A mixed integer programming model for planning water resources investments is presented. The model is a sequencing model applied to the Vardar-Axios river basin in Yugoslavia and Greece. The structure of the model is outlined, and computational experience is described. The size of the model presented some difficulties, which are discussed along with the results to date. The experience with this model points to areas where further research is needed.Researchl supported (in part) by the U.S. Army Research Office (Durham) under Contract DAAG29-76-C-0064.