Irrigation Tailwater Loss and Utilization Equations

Allowing irrigation tailwater runoff is the commonly accepted practice for fully irrigating the lower end of graded furrows or borders. Irrigation-system water losses are minimized by proper balance between tailwater losses and deep percolation losses. Criddle, et al. recommended an irrigation advance time equal to one-fourth of the application time. To reduce tailwater losses that occurs without a cutback furrow stream. Bondurant presented design criteria for tailwater recovery systems and recommended operating the systems to achieve a reduced furrow stream input. Knowledge of the relative importance of design variables and the ability to place bounds on tailwater loss and recovery aids the engineer with limited design information. This paper develops equations that show the relative importance of the variables affecting tailwater loss and utilization.