Riparian zone planting

Riparian zones are the areas that border streams and rivers, and other bodies of water like ponds and lakes. Planting riparian zones benefits the environment by filtering sediment and nutrients before they enter waterways. The plants also help prevent bank erosion and improve the habitat for native wildlife.

Benefits of riparian planting

The benefits of riparian zone planting include:

  • improved streambank stability
  • shade to decrease water temperatures – this reduces weed and algae growth and provides stable temperatures for aquatic life
  • slowing the rate at which some sediments, nutrients and bacteria enter waterways
  • improved habitat quality for fish, insects, birds and aquatic plants
  • increased biodiversity
  • improved landscape aesthetics.

Research by Scion looked at the benefits of planting trees around waterways.

What are riparian zones?

 Riparian planting can be divided into 3 zones:

Lower bank zone

This is the strip of land prone to flooding. Plants must be able to tolerate waterlogged roots and survive many days underwater.

Plant at 1 to 1.5m spacings.

Middle bank zone

This zone is on higher ground but may partially flood every couple of years. Use plant species that can tolerate having damp feet.

Plant at 2.5 to 3m spacings.

Upper bank zone

May partially flood every couple of years. Plant species that prefer dry conditions. If planting on farms, then leave a grass strip at least 1 metre wide.

Riparian planting guides

Dairy NZ has regional planting guides which have a planting list appropriate to each region. 

Planting waterways – DairyNZ

Your regional council may also have riparian planting guides.

Council maps and websites – Local Government New Zealand

Sometimes you could look at planting fast growing willows to stabilise any highly eroding streambanks. If preferred, they can then be cut back and natives established to gradually replace them.

Case studies on YouTube 

DairyNZ's video on how to make riparian planting a success talks about planting techniques and tools.

Three steps to make riparian planting a success video – DairyNZ

Waikato Regional Council's video shows how dairy farmers, Barry and Julie Burwell, successfully plant their riparian areas.

Riparian planting video – Waikato Regional Council

If there is an active catchment group in your area, consider prioritising your waterways that contribute to the catchment group’s work. See if the catchment group can help with your planting and maintenance.