Our project to create a dataset of historical water bodies in New Jersey first began by finding and georeferencing maps of historical water bodies in the state. As detailed in a previous post, georeferencing determined the precise location of these maps on the Earth’s surface. This process required several months to complete. Once complete, the next step was to trace the water bodies in the historical maps using Esri’s ArcGIS Pro Geographic Information System (GIS) software to create digital representations, or features, of the historical water bodies (Esri, 2025).
The first step in tracing historic water body features in ArcGIS Pro was to create a feature class for each water body type. A feature class is a collection of features of the same shape type that share a common set of attributes (Esri, 2025). For this project, we created five feature classes: bay, lake/pond, river, stream, and wetland. The two feature class types used for this project were polygon and line. The bay, lake/pond, river, and wetland feature classes were polygon, and the stream feature class was line. The coordinate system for each feature class was set to “NAD 1983 (2011) StatePlane New Jersey FIPS 2900 (US Feet),” which is the coordinate system specific to New Jersey (NJDEP, 2021).
Once our feature classes were created, features were added to them using ArcGIS Pro drawing and editing tools. For our project, it is crucial that each water body feature be traced exactly so that any geospatial analysis they are used for is as accurate as possible. The tracing of historic water bodies for the entire state of New Jersey is a significant undertaking that is expected to take several more months. Only when the task is done and our dataset of historic water bodies in New Jersey is complete can our analyses begin.
References:
Esri. (2025). Overview of georeferencing. https://pro.arcgis.com/en/pro-app/latest/help/data/imagery/overview-of-georeferencing.htm.
New Jersey Department of Environmental Protection (2021). NJDEP MAPPING AND DIGITAL DATA STANDARDS (February 7, 2021). https://dep.nj.gov/wp-content/uploads/gis/njdep_gis_spatial_data_standards_edition_2_7_2021-1.pdf.