ABSTRACT
Groundwater, streams, rivers, lakes, and reservoirs are invaluable natural resources in the United States. They supply drinking water, supply water for irrigation and industry, are a source of natural beauty and recreation, and are a mode of transportation. The use of water resources and the establishment of water use priorities have always been controversial in the United States. Water for irrigation and removal of excess water is critical for maintenance of high-quality turfgrass on golf courses. Water is the dominant factor that controls the structure and functions of managed and natural ecosystems. Precipitation, irrigation, interception, infiltration, surface runoff, subsurface flow, soil water balance, evapotranspiration, drainage, and deep leaching to groundwater are essential components of the hydrologic cycle. The movement, or percolation, of water through soil is determined by the hydraulic conductivity of the soil and the hydraulic gradient.
