Climate change is very influential in human life. Climate change has a strong correlation with water usage and its existence in the world. This research was conducted to analyze the water efficiency as an effort to modify climate change. The research area was conducted on the social cluster buildings campus of Semarang State University (UNNES), Semarang, Indonesia. The building of social clusters consists of three faculties, the Faculty of Social Science, the Faculty of Economic, the Faculty of Law. The research area was chosen due to located on the hilly preserved area. The lack of management will lead to worse conditions, and it will harm the surrounding area considering its area function. Database simulation on this research was analyzed by using the EDGE application that was initiated by the World Bank. By using the EDGE application, the project analysis is getting faster, easier, efficient, and more affordable. The result revealed that water efficiency in social cluster buildings is 0 %. This percentage was classified as a low score under the minimum percentage of water efficiency standards (20%). Based on the low-level water efficiency, this research carried out five-level simple scenarios considering the condition of building management in the social cluster of Semarang State University. Furthermore, by implementing the water efficiency scenarios, the percentage increase up to 37.86% with 19,095.02 m3/yr of water-saving calculated by EDGE application and extra 82,250 m3/yr calculated by manual calculation.