Design is a system which applicable to any kind of design where the emphasis to see everything unseperated, but as a unity is correlated one problem to each other.The object of research is customer information system application in Demak. Web-based GIS (WebGIS) is a Geographic Information System Applications (GIS) that is distributed in a computer network to integrate and disseminate geographic information visually to the World Wide Web. WebGIS compared with desktop GIS offers several advantages such as cost efficiency, workload efficiency of human resources for the installation, maintenance and technical support, trimming the learning curve for end users and excellence in the integration of spatial data and non-spatial Data.The results of this research is an Applications of GIS which has the web to give some facilities to customers of PDAM and offices to develop of the information systems