserve is home to a restored wetland which filters water that's run off from surrounding land and roads. The water, filtered through bunds and sediment traps, flows into Ōrākei Basin and then into the Waitematā Harbour.

It’s estimated each year the wetland stops 130 tonnes of sediment and contaminants from entering the basin and harbour.

World Wetlands Day, held February 2, hopes to bring attention to the wetlands under our noses, and those that have disappeared as land is drained for homes and farms.

Around 10 percent of New Zealand was once covered with wetlands. Ninety percent of those wetlands are now gone and some of the species they are home to teeter on extinction.

The National Wetland Trust has set an initial goal of restoring 20 percent of New Zealand’s lost wetlands.

Some wetlands are likely to be restored on council land and there’s hope farmers will voluntarily set aside some of their land to re-establish them. Locations like Waiatarua Reserve set a precedent for the role wetlands can play in an urban environment.

Waiatarua: urban wetland

Vijesh Chandra, a trustee of the National Wetlands Trust and civil engineer, has a focus on dealing with stormwater run-off.

“There’s always been an issue with water quality in Ōrākei Basin, this wetland has been great in terms of keeping all the contaminants back.”

Despite the occasional concern over maintenance, it’s mostly been a success story for the community. The $5.2 million project turned what had been a boggy area into a well-used recreational spot which doubles as a picturesque stormwater treatment facility.

While some might think a civil engineer being a trustee of a conservation group odd, Chandra thinks it shouldn’t be.

“I want to make a difference.”

His work has given him experience dealing with local government infrastructure at a strategic level, which he says can be helpful in drumming up support for partnerships.

The National Wetland Trust has big ambitions but with limited resources ambitions will remain dreams, he says. 

“The money is there. There’s a lot of money. New Zealand is quite rich. Farmers make a lot of money. Fonterra makes a lot of money. There are opportunities to extend the number of wetlands there are in New Zealand.”

The issue is the perceived value of wetlands.

“If people can’t see the value of wetlands it’s not going to happen.”

For wetlands like Waiatarua, the community has seen the value in the area as a recreation space.

“People come here for walks. People come in the weekends to relax, there are lots of kids and families coming here to look at ducks and birds. That’s value. It’s accessible and easy to get to.”

“For most of us growing up, there weren’t many wetlands you could access. They were only the sort of places duck shooters or mad scientists went to.”

Lake Rotopiko

Fifteen minutes’ drive from Hamilton is the National Wetland Discovery Centre. Despite the grand name, it’s very much a work in progress. Initially, it was little more than a paddock with a lake, a few trees and a muddy track. Now a predator fence surrounds the area and it’s teeming with plants and wildlife, and boardwalks have been built.

As well as having local biodiversity value, it’s hoped this will eventually become a tourist destination and will help raise the profile of wetlands so people consider them a place to visit for recreation, like kayaking or bird-watching.

When it’s suggested wetlands aren’t a traditional recreation destination, Wetland Trust ecologist Karen Denyer points out this could be because most have been drained.

“For most of us growing up, there weren’t many wetlands you could access. They were only the sort of places duck shooters or mad scientists went to.”

Installing boardwalks is one way to help people access wetlands, she says. 

“Our little tagline is ‘Getting Kiwis into Wetlands’, mentally as well as physically. We think you have to get them physically into a wetland to go ‘Wow, that’s beautiful’.”

The centre has worked with the local community. A local school helped with a science experiment to find a cheap, effective lure for mice traps. After much experimentation, wine corks soaked in peanut oil came out on top.

Even duck hunters who have previously used the lakes are supportive of the work the trust is doing. There are plans for at least one old mai-mai to be upgraded to be a spot for bird photographers.

Local iwi Ngāti Apakura has also been involved, working with the trust to restore the wetland, ensuring access is maintained for cultural practices such as gathering and colouring flax. Iwi members consult on decisions around pest control and introducing new species.

One species reintroduced to Ropotiki is the giant cane rush, which is found in only a few locations in the Waikato. Inside the slender stems lies a surprise about the size of a piece of cotton thread, says Denyer.

“The skinniest caterpillar in the world, called ‘Fred the thread’, lives inside the stem and chews it from the inside, leaving beautiful intricate patterns.

“It’s an ugly duckling story. It’s a really unattractive caterpillar that lives inside, but he turns into the most beautiful moth.”

Houdinia flexilissima - or Fred the moth. Photo: © Manaaki Whenua – Landcare Research 

'Fred the thread' was the first threatened creature brought to the wetland. Since then, some threatened species - such as the falcon and spotted crake - have self-introduced.

The centre does cover a large area, but Denyer says even restoring a small area of wetland can be used by wildlife. A farmer restoring a paddock to wetland could make a difference.

“As an ecosystem type, there was a lot of small wetlands around. Wetland wildlife kind of evolved to move around site-to-site. Instead of just moving into a forest and living there their entire life, they follow resources around."

The benefits extend beyond wildlife: not only are they a carbon soak, they can help farmers through both wet and dry times.

“Even with small ones [wetlands] you can use them to store excess flood water, you can use them to store excess ground water. If you are storing water in wetlands in the winter time, it will keep the ground water higher for the summer, so you won’t get the droughts.”

“Change is coming. Especially from regulation from regional government level."

The land of milk and honey

Gina Williams’ family has an organic farm in the Waikato which produces milk and honey. So far, they have restored around 10 hectares of marginal land as native wetland.

Williams says her view of organic farming is doing the right thing by animals and the environment.

“With organics though, the regenerative aspect doesn’t always come through. For us, organics plus regenerative equals the kind of future of what agriculture should be. Especially in New Zealand.”

The land which has been restored to wetland involved using a spring between two hills. The family was concerned that heavy beef stock grazing the area could lead to erosion, so chose to extend the fencing around the spring to include a far larger area.

Around 30,000 trees and shrubs have been planted, with plans to eventually plant another 3 hectares of land.

The extra flowers from the wetland planting provide valuable food for bees the family keeps.

“The wetland plants have definitely helped with attracting more bees. That’s good for our pasture too. For us, the wetland does play a big part in the overall health of the farm.”

For farmers considering establishing wetlands, she has some advice.

“We know a lot more about wetlands than we did 20 or 30 years ago when we were all dredging them and making them disappear. We know they are good for the environment.

“Change is coming. Especially from regulation from regional government level. The earlier you can get on to things the better. You can make it work for you.”

World Wetlands Day events can be found on the  National Wetland Trust website.

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