U.S. Geological Survey Hydrologic Monitoring on Long Island, New York

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The U.S. Geological Survey (USGS) is a science organization that provides impartial information on the health of our ecosystems and environment, the natural hazards that threaten us, the natural resources we rely on, the impacts of climate and land-use change, and the core science systems that help us provide timely, relevant, and usable information.

Because USGS data and analyses adhere to strict national protocols, findings are directly comparable across local, state, regional, and national levels; water issues in a specific watershed, municipality, or state can be compared to those in other geographic regions and at different periods of time; and large-scale syntheses and problem-solving in different regions and across the Nation are possible. The scientific, non-regulatory mission of the USGS means that the science is credible and relevant to many types of regulatory, management, policy, and jurisdictional disputes. Our sole product is impartial, credible, relevant, and timely information, equally accessible and available to all interested parties.



On Long Island, New York (Kings, Queens, Nassau, and Suffolk Counties), the USGS has operated and maintained a cooperative hydrologic-surveillance program since the early 1900’s. The current program, run out of the New York Water Science Center, Coram Program Office, consists of data collection from approximately 550 groundwater-monitoring wells (fig. 1), and 55 streams and 2 lakes (fig. 2). This program is funded cooperatively with other National, State, County, and local partners and provides the seamless, long-term data needed to accurately assess conditions and properly manage the region’s water resources and provides our cooperators, stakeholders, and the public with mission critical information.

map of Long Island with colored dots

 Figure 1 - Active USGS Groundwater-Monitoring Stations on Long Island, NY, by aquifer screened. More information about USGS Groundwater Monitoring on Long Island is available here(Public domain.)

Groundwater data are the primary focus of the USGS hydrologic-surveillance program on Long Island; however, because most streams, ponds, and lakes in the region are hydraulically connected with the shallow groundwater system, the USGS monitors stream discharge and lake levels as part of its hydrologic-surveillance network. Groundwater-level, lake-level, and stream-discharge data are all needed to accurately assess seasonal fluctuations and long-term trends in groundwater.

Map of Long Island with colored dots

Figure 2 - Active USGS Surface-Water Monitoring Stations on Long Island, NY, by measurement frequency. More information about USGS Surface-Water Monitoring on Long Island is available here(Public domain.)

Related Information

Data and information from the Long Island Hydrologic-Monitoring Program can be accessed from the following locations:

Information on the Long Island Groundwater-Monitoring Network is available from the “Long Island Groundwater Network” webpage.

Information on the Long Island Surface-Water Monitoring Network is available from the “Long Island Surface-Water Network” webpage.

Information on monthly hydrologic-conditions for streamflow and groundwater levels in New York State is available from the “Monthly Hydrologic Conditions for New York” webpage.

Information on local and regional floods and droughts is available from the “New York Flood Information” and “New York Drought Information” webpages.

All USGS groundwater and surface-water data collected by the USGS is entered into the USGS National Water Information System (NWIS), where it is reviewed and approved, and made available for display and retrieval from NWISWeb. Additionally, USGS groundwater, streamflow, and water-quality data are available through the USGS Groundwater Watch, USGS WaterWatch, and USGS Water Quality Watch websites.


Project Goals

  • Collect long-term hydrologic data using nationally consistent standards and techniques to provide the information needed to evaluate water availability, saltwater intrusion, drought and flooding susceptibility, wetlands health, and other hydrologic concerns.
  • Produce USGS regional water-table, potentiometric-surface, and depth-to-water maps, used by local agencies, water managers, engineers and consultants, and the public to assess groundwater flooding, contaminant movement, over-pumping, and saltwater intrusion issues across the region.
  • Provide the data needed for local, regional, and National hydrologic studies.
  • Provide prompt dissemination of collected data on NWISWeb and through other data sources.


Project Benefits

Hydrologic data collected from this project: (1) provides scientists and water managers with a seamless, island-wide data set of representative hydrologic conditions using nationally consistent data-collection techniques; (2) promotes the timely exchange of scientific information and research between the USGS, State, County, local agencies, and local water suppliers and managers; (3) allows for the production and revision of island-wide water-level, depth-to-water, and hydrogeologic maps by the USGS; (4) provides the data needed for regional and National hydrologic studies; (5) allows for the prompt dissemination of USGS collected data online through NWISWeb and other related outlets; and (6) in times of drought or flood, provides the data needed to properly manage the resource and inform critical flood-response activities by emergency-managers and communities.

In addition to the benefits to local stakeholders, this program will provide relevance to the USGS mission by (1) advancing the knowledge of the regional hydrologic system, (2) furnishing hydrologic data that contributes to the protection of life and property, and (3) providing standardized, quality-assured data to National data bases available to the public and used to advance the understanding of regional and temporal variations in hydrologic conditions and processes. These continuous historical datasets would also be available for statistical analyses to improve our knowledge and understanding of the long- and short-term changes that occur in the hydrologic system when various natural and man-induced stresses are applied, and are essential for assessing future management and development scenarios for the region’s water resources.


Project Funding

USGS hydrologic surveillance and research is primarily funded through the Cooperative Water Program (CWP), which is the USGS’s “bottom-up, on-the-ground” program designed to bring State and local water-science needs and decision making together with USGS national capabilities. The CWP provides the foundation for the USGS’s strong and robust water-monitoring networks (quantity and quality), and supports interpretative studies that cover a wide range of issues that are important to the USGS water mission, and that inform State and local water decisions. The significant tie to State and local concerns, through cooperator interaction, allows the CWP to respond to emerging water issues on a local level, while concurrently raising those issues to regional and National visibility.

This shared funding model allows the USGS to most efficiently monitor and evaluate the regions hydrologic resources without putting an undue burden on any one cooperator. In addition, this model brings added value to the cooperative program, by allowing the USGS to leverage other nationally an locally funded research to provide at no cost to the cooperator additional resources and expertise useful for describing and evaluating complex resource-related problems and emerging issues. Additional information on the mission of the USGS can be found here and on the CWP here.