Geospatial Datasets of Water Surface Elevation and Water Depth in New York City, NY Associated with the Remnants of Hurricane Ida – September 1, 2021

The remnants of Hurricane Ida produced significant rainfall over the five boroughs of New York City (NYC) for several hours on September 1st, 2021. The long-duration, high-intensity rainfall resulted in extensive inundation of streets, buildings, subways, and other public spaces. In response to a Federal Emergency Management Agency (FEMA) mission assignment, the U.S. Geological Survey (USGS) identified and surveyed high-water marks (HWMs) at 83 locations across NYC to document the peak water elevation in impacted areas (Capurso and others, 2023).

This data release contains maps of water-depth and inundation extents for areas within 250 meters of surveyed HWM locations. These depth maps assume a constant water-surface elevation across the landscape around each HWM and show where potential inundation may have occurred during the rainfall event. The water depth data is presented as tiff files (raster format), in feet above land-surface elevation (Quantum Spatial, 2018) and above or below the 1st floor elevation of buildings (Department of City Planning (DCP), 2023).

Users are advised to read the related external resources below and processing steps within the metadata file to better understand the limitations of these data.
 
This data is accessible as an online webmap: 
https://usgs.maps.arcgis.com/apps/mapviewer/index.html?webmap=43dd2a672…