This 348-page handbook is available in English and Spanish. The target audience includes anyone concerned with water quality monitoring with a scientific, managerial or engineering background, including field staff. This book covers the entire monitoring process providing detailed guidance for implementing a monitoring network with step-by-step descriptions of field and laboratory methods. An overview of the principles underlying hydrological, chemical, biological and sediment measurements together with their importance and relevance to water quality monitoring is also included. These guidelines will be particularly relevant for field use in developing countries and provides: a protocol for design and implementation of monitoring surface and groundwater; details of sampling and analytical methods; guidance on data analysis and presentation.