Research about Alberta, British Columbia, Idaho, Montana, Oregon, Washington

Ground water of the Columbia Basin

Part of the water that infiltrates from the surface reaches a zone of saturation whence it percolates toward the outlet and thereby is delayed in its course to the sea. This ground water is one form of natural storage which has different degrees of effect on stream flow in different segments of the Columbia River basin. As a whole the Columbia River receives a substantial part of its base flow from the discharge of ground water. The inflow from ground water differs materially in each of the six general terrain areas, which are described briefly below.