SUMMARY
This study was carried out to evaluate the irrigation system performance of the first and second stage irrigation areas of Daphan Plain, which is constructed and transferred to Daphan Irrigation Association by The State Hydraulic Works in Daphan Irrigation Project area for the years 2012-2016. As a result of the research, it was determined that the annual net water supply ratio was between 7.10 and 9.90 for the real plant production area and 2.19 to 2.60 per year for the total schemes area which was ready to irrigation applications. The net water supply ratios were ranged from 3.20 to 4.20 for irrigated land while it was varied from 0.93 to 1.10 on the condition of whole area were planted. Sustainable irrigation area ratio is realized between 24.53% and 33.15% and the ratio of realized production values are between 19.34% and 26.13%. While the profitability ratio is between 4.30 and 9.28, the financial efficiency ratio is between 17.69% and 46.82% and the financial sufficiency ratio is between 106% and 145%, the collection rate of irrigation water fee is between 20.66% and 34.37%.