Artificial Intelligence (AI) technology has the potential to further improve the performance of the environmental decision support systems. This produces a new generation of such systems called, Intelligent Environmental Decision Support Systems (IEDSSs) and yielding a new interdisciplinary field of research. This field includes; artificial intelligence, knowledge management and computing, machine learning, management and environmental sciences. This paper investigates and discusses the role of the AI concepts and methodologies in developing the IEDSSs. This paper is to discuss the following aspects: knowledge management and engineering, reasoning methodologies and expert systems.