A collection of citywide Geographic Information System (GIS) layers that show areas of potential flooding scenarios under varying sea level rise conditions. Please see the New York City Stormwater Resiliency Plan for more information about the methodology applied to develop the maps. Please direct questions or comments to StormwaterResiliency@cityhall.nyc.gov.

This collection contains the following NYC Stormwater Flood Maps:

• NYC Stormwater Flood Map - Extreme Flood (3.66 inches/hr) with 2080 Sea Level Rise
• NYC Stormwater Flood Map - Moderate Flood (2.13 inches/hr) with 2050 Sea Level Rise
• NYC Stormwater Flood Map - Moderate Flood (2.13 inches/hr) with Current Sea Levels
• NYC Stormwater Flood Map - Limited Flood (1.77 inches/hr) with Current Sea Levels

Source Data: http://nyc.gov/stormwater-map

Citywide Geographic Information System (GIS) layer that shows areas of potential flooding under the Extreme Stormwater Flood with 2080 Sea Level Rise scenario. Please see the New York City Stormwater Resiliency Plan for more information. Please direct questions or comments to StormwaterResiliency@cityhall.nyc.gov.

NYC Stormwater Flood Maps:
https://www1.nyc.gov/assets/orr/pdf/publications/stormwater-resiliency-plan.pdf
http://nyc.gov/stormwater-map

The geodatabase contains a single feature class that shows three (3) flooding categories. The "1-Nuisance Flooding" (ponding depths greater or equal to 4 in. and less than 1 ft.) and "2-Deep and Contiguous Flooding" (ponding depths 1 ft. and greater) categories were created using hydrologic and hydraulic computer models and represent flood risk due to extreme rainfall. The third category, "3-Future High Tides 2080", shows coastal tidal inundation based on the NYC Panel on Climate Change 90th percentile estimates for the 2080's and is sourced from the NYC Flood Hazard Mapper. Please refer to the New York City Stormwater Resiliency Plan for more information on the purpose of the study, how datasets were developed, applications for this data, and other details.A coded value domain is used for the "Flooding_Category" field. See Column Info tab of the Data Dictionary for definition of each code.

The geodatabase contains a single feature class that shows three (3) flooding categories. The "1-Nuisance Flooding" (ponding depths greater or equal to 4 in. and less than 1 ft.) and "2-Deep and Contiguous Flooding" (ponding depths 1 ft. and greater) categories were created using hydrologic and hydraulic computer models and represent flood risk due to extreme rainfall. The third category, "3-Future High Tides 2050", shows coastal tidal inundation based on the NYC Panel on Climate Change 90th percentile estimates for the 2050's and is sourced from the NYC Flood Hazard Mapper. Please refer to the New York City Stormwater Resiliency Plan for more information on the purpose of the study, how datasets were developed, applications for this data, and other details.A coded value domain is used for the "Flooding_Category" field. See Column Info tab of the Data Dictionary for definition of each code.

New York City’s Municipal Separate Storm Sewer System (MS4) Stormwater Management Program is a multiagency effort led by the Department of Environmental Protection (DEP) to reduce pollution in stormwater runoff in the MS4 Area of NYC. This MS4 Map represents the known MS4 outfalls and drainage areas as of August 1, 2020 and provides additional data relevant to the MS4 Permit. The MS4 map only shows areas draining to the Municipal Separate Storm Sewer System. DEP also maintains combined sewer and sanitary sewer systems; these service area delineations are not represented on this map. More information about the MS4 Stormwater Management Program is available at www.nyc.gov/dep/ms4

This dataset contains the locations and detailed information of green infrastructure practices in NYC neighborhoods built primarily through NYC Green Infrastructure Program initiatives. Green infrastructure (GI) collects stormwater from streets, sidewalks, and other hard surfaces before it can enter the sewer system or cause local flooding. The GI practice data contained in this dataset includes the location, program area, status, and type of GI. This dataset is updated by the NYC Department of Environmental Protection on a monthly basis. The “Regulated_Projects” polygon layer contains Unified Stormwater Rule green infrastructure projects. This layer is part of a larger Green Infrastructure dataset. You can download the full dataset and the data dictionary below under “Attachments”. Source Data: DEP Green Infrastructure Program Map

The dataset represents the locations of combined sewer overflow (CSOs) outfall locations in NYS. Combined sewers collect stormwater runoff, domestic sewage and industrial wastewater in the same pipe and bring it to a wastewater treatment facility. They are designed to overflow during heavy rain events, causing excess water to be discharged directly into a waterbody. The public is advised to avoid contact while recreating within waterbodies with a CSO during or following rain or snowmelt. There are about 800 CSO outfalls in New York State. This is a decrease from about 1,300 in 1993, due to CSO abatements completed by the permittees.Service is updated annually and was last updated 11/6/2024.For more information or to download layer see https://dec.ny.gov/environmental-protection/water/water-quality/combined-sewer-overflow1. The NYS DEC asks to be credited in derived products. 2. Secondary Distribution of the data is not allowed. 3. Any documentation provided is an integral part of the data set. Failure to use the documentation in conjunction with the digital data constitutes misuse of the data. 4. Although every effort has been made to ensure the accuracy of information, errors may be reflected in the data supplied. The user must be aware of data conditions and bear responsibility for the appropriate use of the information with respect to possible errors, original map scale, collection methodology, currency of data, and other conditions.

311 complaint calls about clogged water outflows and sewer catchments. This information is automatically updated daily.

NYC Green Infrastructure Program initiatives. Green infrastructure (GI) collects stormwater from streets, sidewalks, and other hard surfaces before it can enter the sewer system or cause local flooding. The GI practice data contained in this dataset includes the location, program area, status, and type of GI.

Please visit nyc.gov/dep/gimap to view the DEP Green Infrastructure Map.

NYCDEP Citywide Catch Basins. Catch basins are an important part of New York City’s 7,500-mile sewer network. They are connected to underground pipes that channel stormwater from the street to one of DEP’s 14 wastewater resource recovery facilities, or directly into our surrounding waterbodies. DEP cleans and maintains over 150,000 catch basins citywide.

The SPDES Multi-Sector General Permit (MSGP), which is administered by the Department of Environmental Conservation (the Department), regulates stormwater discharges associated with industrial activity from a point source. The MSGP covers thirty one different industrial sectors which include activities such as mining, land transportation, and scrap recycling. The dataset displays information on facilities that have active MSGP coverage in New York State. Information included in the data set include the facility’s name, address, contact information, industrial sector(s), discharging waterbody, and location of the facility’s Stormwater Pollution Prevention Plan. For more information, please go to http://www.dec.ny.gov/chemical/62803.html.