Time spent in the field this irrigation season has alerted the Netafim Field Team of the extremely poor and worsening quality of available irrigation water in certain areas. According to Dexter Neethling, product manager at Netafim South Africa, water quality has noticeably deteriorated this summer. This statement is based on visual assessments of filters during filter maintenance in-season. “For the first time ever, we have found various organisms growing inside a working filter, where there is no light and high pressure,” he says.
Many of the filters were assessed in the Western Cape but the trend of declining water quality is not limited to this province.
With regards to worsening water quality, there are two phenomena at work. Firstly, there is a definite trend that water quality is deteriorating year by year. This can, of course, be attributed to many factors. Willem Smit, national sales Manager at Netafim South Africa, reports that discussions concerning the long-term decline in water quality attribute it to a long list of negative factors, such as poor municipal management, poor farming practices and climate-related matters.
REPORTED CAUSES OF DECLINING WATER QUALITY INCLUDE:
• Poorly functioning municipal sewage systems that lead to sewage ending up in rivers and dams. • Informal settlements next to riverbanks that lead to pollution of rivers, dams and groundwater. • Increased growth of invasive plant species on water surfaces, killing the natural life in the water. • Poor-quality borehole water that is used for agricultural irrigation due to increased agricultural expansion and drought conditions. This has a negative impact on natural water resources. • Over-irrigation and the negative effect of drainage water and leaching. • Climate change, which leads to extreme weather events. Extremely high rainfall, for example, fills dams with a high concentration of organic material. • Mining and industrial effluent water contaminating natural water resources.
