Learn about the wet areas on your land, why they are unique, the benefits of restoring them and some tips along the way.
*Note: This resource is for restoring natural wetlands only. It is not focused on the creation of constructed wetlands.
A wetland is an area of land that is covered by water for at least some of the year. There are various types of wetlands found across Aotearoa New Zealand, such as swamps, seeps, bogs and peatlands. Water is the defining factor of these wetland habitats, as well as the specific plants and animals found there.
Wetlands play an important role in the health of the environment, but only 10% of Aotearoa’s original wetlands remain. Their ecological and cultural significance were overlooked in the past. As a result, the majority were drained for farmland or urban development.
Restoring even small wet areas on your land has a lot of benefits. Learn about these benefits and how to ensure your wetland restoration is a success.
Consider the time and budget required for each of these stages when creating your restoration plan.
Refer to SBN's resource on waterways for a more detailed look at these stages or read on for additional information specific to wetland restoration.
Before starting any work, get to know your wetland. Monitor the source and levels of water and how this changes throughout the seasons. Is the water standing or flowing? Permanent or temporary? What is the water level like compared to the past?
Identify the focus of your project. Are you restoring your wetlands to improve water quality? Do you want to create habitat and provide food sources for wildlife? This can help you decide the size of your project and the types of native plants to include.
If your wetland is accessible to stock, this is a vital step in the restoration process. In some cases, fencing off the area and managing pest plants is all that it takes to help your wetland regenerate.
Fencing the area will stop stock eating native plants, keep animal waste out of the water and reduce erosion and trampling. Check out SBN's tips to fencing your waterway, along with rules and regulations to consider.
Contact your regional council to see if there is funding available to support fencing or planting.
This wetland restoration plan by the Waikato Regional Council is a good template to check out before commencing your project.
A farmers’ guide to restoring natural wetlands by DairyNZ has some great information on why and how to restore the wet areas on your dairy farm.
Planting additional native plants and trees can help maximize the benefits you receive from your wetland. Here are some tips to consider.
Wetlands are divided into different zones depending on how much water is present. Make sure to figure out where these zones lie in your wetland. Plant species have different water tolerance levels and are adapted to living in these different zones.
The following diagram by Dairy NZ highlights the typical zones in a wetland and plants that are commonly found in each zone.
The above list is a guideline only. It is important to seek guidance on the types of plants that are suited to your area’s climate and soils, and to eco-source Ecosourcing refers to the practice where nurseries source seeds of native plants from local areas, grow (propagate) them, so that they can be planted back within the same geographic area. these plants from local nurseries well in advance. Regional councils and nurseries can provide great information on the best plants for your area.
The following guides will help you decide what and where to plant.
Although water is not usually a limiting factor in wetlands, it is still important to take the seasonal changes to your water levels into account when planning when to plant. Consider these handy tips:
A good tip is to plant your coloniser species Coloniser species are those able to grow first at a site. They are able to cope with the drier, hotter conditions in open areas. first, such as harakeke/flax, mānuka and tī kouka/cabbage trees. These plants are fast growing. They will provide a nurse crop to shelter other species that either establish naturally or can be planted later.
Soils within wetlands are predominantly saturated and are typically anaerobic (lacking oxygen). Many of the plant species that reside in these wetland habitats have specialized adaptations for getting enough oxygen. Check out this video by Manaaki Whenua - Landcare Research where plant ecologist Dr Bev Clarkson explains some of these unique adaptations!
Having an ongoing maintenance plan will give your new plantings the best chance of survival. SBN's resource on restoring your waterways provides guidance on what to consider in your maintenance plan. Here are additional tips when it comes to wetlands:
Herbicides: Try to avoid using chemicals in wetland areas. They can spread rapidly and can be harmful to some native plants and animals. This is not always possible, as some weed species such as Willows will be very hard to control without careful herbicide application. Refer to your regional council or Weedbusters for more information.
Algal blooms: The best way to avoid your wetland becoming clogged with algae and water weeds is prevention. Fencing your wetlands and controlling fertilizers from the surrounding area will reduce the amount of nutrients entering the water. Planting along the wetland will also help to filter this run-off and provide shade. In some cases, putting barley straw bales in the wetland has been proven to inhibit algal growth.
The team from Habitat Restorations Aotearoa working at Te Nohoaka o Tukiauau/Sinclair Wetlands have adopted a technique that helps pūrei/Carex secta seedlings become established without using herbicide. They found that a tri-annual herbicide application wasn’t effective at controlling the Glyceria weed that was smothering native plantings.
They trialled weaving kete/baskets from harakeke/flax, filling them with potting mix and then planting the pūrei seedlings inside. These were wedged in small gaps in the vegetation and provided the height and substrate required to grow above the Glyceria weed. The extra height also kept the small seedlings from being flooded out by fluctuating water levels.
Utilising harakeke as a cultural resource ensures traditions and reo is kept alive and skills are passed on."
Glen Riley from Habitat Restorations Aotearoa
Due to the nature of the woven kete, pūrei roots are able to make their way into the sediment below.
Glyceria is shade intolerant. Once the pūrei have grown large enough, they shade-out the Glyceria naturally, reducing the need for ongoing maintenance. Unlike a plastic pot, the kete will eventually decompose as the pūrei establishes within the sediment.
