This paper describes the development of a database and a website to support the newest version of Low Impact Development Rapid Assessment (LIDRA) model, LIDRA 2.0, a planning level model for assessing the cost-effectiveness of low impact development (LID) and addressing runoff-related problems in urban watersheds. LIDRA 2.0 is a web-based application that generates stochastic precipitation data from local historical data sets using a Markov Chain and bootstrapping method. Precipitation is applied to urban watersheds with parcel and street areas. LID scenarios and associated adoption and repaving rates are then used to perform multiple 30 year simulations, during which the difference in runoff is calculated using a water balance. The application needs to store parcel and street specifications and also offer a management interface, both of which must be accessible through the internet. The results of this are: an efficient tool to support LIDRA in terms of storage, retrieval and analysis of data and an integrated web application which allows users an easier way to input data and greatly reduce the time it takes to manage simulation modules via use of the graphical result interfaces that show the results produced. The technical underpinnings of this tool are highlighted using a small example.