Scottish Water's Sewer Catchments

Scottish Water Sewer Catchment Areas are also known as Drainage operational Areas (DOAs). A Drainage operational Area (DOA) is defined as the geographic area which encloses all the wastewater assets, properties and ground surfaces that deliver flow to a single Sewage Treatment Works (STW) or a Public Septic Tank (PST). It also includes the Surface Water assets which serve those properties and surfaces.