The book "Hydroinformatics Tools for Planning, Design, Operation and Rehabilitation of Sewer Systems" offers a comprehensive analysis of the application of hydroinformatics in the planning, design, operation, and rehabilitation of sewer systems. It is aimed at professionals in the fields of environmental planning, engineering, and urban management who are seeking innovative approaches to improve the efficiency and effectiveness of sewer systems. The experienced authors illuminate the business and information technology requirements for managing urban drainage systems and provide valuable insights into data collection and archiving. The book also addresses the modeling of catchment areas, hydraulic aspects of sewer systems, as well as wastewater quality and the operation of treatment plants. Another focus is on real-time control and operation of sewer systems, along with their maintenance and rehabilitation. Intelligent decision support systems are introduced to optimize the urban drainage process.