Water footprint is an indicator to quantify the potential environmental impacts related to water. Current methods for the water footprint assessment can only obtain the results which are typically reported as a profile of impact category indicator results. Due to the diverse and incomparable results, the demand for a single indicator for water footprint assessment is highlighted in recent years. In this paper, an improved approach integrating water quantity and quality into a single indicator was proposed for water footprint assessment. Then, a case study for water footprint assessment of Zhejiang’s textile industry was analyzed with this approach. The results revealed that the comprehensive assessment indicator of water footprint (CAI_wf) of Zhejiang’s textile industry decreased more than 20% from 2008 to 2018. CAI_wf and endpoint indicator of water footprint (WF_end) obtained with volumetric water footprint approach depicted similar tendencies to the CAI_wf and WF_end obtained with impact-oriented water footprint approach. Among the three sub-sectors of Zhejiang’s textile industry, the CAI_wf of textile manufacture sector was the largest, followed by chemical fiber manufacture sector and clothing manufacture sector.