This study presents the development of a simulation and decision support tool for assessing and comparing the hydrological performance of stand-alone and interconnected stormwater source-control techniques (SCTs) (green roofs, swales, retention basins or permeable surfaces) at the block and building scale, based on long-term time series. This tool is tested with a case study including various SCTs connected to a 600 m2 real green roof (Orléans, France), using rainfall and evapotranspiration time series over 2 years (2016-2017) measured with a 5 minutes time-step. Results led to compare the temporal variations of storage volumes (in the different retention zones), inflows (rainfall or upstream flows) and outflows (evaporation / evapotranspiration, regulated flowrates, infiltration flows and overflows) for each of the planned SCTs, throughout the 2 year simulation period. This tool also allows including simulations results from external pre-existing conceptual models.