Use of agricultural soil survey maps for engineering geologic mapping

Geologic mapping for construction of canals and pipelines as well as for irrigation and drainage developments, etc., is both expensive and time consuming. Due to the frequent uncertainty of the final alinements and location of project structures, the areas mapped during reconnaissance and feasibility studies may be disproportionately large. Experience developed from several projects in the Central Valley, California, indicates that National Cooperative Soil Survey (NCSS) "agricultural" soil maps provide an excellent, readily available base for "office compilation" of engineering geologic maps for the reconnaissance-feasibility stages of an investigation. Such soil maps are made essentially for agricultural use, but reflect the character and composition of underlying formations, topography, and other data valuable to engineering geology.--Modified journal abstract.