The estimation of farm dam yield in small agricultural catchments in south eastern Australia

Abstract

This paper presents the development of a method to estimate catchment yield related to the sizing of farm dams in small ungauged catchments in south-eastern Australia. Three measures of catchment yield were determined, namely mean annual flow, mean winter flow and harvestable runoff at given probabilities of failure. The techniques for predicting catchment yield include the use of multiple linear regression and regression trees. The accuracy of the prediction models compared favourably with published results obtained for similar studies. These estimates of catchment yield were applied to the problem of farm dam sizing for a given set of catchment characteristics and given probabilities of supply failure. As a result of undertaking this work, the yield of small ungauged catchments can quickly be determined and farm dams can be appropriately sized. This information is useful to farmers when constructing new farm dams and to catchment managers when assessing applications to construct new farm dams.