This paper studied the development of hydrological and water resources information system of Lin’an City from the design principle, whole framework design, system function design, etc. Based on B/S model, the key problems should be solved, which include the efficiency of massive hydrological and water resources data querying, system response speed for high number of concurrent user access and real-time transmission of early warning information by applying open source framework technology like Quartz, Ehcache and WebSocket. The results show that, the hydrological and water resources information system for Linan City can provide such analytical processing tools as water, rainfall, hydraulic structure behavior, water resources information inquiry, release of early warning and forecast, document and report forms autogeneration and hydrological station maintenance and so on, achieving the intellectualization of hydrological daily operation. Finally, real-time hydrological and water resources information services can be provided to the decision-making departments and the public.