This paper presents a Supply and demand model for seawater desalination powered by Incineration of municipal solid waste to complement the freshwater supply ill a drought-affected area. The model follows a dynamic systems approach with control theory as a basic discipline. This approach aims at developing an efficient model in it simpler understandable way to reduce efforts required for modeling complex multi-domain problems. The modeling approach is complemented with other modeling techniques Such as artificial neural networks (ANN) to overcome a number of modeling difficulties. Ill this paper. the model Is applied to the city of Gold Coast, Australia, and simulation results arc presented its an application case. Our model is designed ill Such a Way that it call be adapted to other local conditions by changing the local parameters and data for whatever the regional case.