This is a specialized study designed to serve as a guide to water and related land resources development planning. An expanding economy requires more resources or more intensive resource utilization. As demands for resources increase, the increase in their supply can often be attained only by developing more costly sources or by utilizing resources more intensively. In particular, future demand for water looms large. Assuring that demands for resources will be satisfied in the best manner requires comprehensive development plans. These plans should in turn be based on the character and growth of the basin's economy. The objective of the Economic Base Study is to provide the basis for determining the scale, sequence, and timing of water and related land resources development. These determinations are based on estimates of future economic activity within the basin and the characteristics and size of its population. In estimating the basin's future economic activity, regional, national, and foreign trade in goods and services are recognized. Exports of basin products enhance the economic growth of the basin. The economic parameters projected in this study may be used in determining the need for each of the resource planning objectives. Useful economic parameters include (1) population and its characteristics--age, sex, and per capita income--for estimates of visitor-day use in fish and wildlife, and recreation studies; (2) output of industries using large quantities of water and power, for estimates of municipal and industrial water and power requirements; and (3) changes in urban, industrial, and agricultural development.