Farm dam enhancement significantly improves water quality

Abstract

Artificial water bodies in agricultural landscapes (hereafter ‘farm dams’) are established primarily to support livestock and crop production but also provide habitats for a wide range of native species. Managing water quality in farm dams is essential to animal production and biodiversity. Farm dam enhancement, which includes restricting direct access of stock to dams, can improve water quality in farm dams, by reducing soil erosion and direct faecal contamination, as well as reducing the trampling, grazing, and browsing of vegetation in the immediate catchment. We tested farm dam enhancement as a tool to improve and maintain water quality in 109 farm dams across 34 farms over three years in the sheep-wheat belt of southeast Australia. Using Bayesian Linear Mixed Models, we found that farm dam enhancement significantly reduced levels of phosphorus, nitrogen, turbidity, thermotolerant coliforms, Escherichia coli, and pH. Furthermore, our study revealed links between dam enhancement, increases in vegetation cover, and improved water quality. Our results show that restoration efforts in the surrounds of dams can have positive results on water quality. They highlight the importance of restoration in agricultural landscapes to both agricultural production and biodiversity.