California Agriculture

Northern California has extensive areas of irrigated pasture, which provide critical summer forage for livestock. In many of these systems, water is diverted directly from a stream into ditches or pipes and transported to individual pastures, where it is applied as flood surface irrigation. Our case study of discharges from irrigated pastures on Willow and Lassen creeks in Modoc County illustrates an assessment and monitoring approach for land managers and natural-resources professionals working to resolve water-quality impairments related to agricultural discharges from similar systems. We report correlations between four indicator variables measured in the field and the variables determined in the laboratory, to evaluate the potential for employing a strategic combination of the two.