Delaware Water Gap is a borough in Monroe County, Pennsylvania, United States. It is located adjacent to the Delaware Water Gap, the pass through which the Lackawanna Corridor and Interstate 80 run across the Pennsylvania-New Jersey border along the Delaware River.The population of Delaware Water Gap was 746 at the 2010 census.HistoryThe Delaware Water Gap (Delaware, Lackawanna and Western Railroad station) was added to the National Register of Historic Places in 2002.GeographyDelaware Water Gap is located at .According to the United States Census Bureau, the borough has a total area of 1.7sqmi, all of it land.