A variety of tools such as databases for knowledge management, Geographical Information System for geospatial data management, Decision Support System can be employed for disseminating information. There is a lack of a single system that would allow data to be readily accessible, more easily combined and more flexibly modified to meet the needs of decision-making. This book focussed on the development of a hydro based information system compatible to OpenGIS that can do analysis and address issues related to water resources engineering. The Hydro Information System comprises of programming language such as Java with JfreeChart package, OGIS compatible MySQL, PostgreSQL Database and visualization tools such as OpenMap. The system is used as an application that can take input data through a Java based interface, retrieve data from the database and do analysis and store the output data back into the database. The Hydro information system was evaluated and validated by applying a number of examples from water resources engineering that includes low flow estimation, non-point source pollution loads estimation, vegetation models using remote sensing and ground water contamination.