Nevertheless, the achievement of sustainability may not meet the water quality required by the regulations. The water quality is an important concern of the local government and residents in the study area. Therefore, a specific restoration goal for the water quality is set as a constraint condition to be satisfied after the restoration of ecosystem. Water quality goal was determined according to the requirements of government regulations. The surface water quality of Type III and Type II are consistent with the low and high restoration levels, respectively [25]. The restoration levels are delineated in Table 6. The sustainability value should be more than 0.618 and the surface water quality should be set as at least Type III for the low restoration level [25]. The sustainability value should be greater than 0.679 and the surface water quality are required to be above Type II for the high restoration level [25].