Description:
The City of Philadelphia has migrated metadata for this data set to the City-wide Metadata Catalog. For any questions about the migration and administration of the Metadata Catalog, please contact maps@phila.gov.
To view the metadata for this layer, please visit: https://metadata.phila.gov/#home/datasetdetails/557f30c6dcec614c29ce8b6d/representationdetails/557f30e3c579ea311699bb49/
Below is information copied automatically from metadata.phila.gov:
This layer shows the waterways in Philadelphia and its contributing watersheds. It also shows the Delaware River and Delaware Bay downstream of Philadelphia. The data is comprised of a combination of USGS's National Hydrography Dataset stream flow data, planimetric data digitized by Sanborn in 2004, and data provided by PWD field survey work.
Development Process:
This layer shows the waterways in Philadelphia and its contributing watersheds. It also shows the Delaware River and Delaware Bay downstream of Philadelphia. Initial data was captured from orthoimagery flown in 2004 by Sanborn. A combination of automated feature extraction (Planimetrics), desktop digitization and field survey is the basis for this dataset, which is updated regularly by PWD. As new orthoimagery reveals changes in stream geometry, adjustments are made to the polygon and centerline layers to reflect reality. The resolution and accuracy of newer orthoimagery improve over time, allowing for more detailed feature extraction.
Office of Watersheds staff maintains the feature classes regularly, making geometric and attribute changes or adding new streams or infrastructure. The database is set up to reflect various forms of infrastructure along streams such as culverts, bridges, dams, and channelized segments. Additionally, unique segment and reach IDs were added to correlate to PWD Fluvial Geomorphology stream studies. USGS NHD Stream Names and IDs have been carried over, and stream order classifications using both the Shreve and Strahler methods are coded. See the table below for more detailed attribute entity information.