One approach to the introduction of computational material to the classroom is to supplement a textbook with modern computer codes. Unfortunately most codes are expensive, designed for commercial use, without source code and may require special software. Visual Hydrology provides a cheaper and simpler alternative, supplying computational exercises that can be fully assimilated by students, and allowing them to activate, understand and reproduce modern computer code. Visual Hydrology aims to: explain the structure of modern object-oriented computer code provide the source code for worked examples numerically check the worked examples used in text show how worked examples can be used with alternative data describe and reference the underlying theory provide additional exercises with each worked example use Microsoft Excel software alone Requiring only a basic knowledge of Microsoft Excel, this Primer teaches the use of modern and readily-available computer code for engineering computation. Visual Hydrology demonstrates codes for common and practical examples used in hydrological engineering, and will be a valuable resource to students, research workers and consulting engineers in the water-related sector. Examples of source code to accompany this publication can be downloaded by clicking here.