Description of the ground-water flow system in the Portland Basin, Oregon and Washington

An increasing dependence on ground-water resources in the Portland Basin has made it necessary for State and local governments to evaluate the capability of the ground-water system to meet present and future demands for water. This report describes the regional ground-water system and provides a conceptualization of the aquifer system. Aquifer geometry, recharge, ground-water flow directions, ground-water/surface water relations, water use, and water-level changes with time are presented.