Groundwater Watch: USGS Groundwater Levels on the Internet

The U.S. Geological Survey’s Groundwater Watch (http://groundwaterwatch.usgs.gov/) is a web-based product that displays networks of wells in addition to location maps, hydrographs, statistical summaries, and other details.  Data are provided to Groundwater Watch via the USGS National Water Information System’s publically-accessible database, NWISWeb.  Water-level measurements are uploaded to local USGS databases on a regular basis, as frequently as hourly.  These data are then updated nightly to NWISWeb and Groundwater Watch.  The product is extensible and, in 2011, several defined networks are available, including a real time network of nearly 1,400 wells, a climate response network of nearly 600 wells, a long-term network of wells with 20, 30, and 50 or more years of measurements, networks defined by Principal Aquifer, and an active water-level network of more than 20,000 wells. 

For each network, a U.S. map illustrates the distribution of wells in the individual network, and the statistical ranking of the most recent water-level measurement.  State and County maps provide a more local picture of groundwater conditions.  Individual well pages provide details about a specific well, and all available water-level data from the well.  A monthly statistical summary of groundwater levels is presented for wells that have at least 10 years of water-level measurements in a given month.  Water-level percentile distributions are presented, and the most recent measurement is categorized, and the associated symbol color-coded, among these percentile categories:  greater than the 90^th percentile,  76^th-90^th percentile, 25^th-75^th percentile, 10^th-24^th percentile, and less than the 10^th.

The value of groundwater data is illustrated by its use.  Groundwater Watch makes use of disparate groundwater-level monitoring data by organizing the data into a variety of relevant networks, calculating simple statistics, and providing timely data and information in an easy to use format.