-

In recent years, flood control projects have been widely applied throughout the country. An important aspect in these projects is a great volume of labor and therefore trends cost involved. Prioritizing the sub-watersheds is practically performed traditionally. The goal of this research is to propose a mathematical method to prioritize and select a better choice. Overall, in these issues, we can us_ different multicriteria decision making (MCDM) method. Most MCDM methods automatically line up the selections and provide the result without incorporating the decision-maker. Among those, the utility additive (UTA) method with greater flexibility was considered in this study since it gives a
greater importance to decision maker. The UTA method constantly asks for selection of the decision
maker through some steps using piecewise linear programming. In this study, 49 sub-watersheds of the Kan River in Northwest of Tehran were evaluated according to 50 years return period of flood, lag time, and fatal-cost damage. The results show that despite the multi-component goal, the K3 (Keshar) sub-basin is number one with regard to practicality. This method can effectively be used in these projects to reduce the high cost in low priority sub-basin.