Soil and water conservation is the application of engineering and biological principles to the solution of soil and water management problems. The conservation of natural resources implies utilization without waste while maintaining a continuous profitable level of crop production and while improving environmental quality. It this, necessary to develop economical systems that meet these requirements. The engineering problems involved in soil and water conservation may be divided into the following topics: erosion control, drainage, irrigation, flood control, and water resource development and conservation. Although soil erosion takes place even under virgin conditions, the problems to be considered are caused principally by human exploitation of natural resources and the removal of the protective cover of natural vegetation. Urban-rural interface problems are even more serious because of high population density and increased runoff caused by severe changes in land us