1 Introduction -- 2 Managing Water Resources for Urban Catchments -- 3 WP-A: Urban Water Resources Management -- 4 WP-B: GIS tool for planning decentralized sanitation -- 5 WP-C: Early warning system for lakes -- 6 WP-D: Environmental Information System -- 7 WP-E: Groundwater Systems.This volume addresses latest results of the Major Water Program of the Chinese Government which aims at the restoration of polluted water environments and sustainable management of water resources in China. It specifically summarizes the results of the BMBF-CLIENT project “Management of Water Resources in Urban Catchments” and the related MoST project “Key Technologies and Management Modes for the Water Environmental Rehabilitation of a Lake City from the Catchment Viewpoint” in Chaohu. The project is conducted by the Helmholtz-Centre for Environmental Research UFZ, Technische Universität Dresden, German and Chinese companies (WISUTEC, AMC, bbe Moldaenke, itwh, OpenGeoSys e.V., HC System and EWaters) in close cooperation with Tongji University, Nanjing Institute of Geography and Limnology of Academy of Sciences, Institute for Hydrobiology of the Chinese Academy of Sciences and the Chaohu Lake Management Authority. The book explains the development of concepts and solutions for sustained water quality improvement in Chaohu, combining urban water resource management, decentralized sanitation solutions, methods in water quality assurance, environmental information systems and groundwater modeling.