Written by Melanie Dixon – Principal Ecologist at Thomas Consultants

Last September the Government bought in new strong rules to protect wetlands – with good reason – recent work by the National Wetland Trust and others shows that we’re continuing to lose wetlands in New Zealand at an alarming rate.

Roll on one year the Ministry for the Environment is already consulting on changes to the legislation, including changes to the “natural” wetland definition. With no minimum size and no requirement for the wetland to support native plants the definition has picked up a lot of degraded wetlands. That was never the intent of the changes. As stated in the Ministry for the Environment’s regulatory impact statement “As it is currently defined, a natural wetland is being interpreted to include areas that, although technically wetlands, were not intended to be captured by the definition of a ‘natural wetland’ and subject to the regulations – such as seeps in pasture. This has led to more areas than intended being subject to the regulations.”

In Auckland we’ve found that the current definition has picked up lots of areas dominated by Glyceria maxima a grass with the wetland indicator status of “obligate wetland plant” (Clarkson et al 2021). Glyceria is an invasive species that forms dense mats and traps sediment – it can transform what were very likely small streams when the land was forested into “induced” wetlands (see photo). Under the current rules not only is it prohibited to destroy such a wetland, but activities also such as wastewater disposal and stormwater disposal within 100m of the wetland have to be assessed by an ecologist. In some parts of Auckland it seems you can’t throw a stick without hitting a wetland and everyone needs a wetland assessment for their project!

The proposed new exclusion to the definition, below, should address this:

(c) any area of pasture that has more than 50 percent ground cover comprising exotic pasture species or exotic species associated with pasture.

This new definition is an improvement. However, it still gives ecologists plenty to argue about. e.g. what exactly is an “exotic pasture species”, will a list be made available? And in an effort to “throw out” some of the smaller more degraded wetlands from the “natural wetland” definition will we accidentally throw out valuable swamps worthy of protection? For example, a lot of the internationally recognised (RAMSAR) Whangamarino Swamp in the Waikato is crack willow growing over Glyceria and it’s the strong hold for our critically endangered bird the Matuku or Australasian Bittern.

It’s critical that we get this right – destroying or degrading wetlands can have grave consequences, such as loss of species, increased flooding, decline in water quality, and release of carbon from wetland soils. Common ideas of what a wetland should look like may not include all types of wetlands. On the other hand the current rules are forcing people to go through hoops for their development when there is a wetland within 100m that sometimes is not even on their property and has very little value.

If you would like to read more about the proposed changes to the definition, it’s on the Ministry’s website HERE

Submissions close on 27 October 2021, You can submit HERE

Thomas Consultants will be watching this space closely and how these changes develop which will affect future developments across New Zealand.