本文從實務的覯點，發展一套都市雨水下水道設計標準檢討改善之經濟評估之方法。由於政府財政目標與其保障人民生命財產免於損失的目標常會互有衝突，因此如何在二目標間取得一個平衡，找出最有效且最適的方案，便成為政府施政時的一個主要考量。過去實務上針對都市雨水下水道來討改善的經濟評估往往過於簡略，以致經常招致一般人民的疑慮。本文以成本效益分析及雨水下水道實務及理論為基礎，建構一套實務上可行之經濟評估方法與步驟，希望能提供相關單位及學者在從事都市雨水下水道容量標準分析檢討之參考。

　　　　　This study develops a practically feasible approach for locating the mo-st feasible urban drainage investment project. Based on both the cost-benefitanalysis and the theory and practice of urban drainage analysis, we successfullyconstructed an economic evaluation framework and procedures which can be used bygovernment agencies in deciding on the most favorable project among severalalternatives. The single-objective results generated using the approach mightnot be the only consideration that the government will take into account whenmaking the investment decision. The results, however, may provide the governmentwith useful information and serve as a major reference point with whichcompeting projects can be compared.