(29 sites)
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Real-time data are time-series (recorded at fixed intervals) data from automated equipment and represent
the most current hydrologic conditions. Measurements are commonly recorded
at 5-60 minute intervals and transmitted to the NWIS database every 1-4 hours.
Real-time data are available online for 31 days.
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(382 sites)
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Daily values are summarized from time-series
data for each day for the period of record and may represent the daily
mean, median, maximum, minimum, and/or other derived value. Daily values include
approved, quality-assured data that may be published, and more recent
provisional data, whose accuracy has not been verified.
Example.
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(382 sites)
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Statistics are computed from approved daily mean time-series data at each site.
These links provide summaries of approved historical daily values for daily,
monthly, and annual (water year or calendar year) time periods.
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(7,474 sites)
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Manual measurements of depth to water in wells. These measurements are
often used to supplement and (or) verify the accuracy of the instantaneous measurements.
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Introduction
The Ground-Water database contains ground-water site
inventory, ground-water level data, and water-quality data.
The ground-water
site inventory consists of more than 850,000 records of wells,
springs, test holes, tunnels,drains, and excavations in the United
States. Available site descriptive information includes well location
information (latitude and longitude, well depth, site use, water use,
and aquifer).
The USGS annually monitors ground-water levels in
thousands of wells in the United States.
Ground-water level data are collected and stored as either discrete
ground-water level measurements or as continuous record. Data from some
of the continuous record stations are relayed to USGS offices
nationwide through telephone lines or by satellite transmissions
providing access to realtime
ground-water data.
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