The potential transfer of water from the Mullica River Basin prompted a joint study by biologists and engineers to determine (1) the minimum average monthly streamflow necessary to maintain an appropriate ecological balance in the river-bay system and (2) the optimum combination of groundwater-surface water pumping to maximize yields and to meet the ecological criteria. This report describes the geological and hydrological characteristics of the Mullica River Basin and explores engineering means of withdrawing water supply under somewhat unusual circumstances. A chance constrained linear programming model for the conjunctive use of ground- and surface water was used, along with groundwater aquifer-stream system equations to obtain rates of optimum withdrawal of surface waters and groundwater consistent with specified objective functions and sets of physical and operational constraints. The physical constraints are those given in terms of minimum streamflow residuals. Optimization was obtained using linear programming techniques. (Modified author abstract)