A simple, direct and efficient semi-theoretical approach was developed to solve the hydraulic design problem of a horizontal or uphill sloping, single-diameter multi-outlet pipe. The proposed simplified model is essentially a design concept ensuring the hydraulic criteria for desired level of water application uniformity and allowable pressure head variation along with the limitation for economical pipe design. In the present technique, one can directly determine the smallest pipe size, pipe length, operating inlet pressure head and corresponding design parameters (pressure head variation, downstream end pressure head, total or friction losses and alternate uniformity expressions) for a desired level of water application uniformity with known design variables. For practical purposes, the design charts were also prepared to quickly determine the required design parameters. A comprehensive comparison test was applied for various design combinations. The examination results reveal that the proposed design technique is sufficiently accurate in comparison with the previous analytical and numerical procedures. Copyright (C) 2008 John Wiley & Sons, Ltd.