The new ethic of sustainable development extends the main principles of water resources management. Computer-based decision support systems are explored in order to identify their role in the implementation of these principles into water resource management practice. The first part of this research (see the previous article in this issue) has demonstrated that sustainable development is a global concept that needs to be made reality in any component of every decision support system to be developed for successful management of water resources. This article presents four successful case studies of decision support systems (DSSs) for sustainable management of water resources. Development of a DSS for sustainable water resource management is seen as a process, and while the issues covered in these four examples are the priorities in their respective domains, it is certain that new issues will emerge in different fields of application. So, what is presented here is thus a snapshot of current best efforts