Sudden water pollution in the central urban area of Nanyang City generally happens in a basin-wide area with great uncertainty and long-term impact. It is hard to tackle with and requires complex entities for the emergency response. To improve the ability of emergency response management for sudden water pollution and the ability of disaster prevention and mitigation in urban area, a WebGIS-based management system and information service system for water pollution in the city is established. Measures including promoting crisis awareness, establishing emergency management system, formulating emergency planning, organizing regular training and maneuver, publishing information timely, as well as pollution control and treatment in later period are also proposed.