The purpose of this appendix is to appraise the present municipal and industrial water supply situation, to analyze its future needs and development potential, and to evaluate the needs of subareas as a basis for making recommendations for measures which will serve those needs. Consideration of municipal and industrial water supply as a part of a comprehensive plan for development and management of water and related land resources is essential to provide a means for orderly development of water supplies. The scope of this appendix limits projection of municipal and industrial water supply requirements to the years 1980, 2000, and 2020. Appraisal of the 1980 requirements includes consideration of quantity, quality, and seasonal variations of supply and demand. The need identified is of an immediate nature and may be directly related to the development of a comprehensive plan for readily foreseeable developments. The long-range plans, which are naturally more conjectural, are more general in nature and point toward the needs of major subareas of the basin. The study area is confined to the Willamette Basin; however, the strong geographical and economic interrelations and interactions between the Willamette Basin, the Pacific Northwest, and the Nation will influence the level of municipal and industrial water demand in the basin. As an example, increased market area population will result in an enlarged market for processed food. Additional food-processing capacity will result in an increased demand for process water and water for the additional population supported by the industrial employment.

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.

The Willamette Basin is one of the better watered regions of the United States. The average annual precipitation of 63 inches results in a volume of more than 40 million acre-feet of water falling on the basin annually. Of this amount, about 26 million acre-feet runs off in the principal streams that drain the area. Most of the precipitation and runoff occurs during a few months in the winter, and natural water supplies are deficient during the late summer and early fall. Because of the diverse terrain, both precipitation and runoff are distributed unevenly. For this reason, it has been necessary to construct facilities to store the surface water and to drill wells to tap the ground water. As the population and economy of the basin grow, many additional water developments will be needed. The purpose of the Willamette Basin Comprehensive Study is to develop information on future water and related resource needs and to prepare a plan for meeting those needs. This appendix contains a description of the water resources, their distribution, and their variation at different periods of time throughout the Willamette Basin. These resources are described in terms of the climatic, geologic, and other environmental factors that influence and control the occurrence of water. The appendix provides statistical and interpretive hydrologic data necessary for broad-scale water-resources planning. These data are essential to the development of plans for meeting the basin's water needs and solving its water problems. (Author).

Population estimates indicate that by 2020 Willamette Basin's population will more than triple; thus, the need for water control and for water and related land resource development will greatly increase. Although much has been done, serious problems of control and conservation of water remain unsolved. Several major existing projects and project authorizations do not include specific provisions for the potential new primary project functions of fish and wildlife enhancement, water supply, water quality control, and recreation. Serious flooding on the larger streams and main stem has occurred as recently as 1964, while many smaller streams flood annually. There is substantial interest in additional irrigation development. There are a number of areas requiring drainage and erosion control. A need and an opportunity exist for enhancement of the extensive anadromous fish resource. Future municipal and industrial water supply needs will require additional storage. Serious water pollution problems exist and will continue even with high levels of treatment at the waste sources; thus, additional streamflow will be required for water quality control. The growing population will create an increased demand for recreational facilities. Present in-basin power development does not meet basin needs; however, power supply is based on optimum use of regional power resources whether within or outside the basin. Also, there may be a need for increased navigation development on Willamette River. In summary, the rapidly expanding population will bring the full range of water and related land resource problems and needs in increasing intensity.