This project involved the purchase of equipment to measure the surface water inputs and outputs of two commercial scale cotton fields. Cotton is grown on each field in alternate years and fallowed in the off year so that it was possible to compare the hydrologic behaviour of both cropped and fallow conditions. Irrigation water and rainfall inputs and tail water outputs were measured. Irrigation water input was measured with an open flow meter installed in the head ditch of the field containing cotton. Rainfall quantity and intensity were measured with a tipping bucket rain guage connected to a data logger. Outflow of surface water from both fields was measured with v-notch weirs and water depth sensors coupled to data loggers. A computer program has been written to process data logger output into a form for graphing and analysis.