From the view point of building an "economical society",this paper proposes that a traditional open evaporation tank for ex pressway construction changes to a buried storage tank so as to make full use of rainwater for irrigation of roadside fields or plants along the expressways.This may not only convert waste water to useful resources,but also improve the inelegant landscape resulted from open evaporation tanks.The paper also providesst ructural drawings of the desilting basin and the storage tank with volume of 147 m³.