Modelled Estimates of Discharges for Urban Stormwater Assessments (MEDUSA) simulates heavy metal loading contribution from individual urban surfaces for a single rainfall event or multiple events (full year). The tool allows the estimation of total suspended solids (TSS), total zinc (TZn), total copper (TCu), dissolved zinc (DZn), and dissolved copper (DCu), from roofs, roads, and carparks. To run the tool, you need to select a surface type (roof, road, carpark), provide the surface area, select the surface material type, and provide climate inputs for a single or full year rainfall events. Climatic inputs include average rainfall intensity during event (INT), duration (DUR), antecedent dry days (ADD), and rainfall pH (~6.5 for New Zealand).
Further information on the tool and its application can be found in these scientific journal publications:
Predicting Event-Based Sediment and Heavy Metal Loads in Untreated Urban Runoff from Impermeable Surfaces