There are a number of large river systems within Underwood Conservation District (UCD) boundaries including the Klickitat, White Salmon, Wind and Lewis Rivers. UCD is set in a unique location that spans both sides of the Cascade Mountain Range. Annual rainfall within our district varies significantly, ranging from 99 inches per year on the west end to about 20 inches per year on the east end.
Surface water is water on the surface of the planet such as in a stream, river, lake or wetland. Surface water is replenished by precipitation through overland flow (runoff) and by ground-water. Surface water is lost through evaporation, seepage into the ground, transpiration (by plants) and extraction by humankind for agriculture, living, industry and more.
Groundwater is the water present beneath Earth’s surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table.