Evaluation of throughflow interceptors for controlling secondary soil and water salinity in dryland agricultural areas of southwestern Australia: I. Questionnaire surveys

Increasing soil and water salinity in southwestern Australia is a major social, economic and environmental problem. Hydrological imbalances following extensive clearing of the natural vegetation for agriculture have redistributed soluble salts into soils and streams. Interceptors have been designed by farmers to control the throughflow component of this hydrological imbalance, to reduce waterlogging of low-lying areas, and thus to ameliorate salinity problems.Farmer interviews show that, to date, interceptors have only partly achieved these objectives. Many interceptor systems are insufficiently comprehensive and leakages are common. Further, too short a period of time has elapsed since interceptor construction to have reversed the severe deterioration of soil properties.