Restoring a wetland - next steps

 

(6) Provide ‘extras’ for wildlife

Extras for birds

As well as providing the basics for birds (water and shelter), you can provide a number of ‘extras’ that will make your wetland a highly desirable home:

  • Provide logs and trees in the water as well as gentle, sloping banks for perching sites and shelter.
  • Create bays and screens of plants for birds to hide behind.
  • During the breeding season (July to December for most species), either stop or significantly reduce grazing and other activities – birds are particularly sensitive to disturbance at this time.
  • Carry out regular predator (eg. stoat and feral cat) control throughout the year. The best method is to carry out intensive control prior to and during the bird breeding season, with maintenance control throughout the rest of the year.
  • If your wetland is near a block of native bush or another wetland, consider linking them with a ‘‘green corridor’’ of native plants.

Contact the Northland Regional Council’s Land Management Team, or your local Department of Conservation office for more advice.

Extras for fish

If your wetland is connected to a stream (or streams) at least 10 cm deep, it should be accessible to most native freshwater fish. A number of native fish species spawn in estuarine areas and the young migrate upstream. Long stretches of fast-flowing or polluted water and overhanging culverts can act as impassable barriers and stop fish reaching your wetland.

Native fish also need streams with clear water, shading and cover. Muddy water limits their vision and reduces their food supply of aquatic insects.

Help fish find your wetland using the tips below:

  • Plant overhanging species like harakeke (flax) and sedges for shelter and to keep the water cool.
  • A hay bale placed at the head of a ditch entering your wetland will act as a simple silt trap.
  • When clearing drains, leave one side or parts of it untouched until plants have grown back. Plant tall trees on the north side for shade.
  • If using culverts in streams, set them low in the stream bed.
  • Rough up the smooth bottom of culverts with cement or rocks to slow water flow.

Fish pass.

(7) Start planting

Prepare a planting plan

Plant appropriate species in your wetland. Plants such as raupo do not grow in peat bogs, so seek advice to ascertain what type of wetland you have. Common plants such as manuka, flax or cabbage tree are available cheaply in nurseries and may be the best option for the early stages of your replanting programme.

Make sure your wetland is thoroughly stock-proof before you plant.

When you’re ready to plant your wetland, divide it into three plant zones:

  • Margins and banks with drier soils.
  • Wet soils, with regular temporary flooding.
  • Shallow water/water margin.

Start by spending some time to observe what is already present on the site. Identify any desirable plants you already have in each zone, and list the plants you can use in each, taking into account wind and drainage. The guide on the following page includes a small sample of potential species. Not all will be suitable for your area or situation – coastal and upland areas, in particular, have their own species associations.

Coastal saltmarshes usually grade into swamps, so you may need to use both coastal and high fertility freshwater species.

Discuss your list with local experts such as native plant nurseries, Northland Regional Council Land Management Team and the contacts at the back of this guide.

Planting on wetland edge. Planting on wetland edge.

Eco-sourcing

Eco-sourcing means planting appropriate native plants which come from close to your wetland. Generally, sourcing plants from within your ecological district is acceptable. Local plants are usually adapted to local conditions and grow the best. Also, many species are genetically variable from area to area even though they may look similar. Many nurseries sell local plants, so always ask first.

You may also be able to grow some of the plants you need from seeds or cuttings taken from neighbouring wetlands. Make sure you get the landowner’s permission first. Keep use of cuttings to a minimum and take them from a large number of parent plants, to ensure a good genetic mix. Where appropriate, ensure that you have both male and female plants. Specialist nurseries often have a good range of wetland species from your local area.

Timing

In wet areas, around the water’s edge and in shallow water, plant in summer when water levels are low, the water is warm and birds have finished breeding.

Otherwise, plant hardy, frost-tolerant species in autumn and winter. Plants that need shelter or shade can be planted one to two years later, once cover has developed.

Site preparation

Clear a one-metre circle around each planting spot with a spade or herbicide to prevent competition from grass and weeds. This will make sure your plants get enough light and nutrients.

Planting

Remember, native plants don’t tolerate grazing by stock - protect your investment by keeping stock out.

When planting:

  • Choose sites suitable to each plant’s growing requirements, leaving space for them to grow. Ferns, rushes and small sedges can be planted three per square metre. Larger plants need more room. Planting at least one plant per square metre saves work clearing or replanting later.
  • Dig a hole twice the size of the plant container, leaving some soft soil at the bottom. Set the plant in the hole and gradually fill in the soil, compacting it to remove air gaps.
  • If you’re planting on dry sites around the edge of your wetland, form a hollow around the plant’s base to trap rainfall. Plant dry sites in spring or autumn.
  • Give the plants and surrounding soil a good watering. Water young plants over dry spells.
  • In very wet soil plant nursery-grown plants on a small mound about 30 cm high, to give their roots time to get used to the saturated soil. Plant wettest sites during summer.

Stakes next to the plants, at this stage, will make them easier to find later. Tall, thin bamboo stakes highlighted with spray paint are ideal.

(8) Looking after your plants

Weeds can overwhelm your plants in the first one to three years and smothering by tall grass is the most common cause of failure.

