This addition to The Basics of Recharge and Discharge series deals with the surface water balance approaches that form the traditional basis of hydrological investigations. It explores both field methods and modelling methods for measuring or estimating the different parts of the water balance, including rainfall, evaporation, run-off and soil water storage.

The authors discuss the concepts required to understand a surface water balance result or to set up an experiment. As water balance studies can be both time-consuming and expensive, this report will give readers a better understanding of water balance approaches and the considerations before going into a water balance study for the purpose of deep drainage.