TABLE OF CONTENTS The hydraulic capacity of the soil to accept and transmit water is crucial to the design of rapid infiltration (RI) systems and important in the design of most slow rate (SR) systems. The important hydraulic factors are infiltration, vertical permeability (percolation), horizontal permeability, groundwater mounding, and the relationship between predicted capacity and actual operating rates.
The hydraulics of soil systems are controlled by the physical and chemical properties of soil. Important physical properties include texture, structure, and soil depth. Chemical characteristics that can be important include pH, organic matter, and exchangeable sodium percentage. Information on these soil properties and on soil permeability can be obtained from the Natural Resources Conservation Service (NRCS) and their detailed soil surveys.
Soil surveys will normally provide soil maps delineating the apparent boundaries of soil series with their surface texture. A written description of each soil series provides limited information on chemical properties, engineering applications, interpretive and management information, slopes, drainage, erosion potentials, and general suitability for most kinds of crops grown in the particular area. Additional information on soil characteristics and information regarding the availability of soil surveys can be obtained directly from the NRCS. The NRCS serves as the coordinating agency for the National Cooperative Soil Survey and as such cooperates with other government agencies, universities, and agricultural extension services in obtaining and distributing soil survey information.
The physical properties of texture and structure are important because of their effect on hydraulic properties. Soil textural classes...
