This study was concerned for steady flow in open canals of different flow conditions that may exist in irrigation system. To achieve this objective, AL-Ibrahim Canal Located South of Iraq has been selected from numerous irrigation systems having deficiencies between demand requirements and actual supply, due to a problematic of distribution and management. The field works consists the measurements of stages at outlets,at upstream, and at downstream head regulators .The study adopted nineteen actual cases of discharge along six months, two or more measurements at each month during the study period,between November 2013 to April 2014.The main objectives of the present study are; analysis the actual operation of irrigation canal and evaluated indicators then the HEC-RAS model was applied to achieve these objectives. Themax. stage and discharges measurements at head regulator during the study period was4.415 m3/sec at Jan.2014,where it less than a target discharge , so the outlets along canal should not be operated at the same time especially if the gate of the outlets are fully opened , because for entire operation numerous outlets will take discharge higher than the target.The study has shown that it doesn'toperatethe channel and access to the standard of performance but several scenarios have been prepared depending on the discharge at head regulator.