Abstract: This study aims at exploring and evaluating the effectiveness of water environment improvement strategies, which is crucial for the optimization of urban drainage projects layout.We selected the drainage area of Dongfeng Lake in Yueyang City as the study area, and constructed a target accessibility model according to local drainage system characteristics.The effectiveness was evaluatedamongnine water environment improvement strategies, including storm sewer outlet control, source control, separated sewer system construction, retention tank, waste water treatment plant upgrading, and four comprehensive treatment strategies.The results show that the target accessibility model can not only reproduce the current scenario in Dongfeng Lake drainage area, but also evaluate the effectiveness of the improvement strategies.The mean relative error of COD concentration is 0.034.For the single strategy, the retention tank strategy can reduce the volume of overflow by 23%,and the source control strategy plays an important role in reducing the peak of pollutants and the volume of combined sewer overflow.By contrast, the comprehensive strategies can better improve the water quality, especially the ninth strategy can maintain the class Ⅳ surface waterin Dongfeng Lake.