The Willamette Basin Comprehensive Study of Water and Related Land Resources. Appendix B. Hydrology.
PACIFIC NORTHWEST RIVER BASINS COMMISSION VANCOUVER WASH
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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 basins water needs and solving its water problems. Author
- Administration and Management
- Hydrology, Limnology and Potamology