Current conditions at selected sites 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 to the USGS every hour. Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data (of unverified accuracy and subject to revision). Most current data are provisional.

The same data accessed by the Current Conditions link above but including both active and discontinued sites with data for any part of the period October 1, 2007, through the present. Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data (of unverified accuracy and subject to revision).

Summary of all data for each day for the period of record and may represent the daily mean, median, maximum, minimum, and/or other derived value. Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data (of unverified accuracy and subject to revision). Example.

Statistics are computed from approved daily mean 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.

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.