It’s important to maintain your plants by clearing the weeds around them. You can weed by hand or with a grubber or with careful use of a suitable herbicide - and save further weeding by using mulch or mats (eg. non-rubberised carpet underlay) that eventually decompose.

Pests such as rabbits and possums should also be controlled, particularly early on. Pukeko and rabbits can be deterred by painting a mix of egg powder and acrylic paint onto young plants.

Once the plants have grown tall enough, they will begin to shade out grasses and aquatic weeds and will no longer need weed control.  After about three years your plantings should take care of themselves. Overhanging trees and plants will provide shade, reduce water temperature and provide habitat for fish and invertebrate species. Long, dense grass is excellent for trapping any run-off from the surrounding catchment.

Herbicides

There are some herbicides registered for use on and under water. Seek advice for use. Glyphosate herbicides reduce the need for manual weeding if used carefully. We don’t recommend long-lasting residual herbicides, as they remain toxic to plants three to four months after application.

The best time to spray is late summer when water levels are low and nesting and flowering has taken place.

You can get more information on suitable herbicides and suggested application rates from Biosecurity Officers at the Northland Regional Council. Always follow the herbicide manufacturer's instructions.

You may need to get consent from the Northland Regional Council, depending on what herbicide you use. Check first.

More planting tips

  • The best time to plant in wet areas is in summer when the water levels are at their lowest.
  • To ensure your plants have the best possible chance of survival, use larger potted plants. These are also less likely to be uprooted by pukeko.
  • When planting the dry edges of wetlands, use a mulch at least 10 cm deep. This can be untreated wood chips, compost, cardboard, old non-rubberised carpet underlay or rotted hay. It will help to reduce evaporation, keep weeds down and add nutrients. Alternatively, leave a low grass cover around the plants for the first summer (until March) to help conserve water.
  • Use fast-growing species such as manuka as nurse plants to provide shade for seedlings underneath.
  • Plant natives such as coprosmas which bring the birds. Birds assist natural regeneration by spreading seed.

Te Werahi wetland, near Cape Reinga. Te Werahi wetland, near Cape Reinga.

(9) Monitor your progress

Make sure you maintain an ongoing programme of weed and pest control. Keep a photographic record and a diary of progress. It will help you to learn what works and what doesn’t and make changes as necessary. It will also be a record to show you how much you have achieved and what additional plants and animals arrived naturally as your wetland recovered.

(10) Protect your investment

You can protect your investment of time and energy by placing a covenant on the site. This means you or subsequent owners retain ownership and control, but the wetland is protected forever. There are several different kinds of covenant.

Contact the QEII National Trust for information and advice on covenants.

Northland Regional Council Wetland Database

If you would like your wetland to be listed on Northland Regional Council’s Wetland Database, please contact a Land Management Officer on 0800 002 004.

(11) Wetland rules

Illegal rubbish dump in wetland. Dumping rubbish close to wetlands is not allowed.

Wetlands are covered by Northland Regional Council’s Regional Water and Soil Plan for Northland. The plan has nine criteria that define Significant Indigenous Wetlands. A wetland only has to meet one of the criteria to qualify. This means that most wetlands dominated by native plants are classed as significant. The reason for the tight criteria is that more than 95% of Northland’s wetlands have been cleared and drained and so most that remain are considered important.

Rules in the Water and Soil Plan mean that most human activities which are undertaken in Significant Indigenous Wetlands are noncomplying and require resource consents. Even activities such as drainage or maintenance of drains on neighbouring properties require consents if they could cause any change to the seasonal or annual range in water level of an indigenous wetland to such an extent that it may adversely affect the wetland’s natural ecosystem.

Activities covered in the plan that could affect wetlands include:

  • Land disturbance including excavation, drilling, reclamation, vegetation clearance and drainage.
  • Earthworks or vegetation clearance within the riparian management zone (a strip of land of up to 20 metres width around a wetland).
  • Building of structures including culverts, bridges, causeways crossings, dams, weirs, pipelines, fences and maimais.
  • Discharges including wastewater, domestic sewage or animal effluent and other contaminants within 20 metres of a wetland, river or stream.
  • Burning.
  • Dumping of rubbish.
  • Disposing of dead stock within 50 metres of a wetland or waterway.
  • Coastal grazing – stock must be fenced out of the area below spring tide, including saltmarshes.
  • Planting – the introduction of any plant species listed in the Northland Regional Pest and Marine Pathway Management Plan is prohibited.
  • Herbicide – certain herbicides are registered for use on or under the water. Seek advice from a Northland Regional Council Biosecurity Officer before using herbicides in wetlands.
  • Water take – a certain amount of surface water can be taken for domestic and stock needs provided it has no more than a minor effect on a wetland or natural ecosystem.

Created a wetland?
Register it!

 

If you have created a wetland in a site where one did not previously exist, it's a good idea to register it with Northland Regional Council so you can manage it later. To find out more, contact the council's Land Management Team on 0800 002 004. 

 

 

Check first with the Northland Regional Council and your district council if you are going to undertake any of the above activities in or close to a wetland. If you see any of the above activities occurring in or near a wetland without a consent – please phone the Northland Regional Council’s 24/7 Environmental Hotline 0800 504 639.