Mémento du gestionnaire de l'alimentation en eau et de l'assainissement is a comprehensive French-language handbook designed for professionals responsible for water supply and sanitation systems. First published in hardcover by Lavoisier (under its Tec & Doc imprint) in November 1993, the volume spans approximately 1,262 pages and provides detailed technical guidance, regulatory references, and best‑practice procedures for the planning, operation, maintenance, and monitoring of municipal water networks and wastewater treatment facilities. The work draws on the expertise of Lyonnaise Eaux, a leading French water utility, and incorporates contributions from engineers, chemists, public‑health specialists, and hydrologists. It includes tables, diagrams, calculation methods, and worked examples that support day‑to‑day decision‑making and long‑term infrastructure planning. Intended for engineers, technicians, managers, and other professionals in the water sector, the mémo serves both as a practical field guide and as a reference text for academic programs in environmental engineering and public works. Its enduring relevance is reflected in continued reprints and its citation in industry standards.