A lateral canal in the southwestern U.S., that was comprehensively monitored, operated under flexible delivery scheduling. Over a two-year period 286 events were recorded, at nine farm turnouts. Data from field on eproms and written computer programs were used. Delivery uniformity was measured as the flow coefficient of variation (CV). The more uniform was the delivery, the smaller the value of CV. A numeral of variables understood to explain these sources were measured. Models were developed as CV =/ (variable) from the Statistical results of univariate analysis. Analysis of variance (ANOVA) was used for the class variables and Regression was used for continuous variables. Deliveries flow rates irrigations duration and Deliveries to farm turnouts locations have significant impact on uniformity while number of irrigations concurrent to one being observed, level of the main canal fluctuation, delivery began time of day, and the ditchrider on duty were not shown to be significant.