More Information: Rock Outcrops and Erratic Boulders
Updated: May 5, 2021
This overview of SNAD regulations is provided for informational purposes only—the actual regulations are much more complex than this overview. Contact the Bronx Office of City Planning, at 718-220-8500, with your specific project plans and a description of your property, to ensure that you comply with all zoning requirements. City Planning will guide you through the approval and permitting process.
The geology of Riverdale is displayed in its outcrops and boulders. These are of interest to scholars and residents, and are protected from modification as follows:
Rock Outcrop Glacial Erratic Regulation
An outcrop is a piece of bedrock An erratic boulder is a boulder that originated
exposed at the surface. elsewhere and was carried and deposited at its
current location by water or ice.
Modification or alteration of a
rock outcrop must always be Section
authorized by the City Planning 105-424
Erratic boulders of less than 6 feet in diameter Section
may only be moved. Erratic boulders "with a 105-423
diameter at any point of 6 feet or more" may
only be moved by authorization of the City