HowLeaky is an open source water balance, water quality simulation environment with a focus on comparative land management and use studies in Australia. A recent development integrates a simulation model with datasets and support material. The platform supports data archiving and sharing,  Resources include ready access to climate and soil hydrology descriptions, vegetation/soil management descriptors, nutrient and pesticide movement properties. The HowLeaky model operates at a point-scale using a daily time-step but is suited to integrating multiple land uses, topograpgy and management at the catchment scale.