This paper derives the relation between productivity and pressure decline trends in a geothermal steam reservoir. At all stages of a geothermal project, the economics is affected by the rate of productivity decline. The rate of pressure decline becomes a critical issue when the reservoir pressure declines to the point that wells have to be flowed wide open to supply the turbine; at that stage, maintaining reservoir pressure and well productivity by redistribution and/or augmentation of injection becomes a stratcgic issue in field management. Therefore, the issues considered in this paper have significant practical implications.