Dairy farming is a water-intensive land use and one which can degrade water quality. Examples of potential impacts include:
- Nutrient enrichment into watercourses from runoff of slurry and fertilizers applied to pastures, or from slurry dam spillages;
- Sedimentation caused by soil erosion or soil disturbance during pasture rotation; and
- Bacterial contamination (e.g. E. coli) caused by cattle directly accessing watercourses and defecating in the water.
These impacts are compounded by high levels of water abstraction leading to reduced dilution capacity of surface waters.
All of these potential impacts require management interventions and mitigation. A watercourse buffer zone is considered an effective option for contributing to the protection of watercourses.
Buffer zones associated with watercourses have been shown to perform a wide range of functions and have, therefore, been adopted as a standard measure to protect watercourses and associated biodiversity. Some of these key functions include:
- Maintaining basic aquatic processes (e.g., water infiltration, shading, sediment trapping);
- Reducing impacts on watercourses from upstream activities and adjoining land uses;
- Providing habitat for aquatic and semi-aquatic species;
- Providing habitat for terrestrial species; and
- A range of ancillary societal benefits (e.g., reduced flood risk, enhanced visual quality, control of noise levels).
The Institute of Natural Resources NPC, in partnership with Confluent Environmental and WWF-SA, was awarded a three-year research project through Milk South Africa’s (MilkSA) Research and Development Programme. The project will contribute to the sustainability of the dairy sector through the development of best practice guidelines for improved wetland and river management through the implementation of buffer zones on dairy farms. The guidelines being developed within this project will provide a framework for guiding the design of appropriate watercourse buffer zones and practical information on buffer zones, and how they should be considered in conjunction with alternative sustainable management practices for improving wetland and river management on dairy farms in South Africa.
The project concludes at the end of February 2023, after which the guidelines will be made available.