Advances in assessing the impact of hillside farm dams on streamflow

Hillside farm dams play an important role in Australian agriculture, providing essential supplies for stock, domestic use and irrigation. Methods to assess the impact of hillside farm dams on streamflow were first developed in Australia around fifteen years ago and have progressed continually since then. This paper presents a number of recent advances and provides a summary of available techniques. Uncertainty in modelling was assessed using a Monte-Carlo framework to test whether recent improvements in techniques lead to a reduction in uncertainty. The annual impact of hillside farm dams in a test catchment was estimated with an uncertainty of ± 24%, which represents a reduction in uncertainty by nearly half when compared with previous methods. It is therefore recommended that the techniques described in this paper be applied in future studies of hillside farm dam impacts in Australia.