Groundwater and Streamflow Information
Groundwater and Streamflow Information
Groundwater and surface water are among the Nation’s most important natural resources. The USGS provides unbiased, timely, and relevant information, studies, and data about water resources of the Nation. The NYWSC maintains a network of more than 300 surface water and 650 groundwater monitoring stations across New York State; over the years, the USGS has collected water-resources data at approximately 1.5 million sites in all 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands. The data collected at the various sites are synthesized in State-level, interstate, and international studies to evaluate resources not only in one State but also other States and countries that might be affected or may influence the condition of surface water and groundwater. The data collected are used in studies of water supplies, groundwater contamination, flooding, water stored in ice and the oceans, and the effects of climate and land use change and manmade influences.
Filter Total Items: 107
Long Island Precipitation and Recharge
Precipitation is water released from clouds in the form of rain, freezing rain, sleet, snow, or hail. It is the primary connection in the water cycle that provides for the delivery of atmospheric water to the Earth. Most precipitation falls as rain. Water seeping down from the land surface and reaching the water table adds to the groundwater and is called groundwater recharge. Groundwater is...
Long Island Surface Water
Streams either gain water from inflow of groundwater from the underlying aquifer or lose water by outflow to the underlying aquifer. Many streams do both, gaining in some reaches and losing in other reaches. Furthermore, the groundwater flow directions near any given stream can change seasonally as the altitude of the water table changes with respect to the stream-surface altitude or when rapid...
Long Island Groundwater
Approximately 30% of the world’s water is stored as groundwater. Groundwater moves very slowly, on the order of feet per day, however it is still part of the hydrologic cycle. Most of the water in the ground comes from precipitation that infiltrates downward from the land surface.
Long Island Hydrogeologic Units
Long Island’s aquifer system consists of a seaward-dipping wedge of mostly unconsolidated stratified sediments comprised of sand, gravel, silt and clay.
Long Island Fresh and Saltwater Relations/Interactions
Because saltwater has a greater density than freshwater, fresh groundwater in coastal aquifers will overlie any saltwater that is present in the aquifer at depth (Figure 14).
Long Island State of the Aquifer System
One of the most important concepts to understand is that volumes of water pumped from a groundwater system must come from somewhere and must cause a change in the groundwater system. Another important concept is that water table aquifers are hydraulically connected to the streams that drain them. Therefore, pumping water from aquifers that are hydraulically connected with surface-water bodies can...
Long Island Water Availability
The foundation of any groundwater analysis, including those analyses whose objective is to propose and evaluate alternative management strategies, is the availability of high-quality data. Some, such as precipitation data, are generally available and relatively easy to obtain at the time of a hydrologic analysis. Other data and information, such as geologic and hydrogeologic maps, can require...
Long Island Precipitation
The National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC) offers several types of climate information generated from examination of the data in the archives. These types of information include record temperatures, record precipitation and snowfall, climate extreme statistics, and other derived climate products. A collection of statistical weather and climate...
NWIS - the USGS Data Archive
As part of the U.S. Geological Survey's (USGS) program for disseminating water data within USGS, to USGS cooperators, and to the general public, the USGS maintains a distributed network of computers and fileservers for the acquisition, processing, review, and long-term storage of water data. This water data is collected at over 1.5 million sites around the country and at some border and...
Long Island Surface Water - Streamflow
Surface water current conditions are based on the most recent data from on-site automated recording equipment. Measurements are commonly recorded at a fixed interval of 15 to 60 minutes and transmitted by satallite uplink or telephone telemetry to the USGS every hour. Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data (of unverified...
Long Island Groundwater Levels
Water-level measurements from observation wells are the principal source of information about the hydrologic stresses acting on aquifers and how these stresses affect groundwater recharge, storage, and discharge (Taylor and Alley, 2001). Water-level measurements are made by many Federal, State, and local agencies.
Long Island Water Table and Surface Maps
The depth to the water table can be determined by installing wells that penetrate the top of the saturated zone just far enough to respond to water table fluctuations. Preparation of a water-table map requires that only wells that have their well screens installed near the water table be used. If the depth to water is measured at a number of such wells throughout an area of study, and if those...