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Data

USGS has been collecting hydrologic data in Long Island Sound and its watershed for decades. Collected data include surface-water discharge, continuous and discrete groundwater levels and water-quality sampling. The data are used for a variety of purposes related to the management of water resources in the basin. Explore data releases below.

Nitrogen Loads, Yields, and Associated Field Data Collected During Baseflow Conditions and Site Attributes for Small Basins Draining to Long Island Sound

During the spring and summer of 2022, the U.S. Geological Survey collected water-quality samples for nutrient analysis at 45 stations across the state of Connecticut and adjacent areas of New York and Rhode Island to better understand the groundwater discharge component of nitrogen loading to the Long Island Sound. The targeted stations were located in small drainage basins (less than 50 square ki

Nitrogen Concentrations and Loads and Seasonal Nitrogen Loads in Selected Long Island Sound Tributaries, Water Years 1995-2021 (ver. 1.1, February 2024)

This U.S. Geological Survey (USGS) data release presents tabular data on nitrogen concentrations and loads for multiple nitrogen species, and river discharge data used in the analysis of data collected from October 1994 to September 2021. Data on flow and nitrogen concentrations were analyzed using the USGS Exploration and Graphics for RivEr Trends (EGRET) R package, and the method of Weighted Reg

Hydroacoustic Data to Support Embayment Monitoring in Long Island Sound, Mystic and Norwalk Embayments, Connecticut, 2021-2022

This data release includes hydroacoustic data for the 2021 to 2022 water years at four stations. These stations are part of a discrete and continuous monitoring project in embayments on Long Island Sound to support nutrient management activities in Connecticut. The data were collected by the U.S Geological Survey (USGS) in cooperation with the Connecticut Department of Energy and Environmental Pro

MODFLOW-NWT and MODPATH groundwater flow models of steady-state conditions in coastal Connecticut and adjacent areas of New York and Rhode Island, as well as a nitrogen transport model of the Niantic River watershed

A steady-state groundwater flow model, using MODFLOW-NWT, was developed to better understand groundwater flow in coastal Connecticut and adjacent areas of New York and Rhode Island. Aquatic systems in and around Long Island Sound (LIS) provide a variety of ecological and economic benefits such as flood and storm protection, water filtration, recreation, habitat for commercially and recreationally

Summary simulated groundwater budgets and travel times for watersheds on the north shore of Long Island Sound

A steady-state groundwater flow model was developed for watersheds on the north shore of Long Island Sound in coastal Connecticut and adjacent areas of New York and Rhode Island. As part of the analysis, groundwater travel times and the components of the groundwater budget were calculated for each HUC12 basin within the model domain and for the watersheds of selected embayments identified by the C

Assessment of fecal contamination sources to Alley Creek, Queens County, New York: Results from a sediment resuspension experiment, thermal imagery, and additional sample collection, 2020-2021

In cooperation with the New York City Department of Environmental Protection (NYC DEP), the U.S. Geological Survey (USGS) collected water and bed sediment samples along Alley Creek (Queens, New York) to help determine likely sources of fecal bacteria to the creek and Little Neck Bay. Potential terrestrial sources include stormwater, sewage via combined sewer overflow (CSO) and compromised infrastr

Nitrogen concentrations and loads and seasonal nitrogen loads in selected Long Island Sound tributaries, water years 1995-2016

This U.S. Geological Survey data release presents tabular data on nitrogen concentrations and loads for multiple nitrogen species, and river discharge data used in the analysis of data collected from October 1994 to September 2016. Data on flow and nitrogen concentrations were analyzed using the USGS EGRET R package, and the method of WRTDS (Weighted Regression on Time Discharge and Season). Data

Sea-Floor Sediment and Imagery Data Collected in Long Island Sound, Connecticut and New York, 2017 and 2018

Two marine geological surveys were conducted in Long Island Sound, Connecticut and New York, in fall 2017 and spring 2018 by the U.S. Geological Survey, University of Connecticut, and University of New Haven through the Long Island Sound Mapping and Research Collaborative. Sea-floor images and videos were collected at 210 sampling sites within the survey area, and surficial sediment samples were c

Coastal wetlands of north shore Long Island, New York

This data release contains coastal wetland synthesis products for the geographic region of north shore Long Island, New York. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and mean tidal range, are calculated for smaller units delineated from a Digital Elevation Model, providing the spatial variability of physical factors that influence wetland health. T

Coastal wetlands of eastern Long Island, New York (ver. 2.0, March 2024)

This data release contains coastal wetland synthesis products for the geographic region of eastern Long Island, New York, including the north and south forks, Gardiners Island, and Fishers Island. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and mean tidal range, are calculated for smaller units delineated from a Digital Elevation Model, providing the s

High-resolution geophysical and sampling data collected at the mouth of Connecticut River, Old Saybrook to Essex, 2012, USGS Field Activity 2012-024-FA

A geophysical and geological survey was conducted at the mouth of Connecticut River from Old Saybrook to Essex, CT in September 2012. Approximately 227 linear-km of digital Chirp sub bottom (seismic-reflection) and 234-kHz interferometric sonar (bathymetric and backscatter) data were collected along with sediment samples, river-bed photographs and/or video at eighty-seven sites within the geophys

Coastal Groundwater Chemical Data from the North and South Shores of Long Island, New York

Groundwater data were collected in the spring and fall of 2008 from three sites representing different geological settings and biogeochemical conditions within the surficial glacial aquifer of Long Island, NY. Investigations were designed to examine the extent to which average vadose zone thickness in contributing watersheds controlled biogeochemical conditions and processes, including dissolved o