This repository includes a Python file containing two functions that utilize ESRI's ArcGIS arcpy library. Users can input shapefiles (polygons) of sub-catchments and raster files of land use, land cover, and soil types. Additionally, another function allows users to input shapefiles (polylines) of the stormwater network, which include data on built material types and the age of infrastructure, to generate grouped categories of sub-catchments and stormwater conduits.