We discuss the problem of programming the optimal operation of an aquifer system hydraulically linked to a river, using a set of predesigned hydraulic structures, in order to meet agricultural requirements. The focus is on two fundamental aspects: (1) the choice of a model that adequately reflects the physical, dynamic behavior of such a system and possesses characteristics allowing for the treatment of the problem through optimization techniques, and (2) the formulation of the problem as an optimization program. The model includes a physical component, based on the influence coefficient (inpulsional response) concept and the principle of superposition, and an agricultural production function, elaborated in such a way as to reflect the dyanmic process of plant development, that is, the seasonal life cycle of the crops and the effect of changing hydrological conditions on the latter. Results obtained on a test scenario illustrate the approach. ¿ American Geophysical Union 1993