Investigation of the drivers for water quality decline and risks thereof to agricultural activities in the Breede River catchment

Abstract

Agriculture in the Breede River catchment contributes significantly to international exports and the economy of the Western Cape Province. The success of the agricultural sector in the Breede River catchment is an important driver for the expansion of urban and peri-urban areas. However, the expansion of the urban peri-urban footprint and intensified agricultural activities, such as water abstraction for irrigation and the return flows entering rivers, are linked to a decline in water quality in the catchment. Previous studies have shown that water quality in the Breede River catchment has been declining with some potential drivers identified as the rapid urbanisation, limited financial resources and technical capabilities available for the maintenance and upgrade of the capacity waste water treatment works. Although the risks posed to the agricultural industry in the Breede River catchment have been acknowledged, the nature and extent thereof were unclear. The research study was aimed at investigating the key drivers and risks associated with the decline in water quality to the agricultural sector in the Breede River catchment. Subsequently, three Research Objectives were set: (1) to re-evaluate the water quality in the Breede River catchment; (2) to identify the key drivers of the decline in water quality of the agricultural sector in the Breede River catchment; and (3) to identify and evaluate the risks posed by the declining water quality in the Breede River catchment to agricultural activities. In order to meet these objectives, a review of the literature pertaining to water quality and the impact thereof on agriculture, in line with the research title, problem and objectives was conducted. Additionally, an empirical investigation utilising a mixed methods research approach was followed whereby qualitative and quantitative data was collected. The long-term water quality of the Breede River was evaluated through time series, Piper and Gibbs diagram as well as the calculation of the Water Quality Index and comparison of the water quality with national standards in order to evaluate the suitability of the surface water for agricultural activities in the Breede River catchment. In addition a total of 28 participated (farmers and environmental experts) in face to face or online interviews and the completion of questionnaires with both open and close-ended questions. Both the qualitative and quantitative data from the questionnaires were captured for analysis and a thematic analysis, using accepted data coding methods, was conducted. The findings of the study in relation to the objectives were, firstly, that there is cause for concern regarding the water quality in the Middle Breede River section and the potential impact thereof on agriculture. The concern is related to salinity levels generally associated with the underlying geology and irrigation practices as well as the microbiological and nutrient levels, which points to contamination from domestic effluent from inefficient waste water treatment and un-serviced informal settlements. Farmers indicated the most dominant drivers of decline in water quality as:

domestic effluent > population growth > agricultural growth > co-operative governance > geology/ soil, whereas the Experts listing the dominant drivers as: domestic effluent > population growth > geology/ soil > co-operative governance/ industrial developments/ growth in agricultural activities > climatic conditions. The risks posed by the declining water quality in the Breede River catchment to agricultural activities were identified by Farmers as: risk to agricultural activities/ risk to economic growth of the area > risk of impact on socio-economic development > risk to quality of the crops/ products > risk of financial impact on farming operations/ risk to sustainability of agriculture > risk to environmental sustainability. Experts on the other hand listed the dominant risks of the water quality as: risk of impact on socio-economic development > risk to sustainability of agriculture > risk to economic growth of the area/ risk to environmental sustainability > risk of financial impact on farming operations > risk to agricultural activities.