The Geofabric Surface Catchments product is derived from the National Catchment Boundaries (NCB) V1.1.4. This data defines a catchment for every stream segment containd within the Geofabric Surface Network product according to the GEODATA Nine Decond Digitial Elevation Model (DEM-9S) Version 3. These stream segment level boundaries may be used individually or in aggregation. The product is designed to represent geographic surface boundaries that have a hydrological relationship to surface water features. The NCB Level 1 and NCB Level 2 features are the top two levels in the NCB Catchment hierarchy and have been provided as polygon boundaries. This product contains one Geofabric feature type called Catchment. It also contains three NCB feature types including: NCBLevel1Drainage Division, NCBLevel2Drainage Basin and NCBPfafstetter