soil conservation, earthworks, drainage, grade banks, grassed waterway, gully, drains
In view of the great diversity of hydrological conditions encountered in the field, and the relative paucity of information with which to design soil conservation earthworks, it is frequently not possible to quantify all aspects of hydrologic design. It remains for the practising soil conservationist to search for a reasonable solution to a problem which is most appropriate to the situation, location, information and skills. The equations in this Manual provide the best available estimates of flow rates and volumes for carrying out design but it must be recognised that the information has come from a relatively limited data set, and that a significant amount of variability in runoff estimates remains unexplained by the equations. The observations of landholders during previous runoff events and the experience of local Departmental personnel are particularly valuable and should be used in conjunction with the design equations. It is not intended that the material in this Manual will be adequate in all situations. In complex or high risk situations, assistance should be requested from specialist personnel of the Division of Resource Management.
Bligh, K J. (1989), Soil conservation earthworks design manual. Department of Agriculture and Food, Western Australia. Technical Bulletin.