A research project, solicited and funded by the Water Research Commission and the Dept. of Water Affairs (Working for Water Programme) and led by the CSIR, has been commissioned to investigate rates of water-use and growth within indigenous tree systems. The main objectives of the project are to improve our knowledge of how much water indigenous tree species use, how efficiently they use that water (e.g. utilisable timber produced per unit of water used) and what potential exists for indigenous tree species to be planted more widely in South Africa. Over the next 5 years, growth and water-use measurements using specialised techniques (e.g. sap flow and energy balance methods) will be conducted in natural indigenous forests (mixed species / mixed ages) and in indigenous plantations (single species / single age) where possible.