Simplifying formulas that are used for calculations and design are the aim of researchers. For present work, the approach to distinguish the flow under sluice gate was conducted in a laboratory. The extensive experimental program was done to collect fifty-four data points for both free and submerged flow conditions. The data included different discharges, gate openings, flow depths at upstream as well as the flow depths represent a tail water and at a contracted section for downstream. The collected data are analyzed according to a problematic that may encounter in the field, to present a more straightforward (but with acceptable accurate) practical features equations and charts. Based on the proposed formulas, five methodologies were introduced as a guide for site engineers and beneficiary farmers. As results, necessary calculations should be followed for the purpose of the successful management of surface irrigation project by an investment of the available water to be delivered with minimizing or preventing head losses to ensure acceptable irrigation efficiency up to the farthest outlets.
