The strip of land beside a waterway is a called the riparian zone and it is a crucial buffer between land and water.
Riparian buffer zones can consist of ungrazed grass, commercial trees, stock shelter tree lines, native plants, carefully grazed grass or a combination of these, but ideally they are home to many species of plants that existed prior to land development. Effective riparian zones include plants that can deal with floods and seasonal wet and dry periods, and will improve the health of your waterways.
Why do we need riparian zones?
Land development for farming, urban areas, industry and flood control has removed much of the original vegetation along our region's streams. This has resulted in greatly increased amounts of sediment, nutrients and bacteria entering waterways via runoff. Given that Southland has over 17,000 km of waterways, creating effective riparian zones can significantly reduce impacts on water quality and biodiversity.
In terms of farming, the key reason to create a riparian zone is to exclude stock from the waterway, and to have a buffer between the water and land to reduce soil, bacteria and nutrient losses.
Some on-farm benefits of riparian zones include:
- Reduced losses of sediment and nutrients from the land.
- Reduced stock losses, provision of shelter and helping with stock control.
- Reduced drainage maintenance from excessive weeds and silt.
- Minimised flood damage to farmland and infrastructure.
- Increased land and farm value.
Benefits for the wider community include:
- Stabilised banks and reduced erosion.
- Improved water quality and increased biodiversity.
- Improved recreational and cultural values
Create effective riparian zones
Waterways vary throughout the region and within a single property. However, you can create a successful and valuable riparian zone by following some key steps.
Maintaining riparian zones
Once a riparian zone has been established, it needs regular maintenance in order to stay functional and effective. Creating riparian zones is an investment, so to help you protect them we've put together some tips.
Weeds in riparian zones
Weeds are 'experts' at colonising bare ground. They are fast growers that will out compete riparian plantings for light, nutrients and moisture. Good weed control while your plants are establishing will not only help with their survival, but will also promote early growth.
Pest animals in riparian zones
Good pest management is key to the success of your riparian planting project. Riparian zones can be great for attracting wildlife, however, they can also be a smorgasbord of tasty treats and an inviting environment for hares, rabbits and possums.
Download the Pest animals in riparian zones factsheet.
Excluding stock from waterways is the best 'first step' you can take to improve waterways in the Southland region. What kind of fence you use will depend on its purpose, the type of stock being grazed and how much money you can afford to spend on fencing.
Riparian plants for Southland
When choosing plants for a riparian zone, there are a number of factors to consider. It is important to select plants that will do well in your location and can tolerate local conditions. They also need to be the right plant for the job (e.g. for water quality protection or improvement, shelter, bank stabilisation, timber production, aesthetics or biodiversity values).